diff --git a/.github/workflows/compatibility.yml b/.github/workflows/compatibility.yml
deleted file mode 100644
index 8994b624b..000000000
--- a/.github/workflows/compatibility.yml
+++ /dev/null
@@ -1,20 +0,0 @@
-name: Check compatibility
-on:
-  pull_request:
-  push:
-    branches: [main]
-jobs:
-  test:
-    name: Check source code compatibility
-    runs-on: ubuntu-latest
-    container: swift:6.0.3
-    steps:
-      - name: Checkout
-        uses: actions/checkout@v4
-      - uses: swiftwasm/setup-swiftwasm@v2
-      - name: Run Test
-        run: |
-          set -eux
-          cd Examples/Basic
-          swift build --swift-sdk wasm32-unknown-wasi --static-swift-stdlib
-          swift build --swift-sdk wasm32-unknown-wasi -Xswiftc -DJAVASCRIPTKIT_WITHOUT_WEAKREFS --static-swift-stdlib
diff --git a/.github/workflows/test.yml b/.github/workflows/test.yml
index c50de248a..486f7b6bf 100644
--- a/.github/workflows/test.yml
+++ b/.github/workflows/test.yml
@@ -38,8 +38,10 @@ jobs:
         id: setup-swiftwasm
         with:
           target: ${{ matrix.entry.target }}
-      - name: Configure Swift SDK
-        run: echo "SWIFT_SDK_ID=${{ steps.setup-swiftwasm.outputs.swift-sdk-id }}" >> $GITHUB_ENV
+      - name: Configure environment variables
+        run: |
+          echo "SWIFT_SDK_ID=${{ steps.setup-swiftwasm.outputs.swift-sdk-id }}" >> $GITHUB_ENV
+          echo "SWIFT_PATH=$(dirname $(which swiftc))" >> $GITHUB_ENV
       - run: make bootstrap
       - run: make unittest
         # Skip unit tests with uwasi because its proc_exit throws
@@ -49,6 +51,7 @@ jobs:
         run: |
           make regenerate_swiftpm_resources
           git diff --exit-code Sources/JavaScriptKit/Runtime
+      - run: swift test --package-path ./Plugins/PackageToJS
 
   native-build:
     # Check native build to make it easy to develop applications by Xcode
@@ -64,19 +67,3 @@ jobs:
       - run: swift build
         env:
           DEVELOPER_DIR: /Applications/${{ matrix.xcode }}.app/Contents/Developer/
-
-  embedded-build:
-    name: Build for embedded target
-    runs-on: ubuntu-22.04
-    strategy:
-      matrix:
-        entry:
-          - os: ubuntu-22.04
-            toolchain:
-              download-url: https://download.swift.org/development/ubuntu2204/swift-DEVELOPMENT-SNAPSHOT-2025-02-26-a/swift-DEVELOPMENT-SNAPSHOT-2025-02-26-a-ubuntu22.04.tar.gz
-    steps:
-      - uses: actions/checkout@v4
-      - uses: ./.github/actions/install-swift
-        with:
-          download-url: ${{ matrix.entry.toolchain.download-url }}
-      - run: ./Examples/Embedded/build.sh
diff --git a/Makefile b/Makefile
index c8b79b4ab..a2ad1526a 100644
--- a/Makefile
+++ b/Makefile
@@ -6,6 +6,7 @@ SWIFT_BUILD_FLAGS := --swift-sdk $(SWIFT_SDK_ID)
 .PHONY: bootstrap
 bootstrap:
 	npm ci
+	npx playwright install
 
 .PHONY: build
 build:
diff --git a/Plugins/PackageToJS/Package.swift b/Plugins/PackageToJS/Package.swift
index 1cc9318bd..57ccf3cf9 100644
--- a/Plugins/PackageToJS/Package.swift
+++ b/Plugins/PackageToJS/Package.swift
@@ -7,6 +7,10 @@ let package = Package(
     platforms: [.macOS(.v13)],
     targets: [
         .target(name: "PackageToJS"),
-        .testTarget(name: "PackageToJSTests", dependencies: ["PackageToJS"]),
+        .testTarget(
+            name: "PackageToJSTests",
+            dependencies: ["PackageToJS"],
+            exclude: ["__Snapshots__"]
+        ),
     ]
 )
diff --git a/Plugins/PackageToJS/Sources/MiniMake.swift b/Plugins/PackageToJS/Sources/MiniMake.swift
index 04e781690..3544a80f3 100644
--- a/Plugins/PackageToJS/Sources/MiniMake.swift
+++ b/Plugins/PackageToJS/Sources/MiniMake.swift
@@ -14,13 +14,13 @@ struct MiniMake {
 
     /// Information about a task enough to capture build
     /// graph changes
-    struct TaskInfo: Codable {
+    struct TaskInfo: Encodable {
         /// Input tasks not yet built
         let wants: [TaskKey]
-        /// Set of files that must be built before this task
-        let inputs: [String]
-        /// Output task name
-        let output: String
+        /// Set of file paths that must be built before this task
+        let inputs: [BuildPath]
+        /// Output file path
+        let output: BuildPath
         /// Attributes of the task
         let attributes: [TaskAttribute]
         /// Salt for the task, used to differentiate between otherwise identical tasks
@@ -30,25 +30,23 @@ struct MiniMake {
     /// A task to build
     struct Task {
         let info: TaskInfo
-        /// Input tasks not yet built
+        /// Input tasks (files and phony tasks) not yet built
         let wants: Set<TaskKey>
         /// Attributes of the task
         let attributes: Set<TaskAttribute>
-        /// Display name of the task
-        let displayName: String
         /// Key of the task
         let key: TaskKey
         /// Build operation
-        let build: (Task) throws -> Void
+        let build: (_ task: Task, _ scope: VariableScope) throws -> Void
         /// Whether the task is done
         var isDone: Bool
 
-        var inputs: [String] { self.info.inputs }
-        var output: String { self.info.output }
+        var inputs: [BuildPath] { self.info.inputs }
+        var output: BuildPath { self.info.output }
     }
 
     /// A task key
-    struct TaskKey: Codable, Hashable, Comparable, CustomStringConvertible {
+    struct TaskKey: Encodable, Hashable, Comparable, CustomStringConvertible {
         let id: String
         var description: String { self.id }
 
@@ -56,15 +54,45 @@ struct MiniMake {
             self.id = id
         }
 
+        func encode(to encoder: any Encoder) throws {
+            var container = encoder.singleValueContainer()
+            try container.encode(self.id)
+        }
+
         static func < (lhs: TaskKey, rhs: TaskKey) -> Bool { lhs.id < rhs.id }
     }
 
+    struct VariableScope {
+        let variables: [String: String]
+
+        func resolve(path: BuildPath) -> URL {
+            var components = [String]()
+            for component in path.components {
+                switch component {
+                case .prefix(let variable):
+                    guard let value = variables[variable] else {
+                        fatalError("Build path variable \"\(variable)\" not defined!")
+                    }
+                    components.append(value)
+                case .constant(let path):
+                    components.append(path)
+                }
+            }
+            guard let first = components.first else {
+                fatalError("Build path is empty")
+            }
+            var url = URL(fileURLWithPath: first)
+            for component in components.dropFirst() {
+                url = url.appending(path: component)
+            }
+            return url
+        }
+    }
+
     /// All tasks in the build system
     private var tasks: [TaskKey: Task]
     /// Whether to explain why tasks are built
     private var shouldExplain: Bool
-    /// Current working directory at the time the build started
-    private let buildCwd: String
     /// Prints progress of the build
     private var printProgress: ProgressPrinter.PrintProgress
 
@@ -74,20 +102,16 @@ struct MiniMake {
     ) {
         self.tasks = [:]
         self.shouldExplain = explain
-        self.buildCwd = FileManager.default.currentDirectoryPath
         self.printProgress = printProgress
     }
 
     /// Adds a task to the build system
     mutating func addTask(
-        inputFiles: [String] = [], inputTasks: [TaskKey] = [], output: String,
+        inputFiles: [BuildPath] = [], inputTasks: [TaskKey] = [], output: BuildPath,
         attributes: [TaskAttribute] = [], salt: (any Encodable)? = nil,
-        build: @escaping (Task) throws -> Void
+        build: @escaping (_ task: Task, _ scope: VariableScope) throws -> Void
     ) -> TaskKey {
-        let displayName =
-            output.hasPrefix(self.buildCwd)
-            ? String(output.dropFirst(self.buildCwd.count + 1)) : output
-        let taskKey = TaskKey(id: output)
+        let taskKey = TaskKey(id: output.description)
         let saltData = try! salt.map {
             let encoder = JSONEncoder()
             encoder.outputFormatting = .sortedKeys
@@ -99,7 +123,7 @@ struct MiniMake {
         )
         self.tasks[taskKey] = Task(
             info: info, wants: Set(inputTasks), attributes: Set(attributes),
-            displayName: displayName, key: taskKey, build: build, isDone: false)
+            key: taskKey, build: build, isDone: false)
         return taskKey
     }
 
@@ -107,9 +131,12 @@ struct MiniMake {
     ///
     /// This fingerprint must be stable across builds and must change
     /// if the build graph changes in any way.
-    func computeFingerprint(root: TaskKey) throws -> Data {
+    func computeFingerprint(root: TaskKey, prettyPrint: Bool = false) throws -> Data {
         let encoder = JSONEncoder()
         encoder.outputFormatting = .sortedKeys
+        if prettyPrint {
+            encoder.outputFormatting.insert(.prettyPrinted)
+        }
         let tasks = self.tasks.sorted { $0.key < $1.key }.map { $0.value.info }
         return try encoder.encode(tasks)
     }
@@ -126,7 +153,13 @@ struct MiniMake {
 
     /// Prints progress of the build
     struct ProgressPrinter {
-        typealias PrintProgress = (_ subject: Task, _ total: Int, _ built: Int, _ message: String) -> Void
+        struct Context {
+            let subject: Task
+            let total: Int
+            let built: Int
+            let scope: VariableScope
+        }
+        typealias PrintProgress = (_ context: Context, _ message: String) -> Void
 
         /// Total number of tasks to build
         let total: Int
@@ -145,17 +178,17 @@ struct MiniMake {
         private static var yellow: String { "\u{001B}[33m" }
         private static var reset: String { "\u{001B}[0m" }
 
-        mutating func started(_ task: Task) {
-            self.print(task, "\(Self.green)building\(Self.reset)")
+        mutating func started(_ task: Task, scope: VariableScope) {
+            self.print(task, scope, "\(Self.green)building\(Self.reset)")
         }
 
-        mutating func skipped(_ task: Task) {
-            self.print(task, "\(Self.yellow)skipped\(Self.reset)")
+        mutating func skipped(_ task: Task, scope: VariableScope) {
+            self.print(task, scope, "\(Self.yellow)skipped\(Self.reset)")
         }
 
-        private mutating func print(_ task: Task, _ message: @autoclosure () -> String) {
+        private mutating func print(_ task: Task, _ scope: VariableScope, _ message: @autoclosure () -> String) {
             guard !task.attributes.contains(.silent) else { return }
-            self.printProgress(task, self.total, self.built, message())
+            self.printProgress(Context(subject: task, total: self.total, built: self.built, scope: scope), message())
             self.built += 1
         }
     }
@@ -176,32 +209,32 @@ struct MiniMake {
     }
 
     /// Cleans all outputs of all tasks
-    func cleanEverything() {
+    func cleanEverything(scope: VariableScope) {
         for task in self.tasks.values {
-            try? FileManager.default.removeItem(atPath: task.output)
+            try? FileManager.default.removeItem(at: scope.resolve(path: task.output))
         }
     }
 
     /// Starts building
-    func build(output: TaskKey) throws {
+    func build(output: TaskKey, scope: VariableScope) throws {
         /// Returns true if any of the task's inputs have a modification date later than the task's output
         func shouldBuild(task: Task) -> Bool {
             if task.attributes.contains(.phony) {
                 return true
             }
-            let outputURL = URL(fileURLWithPath: task.output)
-            if !FileManager.default.fileExists(atPath: task.output) {
+            let outputURL = scope.resolve(path: task.output)
+            if !FileManager.default.fileExists(atPath: outputURL.path) {
                 explain("Task \(task.output) should be built because it doesn't exist")
                 return true
             }
             let outputMtime = try? outputURL.resourceValues(forKeys: [.contentModificationDateKey])
                 .contentModificationDate
             return task.inputs.contains { input in
-                let inputURL = URL(fileURLWithPath: input)
+                let inputURL = scope.resolve(path: input)
                 // Ignore directory modification times
                 var isDirectory: ObjCBool = false
                 let fileExists = FileManager.default.fileExists(
-                    atPath: input, isDirectory: &isDirectory)
+                    atPath: inputURL.path, isDirectory: &isDirectory)
                 if fileExists && isDirectory.boolValue {
                     return false
                 }
@@ -238,10 +271,10 @@ struct MiniMake {
             }
 
             if shouldBuild(task: task) {
-                progressPrinter.started(task)
-                try task.build(task)
+                progressPrinter.started(task, scope: scope)
+                try task.build(task, scope)
             } else {
-                progressPrinter.skipped(task)
+                progressPrinter.skipped(task, scope: scope)
             }
             task.isDone = true
             tasks[taskKey] = task
@@ -249,3 +282,45 @@ struct MiniMake {
         try runTask(taskKey: output)
     }
 }
+
+struct BuildPath: Encodable, Hashable, CustomStringConvertible {
+    enum Component: Hashable, CustomStringConvertible {
+        case prefix(variable: String)
+        case constant(String)
+
+        var description: String {
+            switch self {
+            case .prefix(let variable): return "$\(variable)"
+            case .constant(let path): return path
+            }
+        }
+    }
+    fileprivate let components: [Component]
+
+    var description: String { self.components.map(\.description).joined(separator: "/") }
+
+    init(phony: String) {
+        self.components = [.constant(phony)]
+    }
+
+    init(prefix: String, _ tail: String...) {
+        self.components = [.prefix(variable: prefix)] + tail.map(Component.constant)
+    }
+
+    init(absolute: String) {
+        self.components = [.constant(absolute)]
+    }
+
+    private init(components: [Component]) {
+        self.components = components
+    }
+
+    func appending(path: String) -> BuildPath {
+        return BuildPath(components: self.components + [.constant(path)])
+    }
+
+    func encode(to encoder: any Encoder) throws {
+        var container = encoder.singleValueContainer()
+        try container.encode(self.description)
+    }
+}
diff --git a/Plugins/PackageToJS/Sources/PackageToJS.swift b/Plugins/PackageToJS/Sources/PackageToJS.swift
index 44aaf532d..e54a2a910 100644
--- a/Plugins/PackageToJS/Sources/PackageToJS.swift
+++ b/Plugins/PackageToJS/Sources/PackageToJS.swift
@@ -9,7 +9,7 @@ struct PackageToJS {
         /// Whether to explain the build plan
         var explain: Bool = false
         /// Whether to use CDN for dependency packages
-        var useCDN: Bool
+        var useCDN: Bool = false
     }
 
     struct BuildOptions {
@@ -39,6 +39,37 @@ struct PackageToJS {
         /// The options for packaging
         var packageOptions: PackageOptions
     }
+
+    static func deriveBuildConfiguration(wasmProductArtifact: URL) -> (configuration: String, triple: String) {
+        // e.g. path/to/.build/wasm32-unknown-wasi/debug/Basic.wasm -> ("debug", "wasm32-unknown-wasi")
+
+        // First, resolve symlink to get the actual path as SwiftPM 6.0 and earlier returns unresolved
+        // symlink path for product artifact.
+        let wasmProductArtifact = wasmProductArtifact.resolvingSymlinksInPath()
+        let buildConfiguration = wasmProductArtifact.deletingLastPathComponent().lastPathComponent
+        let triple = wasmProductArtifact.deletingLastPathComponent().deletingLastPathComponent().lastPathComponent
+        return (buildConfiguration, triple)
+    }
+
+    static func runTest(testRunner: URL, currentDirectoryURL: URL, extraArguments: [String]) throws {
+        let node = try which("node")
+        let arguments = ["--experimental-wasi-unstable-preview1", testRunner.path] + extraArguments
+        print("Running test...")
+        logCommandExecution(node.path, arguments)
+
+        let task = Process()
+        task.executableURL = node
+        task.arguments = arguments
+        task.currentDirectoryURL = currentDirectoryURL
+        try task.forwardTerminationSignals {
+            try task.run()
+            task.waitUntilExit()
+        }
+        // swift-testing returns EX_UNAVAILABLE (which is 69 in wasi-libc) for "no tests found"
+        guard task.terminationStatus == 0 || task.terminationStatus == 69 else {
+            throw PackageToJSError("Test failed with status \(task.terminationStatus)")
+        }
+    }
 }
 
 struct PackageToJSError: Swift.Error, CustomStringConvertible {
@@ -49,45 +80,24 @@ struct PackageToJSError: Swift.Error, CustomStringConvertible {
     }
 }
 
-/// Plans the build for packaging.
-struct PackagingPlanner {
-    /// The options for packaging
-    let options: PackageToJS.PackageOptions
-    /// The package ID of the package that this plugin is running on
-    let packageId: String
-    /// The directory of the package that contains this plugin
-    let selfPackageDir: URL
-    /// The path of this file itself, used to capture changes of planner code
-    let selfPath: String
-    /// The directory for the final output
-    let outputDir: URL
-    /// The directory for intermediate files
-    let intermediatesDir: URL
-    /// The filename of the .wasm file
-    let wasmFilename = "main.wasm"
-    /// The path to the .wasm product artifact
-    let wasmProductArtifact: URL
+protocol PackagingSystem {
+    func createDirectory(atPath: String) throws
+    func syncFile(from: String, to: String) throws
+    func writeFile(atPath: String, content: Data) throws
 
-    init(
-        options: PackageToJS.PackageOptions,
-        packageId: String,
-        pluginWorkDirectoryURL: URL,
-        selfPackageDir: URL,
-        outputDir: URL,
-        wasmProductArtifact: URL
-    ) {
-        self.options = options
-        self.packageId = packageId
-        self.selfPackageDir = selfPackageDir
-        self.outputDir = outputDir
-        self.intermediatesDir = pluginWorkDirectoryURL.appending(path: outputDir.lastPathComponent + ".tmp")
-        self.selfPath = String(#filePath)
-        self.wasmProductArtifact = wasmProductArtifact
-    }
+    func wasmOpt(_ arguments: [String], input: String, output: String) throws
+    func npmInstall(packageDir: String) throws
+}
 
-    // MARK: - Primitive build operations
+extension PackagingSystem {
+    func createDirectory(atPath: String) throws {
+        guard !FileManager.default.fileExists(atPath: atPath) else { return }
+        try FileManager.default.createDirectory(
+            atPath: atPath, withIntermediateDirectories: true, attributes: nil
+        )
+    }
 
-    private static func syncFile(from: String, to: String) throws {
+    func syncFile(from: String, to: String) throws {
         if FileManager.default.fileExists(atPath: to) {
             try FileManager.default.removeItem(atPath: to)
         }
@@ -97,14 +107,41 @@ struct PackagingPlanner {
         )
     }
 
-    private static func createDirectory(atPath: String) throws {
-        guard !FileManager.default.fileExists(atPath: atPath) else { return }
-        try FileManager.default.createDirectory(
-            atPath: atPath, withIntermediateDirectories: true, attributes: nil
-        )
+    func writeFile(atPath: String, content: Data) throws {
+        do {
+            try content.write(to: URL(fileURLWithPath: atPath))
+        } catch {
+            throw PackageToJSError("Failed to write file \(atPath): \(error)")
+        }
+    }
+}
+
+final class DefaultPackagingSystem: PackagingSystem {
+
+    private let printWarning: (String) -> Void
+
+    init(printWarning: @escaping (String) -> Void) {
+        self.printWarning = printWarning
+    }
+
+    func npmInstall(packageDir: String) throws {
+        try runCommand(try which("npm"), ["-C", packageDir, "install"])
     }
 
-    private static func runCommand(_ command: URL, _ arguments: [String]) throws {
+    lazy var warnMissingWasmOpt: () = {
+        self.printWarning("Warning: wasm-opt is not installed, optimizations will not be applied")
+    }()
+
+    func wasmOpt(_ arguments: [String], input: String, output: String) throws {
+        guard let wasmOpt = try? which("wasm-opt") else {
+            _ = warnMissingWasmOpt
+            try FileManager.default.copyItem(atPath: input, toPath: output)
+            return
+        }
+        try runCommand(wasmOpt, arguments + ["-o", output, input])
+    }
+
+    private func runCommand(_ command: URL, _ arguments: [String]) throws {
         let task = Process()
         task.executableURL = command
         task.arguments = arguments
@@ -115,6 +152,73 @@ struct PackagingPlanner {
             throw PackageToJSError("Command failed with status \(task.terminationStatus)")
         }
     }
+}
+
+internal func which(_ executable: String) throws -> URL {
+    let pathSeparator: Character
+    #if os(Windows)
+        pathSeparator = ";"
+    #else
+        pathSeparator = ":"
+    #endif
+    let paths = ProcessInfo.processInfo.environment["PATH"]!.split(separator: pathSeparator)
+    for path in paths {
+        let url = URL(fileURLWithPath: String(path)).appendingPathComponent(executable)
+        if FileManager.default.isExecutableFile(atPath: url.path) {
+            return url
+        }
+    }
+    throw PackageToJSError("Executable \(executable) not found in PATH")
+}
+
+/// Plans the build for packaging.
+struct PackagingPlanner {
+    /// The options for packaging
+    let options: PackageToJS.PackageOptions
+    /// The package ID of the package that this plugin is running on
+    let packageId: String
+    /// The directory of the package that contains this plugin
+    let selfPackageDir: BuildPath
+    /// The path of this file itself, used to capture changes of planner code
+    let selfPath: BuildPath
+    /// The directory for the final output
+    let outputDir: BuildPath
+    /// The directory for intermediate files
+    let intermediatesDir: BuildPath
+    /// The filename of the .wasm file
+    let wasmFilename = "main.wasm"
+    /// The path to the .wasm product artifact
+    let wasmProductArtifact: BuildPath
+    /// The build configuration
+    let configuration: String
+    /// The target triple
+    let triple: String
+    /// The system interface to use
+    let system: any PackagingSystem
+
+    init(
+        options: PackageToJS.PackageOptions,
+        packageId: String,
+        intermediatesDir: BuildPath,
+        selfPackageDir: BuildPath,
+        outputDir: BuildPath,
+        wasmProductArtifact: BuildPath,
+        configuration: String,
+        triple: String,
+        selfPath: BuildPath = BuildPath(absolute: #filePath),
+        system: any PackagingSystem
+    ) {
+        self.options = options
+        self.packageId = packageId
+        self.selfPackageDir = selfPackageDir
+        self.outputDir = outputDir
+        self.intermediatesDir = intermediatesDir
+        self.selfPath = selfPath
+        self.wasmProductArtifact = wasmProductArtifact
+        self.configuration = configuration
+        self.triple = triple
+        self.system = system
+    }
 
     // MARK: - Build plans
 
@@ -123,23 +227,12 @@ struct PackagingPlanner {
         make: inout MiniMake,
         buildOptions: PackageToJS.BuildOptions
     ) throws -> MiniMake.TaskKey {
-        let (allTasks, _, _) = try planBuildInternal(
+        let (allTasks, _, _, _) = try planBuildInternal(
             make: &make, splitDebug: buildOptions.splitDebug, noOptimize: buildOptions.noOptimize
         )
         return make.addTask(
-            inputTasks: allTasks, output: "all", attributes: [.phony, .silent]
-        ) { _ in }
-    }
-
-    func deriveBuildConfiguration() -> (configuration: String, triple: String) {
-        // e.g. path/to/.build/wasm32-unknown-wasi/debug/Basic.wasm -> ("debug", "wasm32-unknown-wasi")
-
-        // First, resolve symlink to get the actual path as SwiftPM 6.0 and earlier returns unresolved
-        // symlink path for product artifact.
-        let wasmProductArtifact = self.wasmProductArtifact.resolvingSymlinksInPath()
-        let buildConfiguration = wasmProductArtifact.deletingLastPathComponent().lastPathComponent
-        let triple = wasmProductArtifact.deletingLastPathComponent().deletingLastPathComponent().lastPathComponent
-        return (buildConfiguration, triple)
+            inputTasks: allTasks, output: BuildPath(phony: "all"), attributes: [.phony, .silent]
+        ) { _, _ in }
     }
 
     private func planBuildInternal(
@@ -148,55 +241,49 @@ struct PackagingPlanner {
     ) throws -> (
         allTasks: [MiniMake.TaskKey],
         outputDirTask: MiniMake.TaskKey,
+        intermediatesDirTask: MiniMake.TaskKey,
         packageJsonTask: MiniMake.TaskKey
     ) {
         // Prepare output directory
         let outputDirTask = make.addTask(
-            inputFiles: [selfPath], output: outputDir.path, attributes: [.silent]
+            inputFiles: [selfPath], output: outputDir, attributes: [.silent]
         ) {
-            try Self.createDirectory(atPath: $0.output)
+            try system.createDirectory(atPath: $1.resolve(path: $0.output).path)
         }
 
         var packageInputs: [MiniMake.TaskKey] = []
 
         // Guess the build configuration from the parent directory name of .wasm file
-        let (buildConfiguration, _) = deriveBuildConfiguration()
         let wasm: MiniMake.TaskKey
 
         let shouldOptimize: Bool
-        let wasmOptPath = try? which("wasm-opt")
-        if buildConfiguration == "debug" {
+        if self.configuration == "debug" {
             shouldOptimize = false
         } else {
-            if wasmOptPath != nil {
-                shouldOptimize = !noOptimize
-            } else {
-                print("Warning: wasm-opt not found in PATH, skipping optimizations")
-                shouldOptimize = false
-            }
+            shouldOptimize = !noOptimize
         }
 
         let intermediatesDirTask = make.addTask(
-            inputFiles: [selfPath], output: intermediatesDir.path, attributes: [.silent]
+            inputFiles: [selfPath], output: intermediatesDir, attributes: [.silent]
         ) {
-            try Self.createDirectory(atPath: $0.output)
+            try system.createDirectory(atPath: $1.resolve(path: $0.output).path)
         }
 
-        let finalWasmPath = outputDir.appending(path: wasmFilename).path
+        let finalWasmPath = outputDir.appending(path: wasmFilename)
 
-        if let wasmOptPath = wasmOptPath, shouldOptimize {
+        if shouldOptimize {
             // Optimize the wasm in release mode
             // If splitDebug is true, we need to place the DWARF-stripped wasm file (but "name" section remains)
             // in the output directory.
-            let stripWasmPath = (splitDebug ? outputDir : intermediatesDir).appending(path: wasmFilename + ".debug").path
+            let stripWasmPath = (splitDebug ? outputDir : intermediatesDir).appending(path: wasmFilename + ".debug")
 
             // First, strip DWARF sections as their existence enables DWARF preserving mode in wasm-opt
             let stripWasm = make.addTask(
-                inputFiles: [selfPath, wasmProductArtifact.path], inputTasks: [outputDirTask, intermediatesDirTask],
+                inputFiles: [selfPath, wasmProductArtifact], inputTasks: [outputDirTask, intermediatesDirTask],
                 output: stripWasmPath
             ) {
                 print("Stripping DWARF debug info...")
-                try Self.runCommand(wasmOptPath, [wasmProductArtifact.path, "--strip-dwarf", "--debuginfo", "-o", $0.output])
+                try system.wasmOpt(["--strip-dwarf", "--debuginfo"], input: $1.resolve(path: wasmProductArtifact).path, output: $1.resolve(path: $0.output).path)
             }
             // Then, run wasm-opt with all optimizations
             wasm = make.addTask(
@@ -204,15 +291,15 @@ struct PackagingPlanner {
                 output: finalWasmPath
             ) {
                 print("Optimizing the wasm file...")
-                try Self.runCommand(wasmOptPath, [stripWasmPath, "-Os", "-o", $0.output])
+                try system.wasmOpt(["-Os"], input: $1.resolve(path: stripWasmPath).path, output: $1.resolve(path: $0.output).path)
             }
         } else {
             // Copy the wasm product artifact
             wasm = make.addTask(
-                inputFiles: [selfPath, wasmProductArtifact.path], inputTasks: [outputDirTask],
+                inputFiles: [selfPath, wasmProductArtifact], inputTasks: [outputDirTask],
                 output: finalWasmPath
             ) {
-                try Self.syncFile(from: wasmProductArtifact.path, to: $0.output)
+                try system.syncFile(from: $1.resolve(path: wasmProductArtifact).path, to: $1.resolve(path: $0.output).path)
             }
         }
         packageInputs.append(wasm)
@@ -220,22 +307,24 @@ struct PackagingPlanner {
         let wasmImportsPath = intermediatesDir.appending(path: "wasm-imports.json")
         let wasmImportsTask = make.addTask(
             inputFiles: [selfPath, finalWasmPath], inputTasks: [outputDirTask, intermediatesDirTask, wasm],
-            output: wasmImportsPath.path
+            output: wasmImportsPath
         ) {
-            let metadata = try parseImports(moduleBytes: Array(try Data(contentsOf: URL(fileURLWithPath: finalWasmPath))))
+            let metadata = try parseImports(
+                moduleBytes: try Data(contentsOf: URL(fileURLWithPath: $1.resolve(path: finalWasmPath).path))
+            )
             let jsonEncoder = JSONEncoder()
             jsonEncoder.outputFormatting = .prettyPrinted
             let jsonData = try jsonEncoder.encode(metadata)
-            try jsonData.write(to: URL(fileURLWithPath: $0.output))
+            try system.writeFile(atPath: $1.resolve(path: $0.output).path, content: jsonData)
         }
 
         packageInputs.append(wasmImportsTask)
 
         let platformsDir = outputDir.appending(path: "platforms")
         let platformsDirTask = make.addTask(
-            inputFiles: [selfPath], output: platformsDir.path, attributes: [.silent]
+            inputFiles: [selfPath], output: platformsDir, attributes: [.silent]
         ) {
-            try Self.createDirectory(atPath: $0.output)
+            try system.createDirectory(atPath: $1.resolve(path: $0.output).path)
         }
 
         let packageJsonTask = planCopyTemplateFile(
@@ -259,40 +348,39 @@ struct PackagingPlanner {
         ] {
             packageInputs.append(planCopyTemplateFile(
                 make: &make, file: file, output: output, outputDirTask: outputDirTask,
-                inputFiles: [wasmImportsPath.path], inputTasks: [platformsDirTask, wasmImportsTask],
-                wasmImportsPath: wasmImportsPath.path
+                inputFiles: [wasmImportsPath], inputTasks: [platformsDirTask, wasmImportsTask],
+                wasmImportsPath: wasmImportsPath
             ))
         }
-        return (packageInputs, outputDirTask, packageJsonTask)
+        return (packageInputs, outputDirTask, intermediatesDirTask, packageJsonTask)
     }
 
     /// Construct the test build plan and return the root task key
     func planTestBuild(
         make: inout MiniMake
-    ) throws -> (rootTask: MiniMake.TaskKey, binDir: URL) {
-        var (allTasks, outputDirTask, packageJsonTask) = try planBuildInternal(
+    ) throws -> (rootTask: MiniMake.TaskKey, binDir: BuildPath) {
+        var (allTasks, outputDirTask, intermediatesDirTask, packageJsonTask) = try planBuildInternal(
             make: &make, splitDebug: false, noOptimize: false
         )
 
         // Install npm dependencies used in the test harness
-        let npm = try which("npm")
         allTasks.append(make.addTask(
             inputFiles: [
                 selfPath,
-                outputDir.appending(path: "package.json").path,
-            ], inputTasks: [outputDirTask, packageJsonTask],
-            output: intermediatesDir.appending(path: "npm-install.stamp").path
+                outputDir.appending(path: "package.json"),
+            ], inputTasks: [intermediatesDirTask, packageJsonTask],
+            output: intermediatesDir.appending(path: "npm-install.stamp")
         ) {
-            try Self.runCommand(npm, ["-C", outputDir.path, "install"])
-            _ = FileManager.default.createFile(atPath: $0.output, contents: Data(), attributes: nil)
+            try system.npmInstall(packageDir: $1.resolve(path: outputDir).path)
+            try system.writeFile(atPath: $1.resolve(path: $0.output).path, content: Data())
         })
 
         let binDir = outputDir.appending(path: "bin")
         let binDirTask = make.addTask(
             inputFiles: [selfPath], inputTasks: [outputDirTask],
-            output: binDir.path
+            output: binDir
         ) {
-            try Self.createDirectory(atPath: $0.output)
+            try system.createDirectory(atPath: $1.resolve(path: $0.output).path)
         }
         allTasks.append(binDirTask)
 
@@ -309,8 +397,8 @@ struct PackagingPlanner {
             ))
         }
         let rootTask = make.addTask(
-            inputTasks: allTasks, output: "all", attributes: [.phony, .silent]
-        ) { _ in }
+            inputTasks: allTasks, output: BuildPath(phony: "all"), attributes: [.phony, .silent]
+        ) { _, _ in }
         return (rootTask, binDir)
     }
 
@@ -319,9 +407,9 @@ struct PackagingPlanner {
         file: String,
         output: String,
         outputDirTask: MiniMake.TaskKey,
-        inputFiles: [String],
+        inputFiles: [BuildPath],
         inputTasks: [MiniMake.TaskKey],
-        wasmImportsPath: String? = nil
+        wasmImportsPath: BuildPath? = nil
     ) -> MiniMake.TaskKey {
 
         struct Salt: Encodable {
@@ -330,7 +418,6 @@ struct PackagingPlanner {
         }
 
         let inputPath = selfPackageDir.appending(path: file)
-        let (_, triple) = deriveBuildConfiguration()
         let conditions = [
             "USE_SHARED_MEMORY": triple == "wasm32-unknown-wasip1-threads",
             "IS_WASI": triple.hasPrefix("wasm32-unknown-wasi"),
@@ -343,13 +430,14 @@ struct PackagingPlanner {
         let salt = Salt(conditions: conditions, substitutions: constantSubstitutions)
 
         return make.addTask(
-            inputFiles: [selfPath, inputPath.path] + inputFiles, inputTasks: [outputDirTask] + inputTasks,
-            output: outputDir.appending(path: output).path, salt: salt
+            inputFiles: [selfPath, inputPath] + inputFiles, inputTasks: [outputDirTask] + inputTasks,
+            output: outputDir.appending(path: output), salt: salt
         ) {
             var substitutions = constantSubstitutions
 
             if let wasmImportsPath = wasmImportsPath {
-                let importEntries = try JSONDecoder().decode([ImportEntry].self, from: Data(contentsOf: URL(fileURLWithPath: wasmImportsPath)))
+                let wasmImportsPath = $1.resolve(path: wasmImportsPath)
+                let importEntries = try JSONDecoder().decode([ImportEntry].self, from: Data(contentsOf: wasmImportsPath))
                 let memoryImport = importEntries.first { $0.module == "env" && $0.name == "memory" }
                 if case .memory(let type) = memoryImport?.kind {
                     substitutions["PACKAGE_TO_JS_MEMORY_INITIAL"] = "\(type.minimum)"
@@ -358,33 +446,17 @@ struct PackagingPlanner {
                 }
             }
 
+            let inputPath = $1.resolve(path: inputPath)
             var content = try String(contentsOf: inputPath, encoding: .utf8)
             let options = PreprocessOptions(conditions: conditions, substitutions: substitutions)
-            content = try preprocess(source: content, file: file, options: options)
-            try content.write(toFile: $0.output, atomically: true, encoding: .utf8)
+            content = try preprocess(source: content, file: inputPath.path, options: options)
+            try system.writeFile(atPath: $1.resolve(path: $0.output).path, content: Data(content.utf8))
         }
     }
 }
 
 // MARK: - Utilities
 
-func which(_ executable: String) throws -> URL {
-    let pathSeparator: Character
-    #if os(Windows)
-        pathSeparator = ";"
-    #else
-        pathSeparator = ":"
-    #endif
-    let paths = ProcessInfo.processInfo.environment["PATH"]!.split(separator: pathSeparator)
-    for path in paths {
-        let url = URL(fileURLWithPath: String(path)).appendingPathComponent(executable)
-        if FileManager.default.isExecutableFile(atPath: url.path) {
-            return url
-        }
-    }
-    throw PackageToJSError("Executable \(executable) not found in PATH")
-}
-
 func logCommandExecution(_ command: String, _ arguments: [String]) {
     var fullArguments = [command]
     fullArguments.append(contentsOf: arguments)
diff --git a/Plugins/PackageToJS/Sources/PackageToJSPlugin.swift b/Plugins/PackageToJS/Sources/PackageToJSPlugin.swift
index 7e12eb94f..4074a8218 100644
--- a/Plugins/PackageToJS/Sources/PackageToJSPlugin.swift
+++ b/Plugins/PackageToJS/Sources/PackageToJSPlugin.swift
@@ -122,7 +122,8 @@ struct PackageToJSPlugin: CommandPlugin {
             make: &make, buildOptions: buildOptions)
         cleanIfBuildGraphChanged(root: rootTask, make: make, context: context)
         print("Packaging...")
-        try make.build(output: rootTask)
+        let scope = MiniMake.VariableScope(variables: [:])
+        try make.build(output: rootTask, scope: scope)
         print("Packaging finished")
     }
 
@@ -159,7 +160,8 @@ struct PackageToJSPlugin: CommandPlugin {
         //       not worth the overhead)
         var productArtifact: URL?
         for fileExtension in ["wasm", "xctest"] {
-            let path = ".build/debug/\(productName).\(fileExtension)"
+            let packageDir = context.package.directoryURL
+            let path = packageDir.appending(path: ".build/debug/\(productName).\(fileExtension)").path
             if FileManager.default.fileExists(atPath: path) {
                 productArtifact = URL(fileURLWithPath: path)
                 break
@@ -192,10 +194,11 @@ struct PackageToJSPlugin: CommandPlugin {
             make: &make)
         cleanIfBuildGraphChanged(root: rootTask, make: make, context: context)
         print("Packaging tests...")
-        try make.build(output: rootTask)
+        let scope = MiniMake.VariableScope(variables: [:])
+        try make.build(output: rootTask, scope: scope)
         print("Packaging tests finished")
 
-        let testRunner = binDir.appending(path: "test.js")
+        let testRunner = scope.resolve(path: binDir.appending(path: "test.js"))
         if !testOptions.buildOnly {
             var testJsArguments: [String] = []
             var testFrameworkArguments: [String] = []
@@ -212,38 +215,18 @@ struct PackageToJSPlugin: CommandPlugin {
             if testOptions.inspect {
                 testJsArguments += ["--inspect"]
             }
-            try runTest(
-                testRunner: testRunner, context: context,
+            try PackageToJS.runTest(
+                testRunner: testRunner, currentDirectoryURL: context.pluginWorkDirectoryURL,
                 extraArguments: testJsArguments + ["--"] + testFrameworkArguments + testOptions.filter
             )
-            try runTest(
-                testRunner: testRunner, context: context,
+            try PackageToJS.runTest(
+                testRunner: testRunner, currentDirectoryURL: context.pluginWorkDirectoryURL,
                 extraArguments: testJsArguments + ["--", "--testing-library", "swift-testing"] + testFrameworkArguments
                     + testOptions.filter.flatMap { ["--filter", $0] }
             )
         }
     }
 
-    private func runTest(testRunner: URL, context: PluginContext, extraArguments: [String]) throws {
-        let node = try which("node")
-        let arguments = ["--experimental-wasi-unstable-preview1", testRunner.path] + extraArguments
-        print("Running test...")
-        logCommandExecution(node.path, arguments)
-
-        let task = Process()
-        task.executableURL = node
-        task.arguments = arguments
-        task.currentDirectoryURL = context.pluginWorkDirectoryURL
-        try task.forwardTerminationSignals {
-            try task.run()
-            task.waitUntilExit()
-        }
-        // swift-testing returns EX_UNAVAILABLE (which is 69 in wasi-libc) for "no tests found"
-        guard task.terminationStatus == 0 || task.terminationStatus == 69 else {
-            throw PackageToJSError("Test failed with status \(task.terminationStatus)")
-        }
-    }
-
     private func buildWasm(productName: String, context: PluginContext) throws
         -> PackageManager.BuildResult
     {
@@ -282,14 +265,18 @@ struct PackageToJSPlugin: CommandPlugin {
         let lastBuildFingerprint = try? Data(contentsOf: buildFingerprint)
         let currentBuildFingerprint = try? make.computeFingerprint(root: root)
         if lastBuildFingerprint != currentBuildFingerprint {
-            print("Build graph changed, cleaning...")
-            make.cleanEverything()
+            printStderr("Build graph changed, cleaning...")
+            make.cleanEverything(scope: MiniMake.VariableScope(variables: [:]))
         }
         try? currentBuildFingerprint?.write(to: buildFingerprint)
     }
 
-    private func printProgress(task: MiniMake.Task, total: Int, built: Int, message: String) {
-        printStderr("[\(built + 1)/\(total)] \(task.displayName): \(message)")
+    private func printProgress(context: MiniMake.ProgressPrinter.Context, message: String) {
+        let buildCwd = FileManager.default.currentDirectoryPath
+        let outputPath = context.scope.resolve(path: context.subject.output).path
+        let displayName = outputPath.hasPrefix(buildCwd)
+            ? String(outputPath.dropFirst(buildCwd.count + 1)) : outputPath
+        printStderr("[\(context.built + 1)/\(context.total)] \(displayName): \(message)")
     }
 }
 
@@ -457,13 +444,19 @@ extension PackagingPlanner {
         outputDir: URL,
         wasmProductArtifact: URL
     ) {
+        let outputBaseName = outputDir.lastPathComponent
+        let (configuration, triple) = PackageToJS.deriveBuildConfiguration(wasmProductArtifact: wasmProductArtifact)
+        let system = DefaultPackagingSystem(printWarning: printStderr)
         self.init(
             options: options,
             packageId: context.package.id,
-            pluginWorkDirectoryURL: context.pluginWorkDirectoryURL,
-            selfPackageDir: selfPackage.directoryURL,
-            outputDir: outputDir,
-            wasmProductArtifact: wasmProductArtifact
+            intermediatesDir: BuildPath(absolute: context.pluginWorkDirectoryURL.appending(path: outputBaseName + ".tmp").path),
+            selfPackageDir: BuildPath(absolute: selfPackage.directoryURL.path),
+            outputDir: BuildPath(absolute: outputDir.path),
+            wasmProductArtifact: BuildPath(absolute: wasmProductArtifact.path),
+            configuration: configuration,
+            triple: triple,
+            system: system
         )
     }
 }
diff --git a/Plugins/PackageToJS/Sources/ParseWasm.swift b/Plugins/PackageToJS/Sources/ParseWasm.swift
index 1cec9e43f..a35b69561 100644
--- a/Plugins/PackageToJS/Sources/ParseWasm.swift
+++ b/Plugins/PackageToJS/Sources/ParseWasm.swift
@@ -1,3 +1,5 @@
+import struct Foundation.Data
+
 /// Represents the type of value in WebAssembly
 enum ValueType: String, Codable {
     case i32
@@ -62,10 +64,10 @@ struct ImportEntry: Codable {
 
 /// Parse state for WebAssembly parsing
 private class ParseState {
-    private let moduleBytes: [UInt8]
+    private let moduleBytes: Data
     private var offset: Int
     
-    init(moduleBytes: [UInt8]) {
+    init(moduleBytes: Data) {
         self.moduleBytes = moduleBytes
         self.offset = 0
     }
@@ -158,7 +160,7 @@ enum ParseError: Error {
 /// - Parameter moduleBytes: The WebAssembly module bytes
 /// - Returns: Array of import entries
 /// - Throws: ParseError if the module bytes are invalid
-func parseImports(moduleBytes: [UInt8]) throws -> [ImportEntry] {
+func parseImports(moduleBytes: Data) throws -> [ImportEntry] {
     let parseState = ParseState(moduleBytes: moduleBytes)
     try parseMagicNumber(parseState)
     try parseVersion(parseState)
diff --git a/Plugins/PackageToJS/Tests/ExampleProjectTests.swift b/Plugins/PackageToJS/Tests/ExampleProjectTests.swift
deleted file mode 100644
index 1bcc25d48..000000000
--- a/Plugins/PackageToJS/Tests/ExampleProjectTests.swift
+++ /dev/null
@@ -1,6 +0,0 @@
-import Testing
-
-@Suite struct ExampleProjectTests {
-    @Test func example() throws {
-    }
-}
diff --git a/Plugins/PackageToJS/Tests/ExampleTests.swift b/Plugins/PackageToJS/Tests/ExampleTests.swift
new file mode 100644
index 000000000..be5d8e60b
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/ExampleTests.swift
@@ -0,0 +1,185 @@
+import Foundation
+import Testing
+
+@testable import PackageToJS
+
+extension Trait where Self == ConditionTrait {
+    static var requireSwiftSDK: ConditionTrait {
+        .enabled(
+            if: ProcessInfo.processInfo.environment["SWIFT_SDK_ID"] != nil
+                && ProcessInfo.processInfo.environment["SWIFT_PATH"] != nil,
+            "Requires SWIFT_SDK_ID and SWIFT_PATH environment variables"
+        )
+    }
+
+    static func requireSwiftSDK(triple: String) -> ConditionTrait {
+        .enabled(
+            if: ProcessInfo.processInfo.environment["SWIFT_SDK_ID"] != nil
+                && ProcessInfo.processInfo.environment["SWIFT_PATH"] != nil
+                && ProcessInfo.processInfo.environment["SWIFT_SDK_ID"]!.hasSuffix(triple),
+            "Requires SWIFT_SDK_ID and SWIFT_PATH environment variables"
+        )
+    }
+
+    static var requireEmbeddedSwift: ConditionTrait {
+        // Check if $SWIFT_PATH/../lib/swift/embedded/wasm32-unknown-none-wasm/ exists
+        return .enabled(
+            if: {
+                guard let swiftPath = ProcessInfo.processInfo.environment["SWIFT_PATH"] else {
+                    return false
+                }
+                let embeddedPath = URL(fileURLWithPath: swiftPath).deletingLastPathComponent()
+                    .appending(path: "lib/swift/embedded/wasm32-unknown-none-wasm")
+                return FileManager.default.fileExists(atPath: embeddedPath.path)
+            }(),
+            "Requires embedded Swift SDK under $SWIFT_PATH/../lib/swift/embedded"
+        )
+    }
+}
+
+@Suite struct ExampleTests {
+    static func getSwiftSDKID() -> String? {
+        ProcessInfo.processInfo.environment["SWIFT_SDK_ID"]
+    }
+
+    static let repoPath = URL(fileURLWithPath: #filePath)
+        .deletingLastPathComponent()
+        .deletingLastPathComponent()
+        .deletingLastPathComponent()
+        .deletingLastPathComponent()
+
+    static func copyRepository(to destination: URL) throws {
+        try FileManager.default.createDirectory(
+            atPath: destination.path, withIntermediateDirectories: true, attributes: nil)
+        let ignore = [
+            ".git",
+            ".vscode",
+            ".build",
+            "node_modules",
+        ]
+
+        let enumerator = FileManager.default.enumerator(atPath: repoPath.path)!
+        while let file = enumerator.nextObject() as? String {
+            let sourcePath = repoPath.appending(path: file)
+            let destinationPath = destination.appending(path: file)
+            if ignore.contains(where: { file.hasSuffix($0) }) {
+                enumerator.skipDescendants()
+                continue
+            }
+            // Skip directories
+            var isDirectory: ObjCBool = false
+            if FileManager.default.fileExists(atPath: sourcePath.path, isDirectory: &isDirectory) {
+                if isDirectory.boolValue {
+                    continue
+                }
+            }
+
+            do {
+                try FileManager.default.createDirectory(
+                    at: destinationPath.deletingLastPathComponent(),
+                    withIntermediateDirectories: true, attributes: nil)
+                try FileManager.default.copyItem(at: sourcePath, to: destinationPath)
+            } catch {
+                print("Failed to copy \(sourcePath) to \(destinationPath): \(error)")
+                throw error
+            }
+        }
+    }
+
+    typealias RunSwift = (_ args: [String], _ env: [String: String]) throws -> Void
+
+    func withPackage(at path: String, body: (URL, _ runSwift: RunSwift) throws -> Void) throws {
+        try withTemporaryDirectory { tempDir, retain in
+            let destination = tempDir.appending(path: Self.repoPath.lastPathComponent)
+            try Self.copyRepository(to: destination)
+            try body(destination.appending(path: path)) { args, env in
+                let process = Process()
+                process.executableURL = URL(
+                    fileURLWithPath: "swift",
+                    relativeTo: URL(
+                        fileURLWithPath: ProcessInfo.processInfo.environment["SWIFT_PATH"]!))
+                process.arguments = args
+                process.currentDirectoryURL = destination.appending(path: path)
+                process.environment = ProcessInfo.processInfo.environment.merging(env) { _, new in
+                    new
+                }
+                let stdoutPath = tempDir.appending(path: "stdout.txt")
+                let stderrPath = tempDir.appending(path: "stderr.txt")
+                _ = FileManager.default.createFile(atPath: stdoutPath.path, contents: nil)
+                _ = FileManager.default.createFile(atPath: stderrPath.path, contents: nil)
+                process.standardOutput = try FileHandle(forWritingTo: stdoutPath)
+                process.standardError = try FileHandle(forWritingTo: stderrPath)
+
+                try process.run()
+                process.waitUntilExit()
+                if process.terminationStatus != 0 {
+                    retain = true
+                }
+                try #require(
+                    process.terminationStatus == 0,
+                    """
+                    Swift package should build successfully, check \(destination.appending(path: path).path) for details
+                    stdout: \(stdoutPath.path)
+                    stderr: \(stderrPath.path)
+
+                    \((try? String(contentsOf: stdoutPath, encoding: .utf8)) ?? "<<stdout is empty>>")
+                    \((try? String(contentsOf: stderrPath, encoding: .utf8)) ?? "<<stderr is empty>>")
+                    """
+                )
+            }
+        }
+    }
+
+    @Test(.requireSwiftSDK)
+    func basic() throws {
+        let swiftSDKID = try #require(Self.getSwiftSDKID())
+        try withPackage(at: "Examples/Basic") { packageDir, runSwift in
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js"], [:])
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "-Xswiftc", "-DJAVASCRIPTKIT_WITHOUT_WEAKREFS", "js"], [:])
+        }
+    }
+
+    @Test(.requireSwiftSDK)
+    func testing() throws {
+        let swiftSDKID = try #require(Self.getSwiftSDKID())
+        try withPackage(at: "Examples/Testing") { packageDir, runSwift in
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js", "test"], [:])
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js", "test", "--environment", "browser"], [:])
+        }
+    }
+
+    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasip1-threads"))
+    func multithreading() throws {
+        let swiftSDKID = try #require(Self.getSwiftSDKID())
+        try withPackage(at: "Examples/Multithreading") { packageDir, runSwift in
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js"], [:])
+        }
+    }
+
+    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasip1-threads"))
+    func offscreenCanvas() throws {
+        let swiftSDKID = try #require(Self.getSwiftSDKID())
+        try withPackage(at: "Examples/OffscrenCanvas") { packageDir, runSwift in
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js"], [:])
+        }
+    }
+
+    @Test(.requireSwiftSDK(triple: "wasm32-unknown-wasip1-threads"))
+    func actorOnWebWorker() throws {
+        let swiftSDKID = try #require(Self.getSwiftSDKID())
+        try withPackage(at: "Examples/ActorOnWebWorker") { packageDir, runSwift in
+            try runSwift(["package", "--swift-sdk", swiftSDKID, "js"], [:])
+        }
+    }
+
+    @Test(.requireEmbeddedSwift) func embedded() throws {
+        try withPackage(at: "Examples/Embedded") { packageDir, runSwift in
+            try runSwift(
+                ["package", "--triple", "wasm32-unknown-none-wasm", "-c", "release", "js"],
+                [
+                    "JAVASCRIPTKIT_EXPERIMENTAL_EMBEDDED_WASM": "true"
+                ]
+            )
+        }
+    }
+}
diff --git a/Plugins/PackageToJS/Tests/MiniMakeTests.swift b/Plugins/PackageToJS/Tests/MiniMakeTests.swift
index bb097115c..b15a87607 100644
--- a/Plugins/PackageToJS/Tests/MiniMakeTests.swift
+++ b/Plugins/PackageToJS/Tests/MiniMakeTests.swift
@@ -6,65 +6,75 @@ import Testing
 @Suite struct MiniMakeTests {
     // Test basic task management functionality
     @Test func basicTaskManagement() throws {
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
-            let outputPath = tempDir.appendingPathComponent("output.txt").path
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let outDir = BuildPath(prefix: "OUTPUT")
 
-            let task = make.addTask(output: outputPath) { task in
-                try "Hello".write(toFile: task.output, atomically: true, encoding: .utf8)
+            let task = make.addTask(output: outDir.appending(path: "output.txt")) {
+                try "Hello".write(toFile: $1.resolve(path: $0.output).path, atomically: true, encoding: .utf8)
             }
 
-            try make.build(output: task)
-            let content = try String(contentsOfFile: outputPath, encoding: .utf8)
+            try make.build(output: task, scope: MiniMake.VariableScope(variables: [
+                "OUTPUT": tempDir.path,
+            ]))
+            let content = try String(contentsOfFile: tempDir.appendingPathComponent("output.txt").path, encoding: .utf8)
             #expect(content == "Hello")
         }
     }
 
     // Test that task dependencies are handled correctly
     @Test func taskDependencies() throws {
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
-            let input = tempDir.appendingPathComponent("input.txt").path
-            let intermediate = tempDir.appendingPathComponent("intermediate.txt").path
-            let output = tempDir.appendingPathComponent("output.txt").path
-
-            try "Input".write(toFile: input, atomically: true, encoding: .utf8)
-
-            let intermediateTask = make.addTask(inputFiles: [input], output: intermediate) { task in
-                let content = try String(contentsOfFile: task.inputs[0], encoding: .utf8)
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let prefix = BuildPath(prefix: "PREFIX")
+            let scope = MiniMake.VariableScope(variables: [
+                "PREFIX": tempDir.path,
+            ])
+            let input = prefix.appending(path: "input.txt")
+            let intermediate = prefix.appending(path: "intermediate.txt")
+            let output = prefix.appending(path: "output.txt")
+
+            try "Input".write(toFile: scope.resolve(path: input).path, atomically: true, encoding: .utf8)
+
+            let intermediateTask = make.addTask(inputFiles: [input], output: intermediate) { task, outputURL in
+                let content = try String(contentsOfFile: scope.resolve(path: task.inputs[0]).path, encoding: .utf8)
                 try (content + " processed").write(
-                    toFile: task.output, atomically: true, encoding: .utf8)
+                    toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
 
             let finalTask = make.addTask(
                 inputFiles: [intermediate], inputTasks: [intermediateTask], output: output
-            ) { task in
-                let content = try String(contentsOfFile: task.inputs[0], encoding: .utf8)
+            ) { task, scope in
+                let content = try String(contentsOfFile: scope.resolve(path: task.inputs[0]).path, encoding: .utf8)
                 try (content + " final").write(
-                    toFile: task.output, atomically: true, encoding: .utf8)
+                    toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
 
-            try make.build(output: finalTask)
-            let content = try String(contentsOfFile: output, encoding: .utf8)
+            try make.build(output: finalTask, scope: scope)
+            let content = try String(contentsOfFile: scope.resolve(path: output).path, encoding: .utf8)
             #expect(content == "Input processed final")
         }
     }
 
     // Test that phony tasks are always rebuilt
     @Test func phonyTask() throws {
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
-            let outputPath = tempDir.appendingPathComponent("phony.txt").path
-            try "Hello".write(toFile: outputPath, atomically: true, encoding: .utf8)
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let phonyName = "phony.txt"
+            let outputPath = BuildPath(prefix: "OUTPUT").appending(path: phonyName)
+            try "Hello".write(toFile: tempDir.appendingPathComponent(phonyName).path, atomically: true, encoding: .utf8)
             var buildCount = 0
 
-            let task = make.addTask(output: outputPath, attributes: [.phony]) { task in
+            let task = make.addTask(output: outputPath, attributes: [.phony]) { task, scope in
                 buildCount += 1
-                try String(buildCount).write(toFile: task.output, atomically: true, encoding: .utf8)
+                try String(buildCount).write(toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
 
-            try make.build(output: task)
-            try make.build(output: task)
+            let scope = MiniMake.VariableScope(variables: [
+                "OUTPUT": tempDir.path,
+            ])
+            try make.build(output: task, scope: scope)
+            try make.build(output: task, scope: scope)
 
             #expect(buildCount == 2, "Phony task should always rebuild")
         }
@@ -72,13 +82,13 @@ import Testing
 
     // Test that the same build graph produces stable fingerprints
     @Test func fingerprintStability() throws {
-        var make1 = MiniMake(printProgress: { _, _, _, _ in })
-        var make2 = MiniMake(printProgress: { _, _, _, _ in })
+        var make1 = MiniMake(printProgress: { _, _ in })
+        var make2 = MiniMake(printProgress: { _, _ in })
 
-        let output1 = "output1.txt"
+        let output1 = BuildPath(prefix: "OUTPUT")
 
-        let task1 = make1.addTask(output: output1) { _ in }
-        let task2 = make2.addTask(output: output1) { _ in }
+        let task1 = make1.addTask(output: output1) { _, _ in }
+        let task2 = make2.addTask(output: output1) { _, _ in }
 
         let fingerprint1 = try make1.computeFingerprint(root: task1)
         let fingerprint2 = try make2.computeFingerprint(root: task2)
@@ -88,114 +98,130 @@ import Testing
 
     // Test that rebuilds are controlled by timestamps
     @Test func timestampBasedRebuild() throws {
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
-            let input = tempDir.appendingPathComponent("input.txt").path
-            let output = tempDir.appendingPathComponent("output.txt").path
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let prefix = BuildPath(prefix: "PREFIX")
+            let scope = MiniMake.VariableScope(variables: [
+                "PREFIX": tempDir.path,
+            ])
+            let input = prefix.appending(path: "input.txt")
+            let output = prefix.appending(path: "output.txt")
             var buildCount = 0
 
-            try "Initial".write(toFile: input, atomically: true, encoding: .utf8)
+            try "Initial".write(toFile: scope.resolve(path: input).path, atomically: true, encoding: .utf8)
 
-            let task = make.addTask(inputFiles: [input], output: output) { task in
+            let task = make.addTask(inputFiles: [input], output: output) { task, scope in
                 buildCount += 1
-                let content = try String(contentsOfFile: task.inputs[0], encoding: .utf8)
-                try content.write(toFile: task.output, atomically: true, encoding: .utf8)
+                let content = try String(contentsOfFile: scope.resolve(path: task.inputs[0]).path, encoding: .utf8)
+                try content.write(toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
 
             // First build
-            try make.build(output: task)
+            try make.build(output: task, scope: scope)
             #expect(buildCount == 1, "First build should occur")
 
             // Second build without changes
-            try make.build(output: task)
+            try make.build(output: task, scope: scope)
             #expect(buildCount == 1, "No rebuild should occur if input is not modified")
 
             // Modify input and rebuild
-            try "Modified".write(toFile: input, atomically: true, encoding: .utf8)
-            try make.build(output: task)
+            try "Modified".write(toFile: scope.resolve(path: input).path, atomically: true, encoding: .utf8)
+            try make.build(output: task, scope: scope)
             #expect(buildCount == 2, "Should rebuild when input is modified")
         }
     }
 
     // Test that silent tasks execute without output
     @Test func silentTask() throws {
-        try withTemporaryDirectory { tempDir in
+        try withTemporaryDirectory { tempDir, _ in
             var messages: [(String, Int, Int, String)] = []
             var make = MiniMake(
-                printProgress: { task, total, built, message in
-                    messages.append((URL(fileURLWithPath: task.output).lastPathComponent, total, built, message))
+                printProgress: { ctx, message in
+                    messages.append((ctx.subject.output.description, ctx.total, ctx.built, message))
                 }
             )
-            let silentOutputPath = tempDir.appendingPathComponent("silent.txt").path
-            let silentTask = make.addTask(output: silentOutputPath, attributes: [.silent]) { task in
-                try "Silent".write(toFile: task.output, atomically: true, encoding: .utf8)
+            let prefix = BuildPath(prefix: "PREFIX")
+            let scope = MiniMake.VariableScope(variables: [
+                "PREFIX": tempDir.path,
+            ])
+            let silentOutputPath = prefix.appending(path: "silent.txt")
+            let silentTask = make.addTask(output: silentOutputPath, attributes: [.silent]) { task, scope in
+                try "Silent".write(toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
-            let finalOutputPath = tempDir.appendingPathComponent("output.txt").path
+            let finalOutputPath = prefix.appending(path: "output.txt")
             let task = make.addTask(
                 inputTasks: [silentTask], output: finalOutputPath
-            ) { task in
-                try "Hello".write(toFile: task.output, atomically: true, encoding: .utf8)
+            ) { task, scope in
+                try "Hello".write(toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
             }
 
-            try make.build(output: task)
-            #expect(FileManager.default.fileExists(atPath: silentOutputPath), "Silent task should still create output file")
-            #expect(FileManager.default.fileExists(atPath: finalOutputPath), "Final task should create output file")
+            try make.build(output: task, scope: scope)
+            #expect(FileManager.default.fileExists(atPath: scope.resolve(path: silentOutputPath).path), "Silent task should still create output file")
+            #expect(FileManager.default.fileExists(atPath: scope.resolve(path: finalOutputPath).path), "Final task should create output file")
             try #require(messages.count == 1, "Should print progress for the final task")
-            #expect(messages[0] == ("output.txt", 1, 0, "\u{1B}[32mbuilding\u{1B}[0m"))
+            #expect(messages[0] == ("$PREFIX/output.txt", 1, 0, "\u{1B}[32mbuilding\u{1B}[0m"))
         }
     }
 
     // Test that error cases are handled appropriately
     @Test func errorWhileBuilding() throws {
         struct BuildError: Error {}
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
-            let output = tempDir.appendingPathComponent("error.txt").path
-
-            let task = make.addTask(output: output) { task in
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let prefix = BuildPath(prefix: "PREFIX")
+            let scope = MiniMake.VariableScope(variables: [
+                "PREFIX": tempDir.path,
+            ])
+            let output = prefix.appending(path: "error.txt")
+
+            let task = make.addTask(output: output) { task, scope in
                 throw BuildError()
             }
 
             #expect(throws: BuildError.self) {
-                try make.build(output: task)
+                try make.build(output: task, scope: scope)
             }
         }
     }
 
     // Test that cleanup functionality works correctly
     @Test func cleanup() throws {
-        try withTemporaryDirectory { tempDir in
-            var make = MiniMake(printProgress: { _, _, _, _ in })
+        try withTemporaryDirectory { tempDir, _ in
+            var make = MiniMake(printProgress: { _, _ in })
+            let prefix = BuildPath(prefix: "PREFIX")
+            let scope = MiniMake.VariableScope(variables: [
+                "PREFIX": tempDir.path,
+            ])
             let outputs = [
-                tempDir.appendingPathComponent("clean1.txt").path,
-                tempDir.appendingPathComponent("clean2.txt").path,
+                prefix.appending(path: "clean1.txt"),
+                prefix.appending(path: "clean2.txt"),
             ]
 
             // Create tasks and build them
             let tasks = outputs.map { output in
-                make.addTask(output: output) { task in
-                    try "Content".write(toFile: task.output, atomically: true, encoding: .utf8)
+                make.addTask(output: output) { task, scope in
+                    try "Content".write(toFile: scope.resolve(path: task.output).path, atomically: true, encoding: .utf8)
                 }
             }
 
             for task in tasks {
-                try make.build(output: task)
+                try make.build(output: task, scope: scope)
             }
 
             // Verify files exist
             for output in outputs {
                 #expect(
-                    FileManager.default.fileExists(atPath: output),
+                    FileManager.default.fileExists(atPath: scope.resolve(path: output).path),
                     "Output file should exist before cleanup")
             }
 
             // Clean everything
-            make.cleanEverything()
+            make.cleanEverything(scope: scope)
 
             // Verify files are removed
             for output in outputs {
                 #expect(
-                    !FileManager.default.fileExists(atPath: output),
+                    !FileManager.default.fileExists(atPath: scope.resolve(path: output).path),
                     "Output file should not exist after cleanup")
             }
         }
diff --git a/Plugins/PackageToJS/Tests/PackagingPlannerTests.swift b/Plugins/PackageToJS/Tests/PackagingPlannerTests.swift
new file mode 100644
index 000000000..7269bea2d
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/PackagingPlannerTests.swift
@@ -0,0 +1,92 @@
+import Foundation
+import Testing
+
+@testable import PackageToJS
+
+@Suite struct PackagingPlannerTests {
+    struct BuildSnapshot: Codable, Equatable {
+        let npmInstalls: [String]
+    }
+    class TestPackagingSystem: PackagingSystem {
+        var npmInstallCalls: [String] = []
+        func npmInstall(packageDir: String) throws {
+            npmInstallCalls.append(packageDir)
+        }
+
+        func wasmOpt(_ arguments: [String], input: String, output: String) throws {
+            try FileManager.default.copyItem(
+                at: URL(fileURLWithPath: input), to: URL(fileURLWithPath: output))
+        }
+    }
+
+    func snapshotBuildPlan(
+        filePath: String = #filePath, function: String = #function,
+        sourceLocation: SourceLocation = #_sourceLocation,
+        variant: String? = nil,
+        body: (inout MiniMake) throws -> MiniMake.TaskKey
+    ) throws {
+        var make = MiniMake(explain: false, printProgress: { _, _ in })
+        let rootKey = try body(&make)
+        let fingerprint = try make.computeFingerprint(root: rootKey, prettyPrint: true)
+        try assertSnapshot(
+            filePath: filePath, function: function, sourceLocation: sourceLocation,
+            variant: variant, input: fingerprint
+        )
+    }
+
+    @Test(arguments: [
+        (variant: "debug", configuration: "debug", splitDebug: false, noOptimize: false),
+        (variant: "release", configuration: "release", splitDebug: false, noOptimize: false),
+        (variant: "release_split_debug", configuration: "release", splitDebug: true, noOptimize: false),
+        (variant: "release_no_optimize", configuration: "release", splitDebug: false, noOptimize: true),
+    ])
+    func planBuild(variant: String, configuration: String, splitDebug: Bool, noOptimize: Bool) throws {
+        let options = PackageToJS.PackageOptions()
+        let system = TestPackagingSystem()
+        let planner = PackagingPlanner(
+            options: options,
+            packageId: "test",
+            intermediatesDir: BuildPath(prefix: "INTERMEDIATES"),
+            selfPackageDir: BuildPath(prefix: "SELF_PACKAGE"),
+            outputDir: BuildPath(prefix: "OUTPUT"),
+            wasmProductArtifact: BuildPath(prefix: "WASM_PRODUCT_ARTIFACT"),
+            configuration: configuration,
+            triple: "wasm32-unknown-wasi",
+            selfPath: BuildPath(prefix: "PLANNER_SOURCE_PATH"),
+            system: system
+        )
+        try snapshotBuildPlan(variant: variant) { make in
+            try planner.planBuild(
+                make: &make,
+                buildOptions: PackageToJS.BuildOptions(
+                    product: "test",
+                    splitDebug: splitDebug,
+                    noOptimize: noOptimize,
+                    packageOptions: options
+                )
+            )
+        }
+    }
+
+    @Test func planTestBuild() throws {
+        let options = PackageToJS.PackageOptions()
+        let system = TestPackagingSystem()
+        let planner = PackagingPlanner(
+            options: options,
+            packageId: "test",
+            intermediatesDir: BuildPath(prefix: "INTERMEDIATES"),
+            selfPackageDir: BuildPath(prefix: "SELF_PACKAGE"),
+            outputDir: BuildPath(prefix: "OUTPUT"),
+            wasmProductArtifact: BuildPath(prefix: "WASM_PRODUCT_ARTIFACT"),
+            configuration: "debug",
+            triple: "wasm32-unknown-wasi",
+            selfPath: BuildPath(prefix: "PLANNER_SOURCE_PATH"),
+            system: system
+        )
+        try snapshotBuildPlan() { make in
+            let (root, binDir) = try planner.planTestBuild(make: &make)
+            #expect(binDir.description == "$OUTPUT/bin")
+            return root
+        }
+    }
+}
diff --git a/Plugins/PackageToJS/Tests/SnapshotTesting.swift b/Plugins/PackageToJS/Tests/SnapshotTesting.swift
new file mode 100644
index 000000000..8e556357b
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/SnapshotTesting.swift
@@ -0,0 +1,34 @@
+import Testing
+import Foundation
+
+func assertSnapshot(
+    filePath: String = #filePath, function: String = #function,
+    sourceLocation: SourceLocation = #_sourceLocation,
+    variant: String? = nil,
+    input: Data
+) throws {
+    let testFileName = URL(fileURLWithPath: filePath).deletingPathExtension().lastPathComponent
+    let snapshotDir = URL(fileURLWithPath: filePath)
+        .deletingLastPathComponent()
+        .appendingPathComponent("__Snapshots__")
+        .appendingPathComponent(testFileName)
+    try FileManager.default.createDirectory(at: snapshotDir, withIntermediateDirectories: true)
+    let snapshotFileName: String = "\(function[..<function.firstIndex(of: "(")!])\(variant.map { "_\($0)" } ?? "").json"
+    let snapshotPath = snapshotDir.appendingPathComponent(snapshotFileName)
+
+    if FileManager.default.fileExists(atPath: snapshotPath.path) {
+        let existingSnapshot = try String(contentsOf: snapshotPath, encoding: .utf8)
+        let ok = existingSnapshot == String(data: input, encoding: .utf8)!
+        let actualFilePath = snapshotPath.path + ".actual"
+        func buildComment() -> Comment {
+            "Snapshot mismatch: \(actualFilePath) \(snapshotPath.path)"
+        }
+        if !ok {
+            try input.write(to: URL(fileURLWithPath: actualFilePath))
+        }
+        #expect(ok, buildComment(), sourceLocation: sourceLocation)
+    } else {
+        try input.write(to: snapshotPath)
+        #expect(Bool(false), "Snapshot created at \(snapshotPath.path)", sourceLocation: sourceLocation)
+    }
+}
diff --git a/Plugins/PackageToJS/Tests/TemporaryDirectory.swift b/Plugins/PackageToJS/Tests/TemporaryDirectory.swift
index 4aa543bbf..199380fac 100644
--- a/Plugins/PackageToJS/Tests/TemporaryDirectory.swift
+++ b/Plugins/PackageToJS/Tests/TemporaryDirectory.swift
@@ -4,7 +4,7 @@ struct MakeTemporaryDirectoryError: Error {
     let error: CInt
 }
 
-internal func withTemporaryDirectory<T>(body: (URL) throws -> T) throws -> T {
+internal func withTemporaryDirectory<T>(body: (URL, _ retain: inout Bool) throws -> T) throws -> T {
     // Create a temporary directory using mkdtemp
     var template = FileManager.default.temporaryDirectory.appendingPathComponent("PackageToJSTests.XXXXXX").path
     return try template.withUTF8 { template in
@@ -16,9 +16,12 @@ internal func withTemporaryDirectory<T>(body: (URL) throws -> T) throws -> T {
             throw MakeTemporaryDirectoryError(error: errno)
         }
         let tempDir = URL(fileURLWithPath: String(cString: result))
+        var retain = false
         defer {
-            try? FileManager.default.removeItem(at: tempDir)
+            if !retain {
+                try? FileManager.default.removeItem(at: tempDir)
+            }
         }
-        return try body(tempDir)
+        return try body(tempDir, &retain)
     }
-}
\ No newline at end of file
+}
diff --git a/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_debug.json b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_debug.json
new file mode 100644
index 000000000..0b1b2ac80
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_debug.json
@@ -0,0 +1,275 @@
+[
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$INTERMEDIATES",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm"
+    ],
+    "output" : "$INTERMEDIATES\/wasm-imports.json",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES",
+      "$OUTPUT\/main.wasm"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$WASM_PRODUCT_ARTIFACT"
+    ],
+    "output" : "$OUTPUT\/main.wasm",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/package.json"
+    ],
+    "output" : "$OUTPUT\/package.json",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/platforms",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.worker.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.worker.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Sources\/JavaScriptKit\/Runtime\/index.mjs",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/runtime.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+      "phony",
+      "silent"
+    ],
+    "inputs" : [
+
+    ],
+    "output" : "all",
+    "wants" : [
+      "$OUTPUT\/main.wasm",
+      "$INTERMEDIATES\/wasm-imports.json",
+      "$OUTPUT\/package.json",
+      "$OUTPUT\/index.js",
+      "$OUTPUT\/index.d.ts",
+      "$OUTPUT\/instantiate.js",
+      "$OUTPUT\/instantiate.d.ts",
+      "$OUTPUT\/platforms\/browser.js",
+      "$OUTPUT\/platforms\/browser.d.ts",
+      "$OUTPUT\/platforms\/browser.worker.js",
+      "$OUTPUT\/platforms\/node.js",
+      "$OUTPUT\/platforms\/node.d.ts",
+      "$OUTPUT\/runtime.js"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release.json b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release.json
new file mode 100644
index 000000000..bb2c3f74b
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release.json
@@ -0,0 +1,290 @@
+[
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$INTERMEDIATES",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$WASM_PRODUCT_ARTIFACT"
+    ],
+    "output" : "$INTERMEDIATES\/main.wasm.debug",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm"
+    ],
+    "output" : "$INTERMEDIATES\/wasm-imports.json",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES",
+      "$OUTPUT\/main.wasm"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$INTERMEDIATES\/main.wasm.debug"
+    ],
+    "output" : "$OUTPUT\/main.wasm",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES\/main.wasm.debug"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/package.json"
+    ],
+    "output" : "$OUTPUT\/package.json",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/platforms",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.worker.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.worker.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Sources\/JavaScriptKit\/Runtime\/index.mjs",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/runtime.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+      "phony",
+      "silent"
+    ],
+    "inputs" : [
+
+    ],
+    "output" : "all",
+    "wants" : [
+      "$OUTPUT\/main.wasm",
+      "$INTERMEDIATES\/wasm-imports.json",
+      "$OUTPUT\/package.json",
+      "$OUTPUT\/index.js",
+      "$OUTPUT\/index.d.ts",
+      "$OUTPUT\/instantiate.js",
+      "$OUTPUT\/instantiate.d.ts",
+      "$OUTPUT\/platforms\/browser.js",
+      "$OUTPUT\/platforms\/browser.d.ts",
+      "$OUTPUT\/platforms\/browser.worker.js",
+      "$OUTPUT\/platforms\/node.js",
+      "$OUTPUT\/platforms\/node.d.ts",
+      "$OUTPUT\/runtime.js"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_no_optimize.json b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_no_optimize.json
new file mode 100644
index 000000000..0b1b2ac80
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_no_optimize.json
@@ -0,0 +1,275 @@
+[
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$INTERMEDIATES",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm"
+    ],
+    "output" : "$INTERMEDIATES\/wasm-imports.json",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES",
+      "$OUTPUT\/main.wasm"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$WASM_PRODUCT_ARTIFACT"
+    ],
+    "output" : "$OUTPUT\/main.wasm",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/package.json"
+    ],
+    "output" : "$OUTPUT\/package.json",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/platforms",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.worker.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.worker.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Sources\/JavaScriptKit\/Runtime\/index.mjs",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/runtime.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+      "phony",
+      "silent"
+    ],
+    "inputs" : [
+
+    ],
+    "output" : "all",
+    "wants" : [
+      "$OUTPUT\/main.wasm",
+      "$INTERMEDIATES\/wasm-imports.json",
+      "$OUTPUT\/package.json",
+      "$OUTPUT\/index.js",
+      "$OUTPUT\/index.d.ts",
+      "$OUTPUT\/instantiate.js",
+      "$OUTPUT\/instantiate.d.ts",
+      "$OUTPUT\/platforms\/browser.js",
+      "$OUTPUT\/platforms\/browser.d.ts",
+      "$OUTPUT\/platforms\/browser.worker.js",
+      "$OUTPUT\/platforms\/node.js",
+      "$OUTPUT\/platforms\/node.d.ts",
+      "$OUTPUT\/runtime.js"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_split_debug.json b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_split_debug.json
new file mode 100644
index 000000000..b18680f8d
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planBuild_release_split_debug.json
@@ -0,0 +1,290 @@
+[
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$INTERMEDIATES",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm"
+    ],
+    "output" : "$INTERMEDIATES\/wasm-imports.json",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES",
+      "$OUTPUT\/main.wasm"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm.debug"
+    ],
+    "output" : "$OUTPUT\/main.wasm",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/main.wasm.debug"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$WASM_PRODUCT_ARTIFACT"
+    ],
+    "output" : "$OUTPUT\/main.wasm.debug",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/package.json"
+    ],
+    "output" : "$OUTPUT\/package.json",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/platforms",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.worker.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.worker.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Sources\/JavaScriptKit\/Runtime\/index.mjs",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/runtime.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+      "phony",
+      "silent"
+    ],
+    "inputs" : [
+
+    ],
+    "output" : "all",
+    "wants" : [
+      "$OUTPUT\/main.wasm",
+      "$INTERMEDIATES\/wasm-imports.json",
+      "$OUTPUT\/package.json",
+      "$OUTPUT\/index.js",
+      "$OUTPUT\/index.d.ts",
+      "$OUTPUT\/instantiate.js",
+      "$OUTPUT\/instantiate.d.ts",
+      "$OUTPUT\/platforms\/browser.js",
+      "$OUTPUT\/platforms\/browser.d.ts",
+      "$OUTPUT\/platforms\/browser.worker.js",
+      "$OUTPUT\/platforms\/node.js",
+      "$OUTPUT\/platforms\/node.d.ts",
+      "$OUTPUT\/runtime.js"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planTestBuild.json b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planTestBuild.json
new file mode 100644
index 000000000..59e5bb4ad
--- /dev/null
+++ b/Plugins/PackageToJS/Tests/__Snapshots__/PackagingPlannerTests/planTestBuild.json
@@ -0,0 +1,367 @@
+[
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$INTERMEDIATES",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/package.json"
+    ],
+    "output" : "$INTERMEDIATES\/npm-install.stamp",
+    "wants" : [
+      "$INTERMEDIATES",
+      "$OUTPUT\/package.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$OUTPUT\/main.wasm"
+    ],
+    "output" : "$INTERMEDIATES\/wasm-imports.json",
+    "wants" : [
+      "$OUTPUT",
+      "$INTERMEDIATES",
+      "$OUTPUT\/main.wasm"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/bin",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/bin\/test.js"
+    ],
+    "output" : "$OUTPUT\/bin\/test.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/bin"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/index.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/index.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/instantiate.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/instantiate.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$WASM_PRODUCT_ARTIFACT"
+    ],
+    "output" : "$OUTPUT\/main.wasm",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/package.json"
+    ],
+    "output" : "$OUTPUT\/package.json",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT"
+    ]
+  },
+  {
+    "attributes" : [
+      "silent"
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH"
+    ],
+    "output" : "$OUTPUT\/platforms",
+    "wants" : [
+
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/browser.worker.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/browser.worker.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.d.ts",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/platforms\/node.js",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/platforms\/node.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Sources\/JavaScriptKit\/Runtime\/index.mjs",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ],
+    "output" : "$OUTPUT\/runtime.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/platforms",
+      "$INTERMEDIATES\/wasm-imports.json"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/test.browser.html"
+    ],
+    "output" : "$OUTPUT\/test.browser.html",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/bin"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/test.d.ts"
+    ],
+    "output" : "$OUTPUT\/test.d.ts",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/bin"
+    ]
+  },
+  {
+    "attributes" : [
+
+    ],
+    "inputs" : [
+      "$PLANNER_SOURCE_PATH",
+      "$SELF_PACKAGE\/Plugins\/PackageToJS\/Templates\/test.js"
+    ],
+    "output" : "$OUTPUT\/test.js",
+    "salt" : "eyJjb25kaXRpb25zIjp7IklTX1dBU0kiOnRydWUsIlVTRV9TSEFSRURfTUVNT1JZIjpmYWxzZSwiVVNFX1dBU0lfQ0ROIjpmYWxzZX0sInN1YnN0aXR1dGlvbnMiOnsiUEFDS0FHRV9UT19KU19NT0RVTEVfUEFUSCI6Im1haW4ud2FzbSIsIlBBQ0tBR0VfVE9fSlNfUEFDS0FHRV9OQU1FIjoidGVzdCJ9fQ==",
+    "wants" : [
+      "$OUTPUT",
+      "$OUTPUT\/bin"
+    ]
+  },
+  {
+    "attributes" : [
+      "phony",
+      "silent"
+    ],
+    "inputs" : [
+
+    ],
+    "output" : "all",
+    "wants" : [
+      "$OUTPUT\/main.wasm",
+      "$INTERMEDIATES\/wasm-imports.json",
+      "$OUTPUT\/package.json",
+      "$OUTPUT\/index.js",
+      "$OUTPUT\/index.d.ts",
+      "$OUTPUT\/instantiate.js",
+      "$OUTPUT\/instantiate.d.ts",
+      "$OUTPUT\/platforms\/browser.js",
+      "$OUTPUT\/platforms\/browser.d.ts",
+      "$OUTPUT\/platforms\/browser.worker.js",
+      "$OUTPUT\/platforms\/node.js",
+      "$OUTPUT\/platforms\/node.d.ts",
+      "$OUTPUT\/runtime.js",
+      "$INTERMEDIATES\/npm-install.stamp",
+      "$OUTPUT\/bin",
+      "$OUTPUT\/test.js",
+      "$OUTPUT\/test.d.ts",
+      "$OUTPUT\/test.browser.html",
+      "$OUTPUT\/bin\/test.js"
+    ]
+  }
+]
\ No newline at end of file
diff --git a/Tests/JavaScriptEventLoopTests/JavaScriptEventLoopTests.swift b/Tests/JavaScriptEventLoopTests/JavaScriptEventLoopTests.swift
index 029876904..5d610aa48 100644
--- a/Tests/JavaScriptEventLoopTests/JavaScriptEventLoopTests.swift
+++ b/Tests/JavaScriptEventLoopTests/JavaScriptEventLoopTests.swift
@@ -197,7 +197,7 @@ final class JavaScriptEventLoopTests: XCTestCase {
             let result = try await catchPromise2.value
             XCTAssertEqual(result.object?.message, .string("test"))
         }
-        XCTAssertGreaterThanOrEqual(catchDiff, 200)
+        XCTAssertGreaterThanOrEqual(catchDiff, 150)
     }
 
     // MARK: - Continuation Tests
diff --git a/package-lock.json b/package-lock.json
index 18415649f..bb5718d1b 100644
--- a/package-lock.json
+++ b/package-lock.json
@@ -10,6 +10,7 @@
       "license": "MIT",
       "devDependencies": {
         "@rollup/plugin-typescript": "^8.3.1",
+        "playwright": "^1.51.0",
         "prettier": "2.6.1",
         "rollup": "^2.70.0",
         "tslib": "^2.3.1",
@@ -125,6 +126,38 @@
         "url": "https://github.com/sponsors/jonschlinkert"
       }
     },
+    "node_modules/playwright": {
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.51.0.tgz",
+      "integrity": "sha512-442pTfGM0xxfCYxuBa/Pu6B2OqxqqaYq39JS8QDMGThUvIOCd6s0ANDog3uwA0cHavVlnTQzGCN7Id2YekDSXA==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "dependencies": {
+        "playwright-core": "1.51.0"
+      },
+      "bin": {
+        "playwright": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      },
+      "optionalDependencies": {
+        "fsevents": "2.3.2"
+      }
+    },
+    "node_modules/playwright-core": {
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.51.0.tgz",
+      "integrity": "sha512-x47yPE3Zwhlil7wlNU/iktF7t2r/URR3VLbH6EknJd/04Qc/PSJ0EY3CMXipmglLG+zyRxW6HNo2EGbKLHPWMg==",
+      "dev": true,
+      "license": "Apache-2.0",
+      "bin": {
+        "playwright-core": "cli.js"
+      },
+      "engines": {
+        "node": ">=18"
+      }
+    },
     "node_modules/prettier": {
       "version": "2.6.1",
       "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.6.1.tgz",
@@ -281,6 +314,22 @@
       "integrity": "sha512-JU3teHTNjmE2VCGFzuY8EXzCDVwEqB2a8fsIvwaStHhAWJEeVd1o1QD80CU6+ZdEXXSLbSsuLwJjkCBWqRQUVA==",
       "dev": true
     },
+    "playwright": {
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/playwright/-/playwright-1.51.0.tgz",
+      "integrity": "sha512-442pTfGM0xxfCYxuBa/Pu6B2OqxqqaYq39JS8QDMGThUvIOCd6s0ANDog3uwA0cHavVlnTQzGCN7Id2YekDSXA==",
+      "dev": true,
+      "requires": {
+        "fsevents": "2.3.2",
+        "playwright-core": "1.51.0"
+      }
+    },
+    "playwright-core": {
+      "version": "1.51.0",
+      "resolved": "https://registry.npmjs.org/playwright-core/-/playwright-core-1.51.0.tgz",
+      "integrity": "sha512-x47yPE3Zwhlil7wlNU/iktF7t2r/URR3VLbH6EknJd/04Qc/PSJ0EY3CMXipmglLG+zyRxW6HNo2EGbKLHPWMg==",
+      "dev": true
+    },
     "prettier": {
       "version": "2.6.1",
       "resolved": "https://registry.npmjs.org/prettier/-/prettier-2.6.1.tgz",
diff --git a/package.json b/package.json
index e25d0a17b..0c67b2705 100644
--- a/package.json
+++ b/package.json
@@ -35,6 +35,7 @@
   "license": "MIT",
   "devDependencies": {
     "@rollup/plugin-typescript": "^8.3.1",
+    "playwright": "^1.51.0",
     "prettier": "2.6.1",
     "rollup": "^2.70.0",
     "tslib": "^2.3.1",