feat: support custom codec files in host repositories

DX-658

Author: ad-world

packages/openapi-generator/src/project.ts

@@ -37,6 +37,7 @@ export class Project {
   async parseEntryPoint(entryPoint: string): Promise<E.Either<string, Project>> {
     const queue: string[] = [entryPoint];
     let path: string | undefined;
+    const visitedPackages = new Set<string>();
     while (((path = queue.pop()), path !== undefined)) {
       if (!['.ts', '.js'].includes(p.extname(path))) {
         continue;
@@ -59,6 +60,14 @@ export class Project {
           // If we are not resolving a relative path, we need to resolve the entry point
           const baseDir = p.dirname(sourceFile.path);
           let entryPoint = this.resolveEntryPoint(baseDir, sym.from);
+
+          if (!visitedPackages.has(sym.from)) {
+            // This is a step that checks if this import has custom codecs, and loads them into known imports
+            await this.populateCustomCodecs(baseDir, sym.from);
+          }
+
+          visitedPackages.add(sym.from);
+
           if (E.isLeft(entryPoint)) {
             continue;
           } else if (!this.has(entryPoint.right)) {
@@ -148,4 +157,40 @@ export class Project {
   getTypes() {
     return this.types;
   }
+
+  private async populateCustomCodecs(basedir: string, packageName: string) {
+    try {
+      const packageJson = resolve.sync(`${packageName}/package.json`, {
+        basedir,
+        extensions: ['.json'],
+      });
+      const packageInfo = JSON.parse(fs.readFileSync(packageJson, 'utf8'));
+
+      if (packageInfo['customCodecFile']) {
+        // The package defines their own custom codecs
+        const customCodecPath = resolve.sync(
+          `${packageName}/${packageInfo['customCodecFile']}`,
+          {
+            basedir,
+            extensions: ['.ts', '.js'],
+          },
+        );
+        const module = await import(customCodecPath);
+        if (module.default === undefined) {
+          console.error(`Could not find default export in ${customCodecPath}`);
+          return;
+        }
+
+        const customCodecs = module.default(E);
+        this.knownImports[packageName] = {
+          ...this.knownImports[packageName],
+          ...customCodecs,
+        };
+
+        console.error(`Loaded custom codecs for ${packageName}`);
+      }
+    } catch (e) {
+      return;
+    }
+  }
 }

packages/openapi-generator/test/externalModuleApiSpec.test.ts

@@ -126,8 +126,8 @@ async function testCase(
       components,
     );
 
-    assert.deepEqual(errors, expectedErrors);
-    assert.deepEqual(openapi, expected);
+    assert.deepStrictEqual(errors, expectedErrors); 
+    assert.deepStrictEqual(openapi, expected);
   });
 }
 
@@ -319,3 +319,48 @@ testCase(
   },
   []
 )
+
+testCase("simple api spec with custom codec", "test/sample-types/apiSpecWithCustomCodec.ts", {
+  openapi: "3.0.3",
+  info: {
+    title: "simple api spec with custom codec",
+    version: "4.7.4",
+    description: "simple api spec with custom codec"
+  },
+  paths: {
+    "/test": {
+      get: {
+        parameters: [],
+        responses: {
+          200: {
+            description: "OK",
+            content: {
+              'application/json': {
+                schema: {
+                  type: 'string',
+                  description: 'Sample custom codec',
+                  example: 'sample',
+                  format: 'sample'
+                }
+              }
+            }
+          },
+          201: {
+            description: 'Created',
+            content: {
+              'application/json': {
+                schema: {
+                  type: 'number',
+                  description: 'Another sample codec',
+                }
+              }
+            }
+          }
+        }
+      }
+    }
+  },
+  components: {
+    schemas: {}
+  }
+}, []);

packages/openapi-generator/test/sample-types/apiSpecWithCustomCodec.ts

@@ -0,0 +1,16 @@
+import { SampleCustomCodec, AnotherSampleCodec } from '@bitgo/custom-codecs';
+import * as h from '@api-ts/io-ts-http';
+
+export const apiSpec = h.apiSpec({
+    'api.get.test': {
+        get: h.httpRoute({
+            path: '/test',
+            method: 'GET',
+            request: h.httpRequest({}),
+            response: {
+                200: SampleCustomCodec,
+                201: AnotherSampleCodec,
+            },
+        }),
+    },
+})