Merge branch 'main' into fix44572

Author: ahejlsberg

Gulpfile.js

@@ -437,10 +437,6 @@ task("watch-local").flags = {
     "   --built": "Compile using the built version of the compiler."
 };
 
-const generateCodeCoverage = () => exec("istanbul", ["cover", "node_modules/mocha/bin/_mocha", "--", "-R", "min", "-t", "" + cmdLineOptions.testTimeout, "built/local/run.js"]);
-task("generate-code-coverage", series(preBuild, buildTests, generateCodeCoverage));
-task("generate-code-coverage").description = "Generates code coverage data via istanbul";
-
 const preTest = parallel(buildTsc, buildTests, buildServices, buildLssl);
 preTest.displayName = "preTest";
 

lib/lib.es2021.d.ts

@@ -22,3 +22,4 @@ and limitations under the License.
 /// <reference lib="es2021.promise" />
 /// <reference lib="es2021.string" />
 /// <reference lib="es2021.weakref" />
+/// <reference lib="es2021.intl" />

package-lock.json

@@ -79,7 +79,6 @@
         "gulp-newer": "latest",
         "gulp-rename": "latest",
         "gulp-sourcemaps": "latest",
-        "istanbul": "latest",
         "merge2": "latest",
         "minimist": "latest",
         "mkdirp": "latest",

package.json

@@ -3388,7 +3388,7 @@ namespace ts {
 
         function bindTypeParameter(node: TypeParameterDeclaration) {
             if (isJSDocTemplateTag(node.parent)) {
-                const container = find((node.parent.parent as JSDoc).tags!, isJSDocTypeAlias) || getHostSignatureFromJSDoc(node.parent); // TODO: GH#18217
+                const container = getEffectiveContainerForJSDocTemplateTag(node.parent);
                 if (container) {
                     if (!container.locals) {
                         container.locals = createSymbolTable();

src/compiler/binder.ts

@@ -71,6 +71,7 @@ namespace ts {
         ["es2021.promise", "lib.es2021.promise.d.ts"],
         ["es2021.string", "lib.es2021.string.d.ts"],
         ["es2021.weakref", "lib.es2021.weakref.d.ts"],
+        ["es2021.intl", "lib.es2021.intl.d.ts"],
         ["esnext.array", "lib.es2019.array.d.ts"],
         ["esnext.symbol", "lib.es2019.symbol.d.ts"],
         ["esnext.asynciterable", "lib.es2018.asynciterable.d.ts"],
@@ -570,7 +571,7 @@ namespace ts {
             type: new Map(getEntries({
                 remove: ImportsNotUsedAsValues.Remove,
                 preserve: ImportsNotUsedAsValues.Preserve,
-                error: ImportsNotUsedAsValues.Error
+                error: ImportsNotUsedAsValues.Error,
             })),
             affectsEmit: true,
             affectsSemanticDiagnostics: true,
@@ -1166,8 +1167,16 @@ namespace ts {
             affectsEmit: true,
             category: Diagnostics.Language_and_Environment,
             description: Diagnostics.Emit_ECMAScript_standard_compliant_class_fields,
-            defaultValueDescription: "false"
+            defaultValueDescription: Diagnostics.true_for_ES2022_and_above_including_ESNext
+        },
+        {
+            name: "preserveValueImports",
+            type: "boolean",
+            affectsEmit: true,
+            category: Diagnostics.Emit,
+            description: Diagnostics.Preserve_unused_imported_values_in_the_JavaScript_output_that_would_otherwise_be_removed,
         },
+
         {
             name: "keyofStringsOnly",
             type: "boolean",
@@ -2852,6 +2861,7 @@ namespace ts {
         let typeAcquisition: TypeAcquisition | undefined, typingOptionstypeAcquisition: TypeAcquisition | undefined;
         let watchOptions: WatchOptions | undefined;
         let extendedConfigPath: string | undefined;
+        let rootCompilerOptions: PropertyName[] | undefined;
 
         const optionsIterator: JsonConversionNotifier = {
             onSetValidOptionKeyValueInParent(parentOption: string, option: CommandLineOption, value: CompilerOptionsValue) {
@@ -2894,6 +2904,9 @@ namespace ts {
                 if (key === "excludes") {
                     errors.push(createDiagnosticForNodeInSourceFile(sourceFile, keyNode, Diagnostics.Unknown_option_excludes_Did_you_mean_exclude));
                 }
+                if (find(commandOptionsWithoutBuild, (opt) => opt.name === key)) {
+                    rootCompilerOptions = append(rootCompilerOptions, keyNode);
+                }
             }
         };
         const json = convertConfigFileToObject(sourceFile, errors, /*reportOptionsErrors*/ true, optionsIterator);
@@ -2913,6 +2926,10 @@ namespace ts {
             }
         }
 
+        if (rootCompilerOptions && json && json.compilerOptions === undefined) {
+            errors.push(createDiagnosticForNodeInSourceFile(sourceFile, rootCompilerOptions[0], Diagnostics._0_should_be_set_inside_the_compilerOptions_object_of_the_config_json_file, getTextOfPropertyName(rootCompilerOptions[0]) as string));
+        }
+
         return { raw: json, options, watchOptions, typeAcquisition, extendedConfigPath };
     }
 

src/compiler/checker.ts

@@ -1372,6 +1372,22 @@
         "category": "Error",
         "code": 1443
     },
+    "'{0}' is a type and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.": {
+        "category": "Error",
+        "code": 1444
+    },
+    "'{0}' resolves to a type-only declaration and must be imported using a type-only import when 'preserveValueImports' and 'isolatedModules' are both enabled.": {
+        "category": "Error",
+        "code": 1446
+    },
+    "'{0}' resolves to a type-only declaration and must be re-exported using a type-only re-export when 'isolatedModules' is enabled.": {
+        "category": "Error",
+        "code": 1448
+    },
+    "Preserve unused imported values in the JavaScript output that would otherwise be removed.": {
+        "category": "Message",
+        "code": 1449
+    },
 
     "The types of '{0}' are incompatible between these types.": {
         "category": "Error",
@@ -3910,6 +3926,10 @@
         "category": "Error",
         "code": 5094
     },
+    "Option 'preserveValueImports' can only be used when 'module' is set to 'es2015' or later.": {
+        "category": "Error",
+        "code": 5095
+    },
 
     "Generates a sourcemap for each corresponding '.d.ts' file.": {
         "category": "Message",
@@ -4834,6 +4854,10 @@
         "category": "Message",
         "code": 6257
     },
+    "'{0}' should be set inside the 'compilerOptions' object of the config json file": {
+        "category": "Error",
+        "code": 6258
+    },
 
     "Enable project compilation": {
         "category": "Message",
@@ -5668,6 +5692,11 @@
         "category": "Message",
         "code": 6929
     },
+    "`true` for ES2022 and above, including ESNext.": {
+        "category": "Message",
+        "code": 6930
+    },
+
 
     "Variable '{0}' implicitly has an '{1}' type.": {
         "category": "Error",

src/compiler/commandLineParser.ts

@@ -4939,14 +4939,16 @@ namespace ts {
         }
 
         // @api
-        function createCatchClause(variableDeclaration: string | VariableDeclaration | undefined, block: Block) {
+        function createCatchClause(variableDeclaration: string | BindingName | VariableDeclaration | undefined, block: Block) {
             const node = createBaseNode<CatchClause>(SyntaxKind.CatchClause);
-            variableDeclaration = !isString(variableDeclaration) ? variableDeclaration : createVariableDeclaration(
-                variableDeclaration,
-                /*exclamationToken*/ undefined,
-                /*type*/ undefined,
-                /*initializer*/ undefined
-            );
+            if (typeof variableDeclaration === "string" || variableDeclaration && !isVariableDeclaration(variableDeclaration)) {
+                variableDeclaration = createVariableDeclaration(
+                    variableDeclaration,
+                    /*exclamationToken*/ undefined,
+                    /*type*/ undefined,
+                    /*initializer*/ undefined
+                );
+            }
             node.variableDeclaration = variableDeclaration;
             node.block = block;
             node.transformFlags |=

src/compiler/diagnosticMessages.json

@@ -8441,11 +8441,24 @@ namespace ts {
 
                 function parseTemplateTagTypeParameter() {
                     const typeParameterPos = getNodePos();
+                    const isBracketed = parseOptionalJsdoc(SyntaxKind.OpenBracketToken);
+                    if (isBracketed) {
+                        skipWhitespace();
+                    }
                     const name = parseJSDocIdentifierName(Diagnostics.Unexpected_token_A_type_parameter_name_was_expected_without_curly_braces);
+
+                    let defaultType: TypeNode | undefined;
+                    if (isBracketed) {
+                        skipWhitespace();
+                        parseExpected(SyntaxKind.EqualsToken);
+                        defaultType = doInsideOfContext(NodeFlags.JSDoc, parseJSDocType);
+                        parseExpected(SyntaxKind.CloseBracketToken);
+                    }
+
                     if (nodeIsMissing(name)) {
                         return undefined;
                     }
-                    return finishNode(factory.createTypeParameterDeclaration(name, /*constraint*/ undefined, /*defaultType*/ undefined), typeParameterPos);
+                    return finishNode(factory.createTypeParameterDeclaration(name, /*constraint*/ undefined, defaultType), typeParameterPos);
                 }
 
                 function parseTemplateTagTypeParameters() {

src/compiler/factory/nodeFactory.ts

@@ -3305,6 +3305,10 @@ namespace ts {
                 }
             }
 
+            if (options.preserveValueImports && getEmitModuleKind(options) < ModuleKind.ES2015) {
+                createOptionValueDiagnostic("importsNotUsedAsValues", Diagnostics.Option_preserveValueImports_can_only_be_used_when_module_is_set_to_es2015_or_later);
+            }
+
             // If the emit is enabled make sure that every output file is unique and not overwriting any of the input files
             if (!options.noEmit && !options.suppressOutputPathCheck) {
                 const emitHost = getEmitHost();
@@ -3575,7 +3579,7 @@ namespace ts {
             createDiagnosticForOption(/*onKey*/ true, option1, option2, message, option1, option2, option3);
         }
 
-        function createOptionValueDiagnostic(option1: string, message: DiagnosticMessage, arg0: string) {
+        function createOptionValueDiagnostic(option1: string, message: DiagnosticMessage, arg0?: string) {
             createDiagnosticForOption(/*onKey*/ false, option1, /*option2*/ undefined, message, arg0);
         }
 
@@ -3590,7 +3594,7 @@ namespace ts {
             }
         }
 
-        function createDiagnosticForOption(onKey: boolean, option1: string, option2: string | undefined, message: DiagnosticMessage, arg0: string | number, arg1?: string | number, arg2?: string | number) {
+        function createDiagnosticForOption(onKey: boolean, option1: string, option2: string | undefined, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number) {
             const compilerOptionsObjectLiteralSyntax = getCompilerOptionsObjectLiteralSyntax();
             const needCompilerDiagnostic = !compilerOptionsObjectLiteralSyntax ||
                 !createOptionDiagnosticInObjectLiteralSyntax(compilerOptionsObjectLiteralSyntax, onKey, option1, option2, message, arg0, arg1, arg2);
@@ -3616,7 +3620,7 @@ namespace ts {
             return _compilerOptionsObjectLiteralSyntax || undefined;
         }
 
-        function createOptionDiagnosticInObjectLiteralSyntax(objectLiteral: ObjectLiteralExpression, onKey: boolean, key1: string, key2: string | undefined, message: DiagnosticMessage, arg0: string | number, arg1?: string | number, arg2?: string | number): boolean {
+        function createOptionDiagnosticInObjectLiteralSyntax(objectLiteral: ObjectLiteralExpression, onKey: boolean, key1: string, key2: string | undefined, message: DiagnosticMessage, arg0?: string | number, arg1?: string | number, arg2?: string | number): boolean {
             const props = getPropertyAssignment(objectLiteral, key1, key2);
             for (const prop of props) {
                 programDiagnostics.add(createDiagnosticForNodeInSourceFile(options.configFile!, onKey ? prop.name : prop.initializer, message, arg0, arg1, arg2));

src/compiler/parser.ts

@@ -2791,7 +2791,7 @@ namespace ts {
         }
 
         /**
-         * Visits an import declaration, eliding it if it is not referenced and `importsNotUsedAsValues` is not 'preserve'.
+         * Visits an import declaration, eliding it if it is type-only or if it has an import clause that may be elided.
          *
          * @param node The import declaration node.
          */
@@ -2821,29 +2821,27 @@ namespace ts {
         }
 
         /**
-         * Visits an import clause, eliding it if it is not referenced.
+         * Visits an import clause, eliding it if its `name` and `namedBindings` may both be elided.
          *
          * @param node The import clause node.
          */
         function visitImportClause(node: ImportClause): VisitResult<ImportClause> {
-            if (node.isTypeOnly) {
-                return undefined;
-            }
+            Debug.assert(!node.isTypeOnly);
             // Elide the import clause if we elide both its name and its named bindings.
-            const name = resolver.isReferencedAliasDeclaration(node) ? node.name : undefined;
+            const name = shouldEmitAliasDeclaration(node) ? node.name : undefined;
             const namedBindings = visitNode(node.namedBindings, visitNamedImportBindings, isNamedImportBindings);
             return (name || namedBindings) ? factory.updateImportClause(node, /*isTypeOnly*/ false, name, namedBindings) : undefined;
         }
 
         /**
-         * Visits named import bindings, eliding it if it is not referenced.
+         * Visits named import bindings, eliding them if their targets, their references, and the compilation settings allow.
          *
          * @param node The named import bindings node.
          */
         function visitNamedImportBindings(node: NamedImportBindings): VisitResult<NamedImportBindings> {
             if (node.kind === SyntaxKind.NamespaceImport) {
                 // Elide a namespace import if it is not referenced.
-                return resolver.isReferencedAliasDeclaration(node) ? node : undefined;
+                return shouldEmitAliasDeclaration(node) ? node : undefined;
             }
             else {
                 // Elide named imports if all of its import specifiers are elided.
@@ -2853,13 +2851,12 @@ namespace ts {
         }
 
         /**
-         * Visits an import specifier, eliding it if it is not referenced.
+         * Visits an import specifier, eliding it if its target, its references, and the compilation settings allow.
          *
          * @param node The import specifier node.
          */
         function visitImportSpecifier(node: ImportSpecifier): VisitResult<ImportSpecifier> {
-            // Elide an import specifier if it is not referenced.
-            return resolver.isReferencedAliasDeclaration(node) ? node : undefined;
+            return shouldEmitAliasDeclaration(node) ? node : undefined;
         }
 
         /**
@@ -2876,8 +2873,7 @@ namespace ts {
         }
 
         /**
-         * Visits an export declaration, eliding it if it does not contain a clause that resolves
-         * to a value.
+         * Visits an export declaration, eliding it if it does not contain a clause that resolves to a value.
          *
          * @param node The export declaration node.
          */
@@ -2950,7 +2946,7 @@ namespace ts {
             // preserve old compiler's behavior: emit 'var' for import declaration (even if we do not consider them referenced) when
             // - current file is not external module
             // - import declaration is top level and target is value imported by entity name
-            return resolver.isReferencedAliasDeclaration(node)
+            return shouldEmitAliasDeclaration(node)
                 || (!isExternalModule(currentSourceFile)
                     && resolver.isTopLevelValueImportEqualsWithEntityName(node));
         }
@@ -2967,7 +2963,7 @@ namespace ts {
             }
 
             if (isExternalModuleImportEqualsDeclaration(node)) {
-                const isReferenced = resolver.isReferencedAliasDeclaration(node);
+                const isReferenced = shouldEmitAliasDeclaration(node);
                 // If the alias is unreferenced but we want to keep the import, replace with 'import "mod"'.
                 if (!isReferenced && compilerOptions.importsNotUsedAsValues === ImportsNotUsedAsValues.Preserve) {
                     return setOriginalNode(
@@ -3358,5 +3354,11 @@ namespace ts {
 
             return isPropertyAccessExpression(node) || isElementAccessExpression(node) ? resolver.getConstantValue(node) : undefined;
         }
+
+        function shouldEmitAliasDeclaration(node: Node): boolean {
+            return compilerOptions.preserveValueImports
+                ? resolver.isValueAliasDeclaration(node)
+                : resolver.isReferencedAliasDeclaration(node);
+        }
     }
 }