build: include cdk testing entry-point in release output (#17030)

Author: devversion

src/cdk/testing/tsconfig-build.json

@@ -0,0 +1,15 @@
+{
+  "extends": "../tsconfig-build",
+  "files": [
+    "public-api.ts",
+    "../typings.d.ts"
+  ],
+  "angularCompilerOptions": {
+    "annotateForClosureCompiler": true,
+    "strictMetadataEmit": true,
+    "flatModuleOutFile": "index.js",
+    "flatModuleId": "@angular/cdk/testing",
+    "skipTemplateCodegen": true,
+    "fullTemplateTypeCheck": true
+  }
+}

src/cdk/tsconfig-tests.json

@@ -14,7 +14,6 @@
     }
   },
   "files": [
-    "./testing/index.ts",
     "./index.ts",
     "typings.d.ts"
   ],
@@ -24,20 +23,25 @@
     "emitDecoratorMetadata": true,
     "fullTemplateTypeCheck": true,
 
-    // Unset options inherited from tsconfig-build
+    // Unset options inherited from tsconfig-build.
     "annotateForClosureCompiler": false,
     "flatModuleOutFile": null,
     "flatModuleId": null
   },
   "include": [
-    // Include the index.ts for each secondary entry-point
+    // Include the index.ts for each secondary entry-point.
     "./*/index.ts",
+    // Include the "private/testing" internal entry-point.
+    "./private/testing/",
+    // Include all spec files of the CDK.
     "**/*.spec.ts"
   ],
   "exclude": [
     "**/schematics/**/*.ts",
-    // Exclude end-to-end tests and utilities
+    // Exclude end-to-end tests and utilities.
     "**/*.e2e.spec.ts",
-    "./testing/e2e/**"
+    // Exclude internal e2e testing utilities. These are not needed by tests
+    // which execute through gulp.
+    "./private/testing/e2e/**"
   ]
 }