alternative for addressing test issues

jest.config.js

@@ -11,6 +11,7 @@ module.exports = {
     '@stencil/core/mock-doc': '<rootDir>/mock-doc/index.cjs',
     '@stencil/core/testing': '<rootDir>/testing/index.js',
     '@utils': '<rootDir>/src/utils',
+    '^typescript$': '<rootDir>/scripts/build/typescript-modified-for-jest.js',
   },
   coverageDirectory: './coverage/',
   coverageReporters: ['json', 'lcov', 'text', 'clover'],

scripts/bundles/plugins/typescript-source-plugin.ts

@@ -122,6 +122,9 @@ async function bundleTypeScriptSource(tsPath: string, opts: BuildOptions): Promi
 
   code = code.replace(TS_PROP_DEFINER, TS_PROP_DEFINER_RECONFIGURABLE);
 
+  const jestTypesciptFilename = join(opts.scriptsBuildDir, 'typescript-modified-for-jest.js');
+  await fs.writeFile(jestTypesciptFilename, code);
+
   // Here we transform the TypeScript source from a commonjs to an ES module.
   // We do this so that we can add an import from the `@environment` module.
 

src/compiler/transformers/test/map-imports-to-path-aliases.spec.ts

@@ -1,38 +1,24 @@
 import type { OutputTargetDistCollection } from '@stencil/core/declarations';
 import { mockValidatedConfig } from '@stencil/core/testing';
-import { Extension } from 'typescript';
-import * as ts from 'typescript';
+import ts, { Extension } from 'typescript';
 
 import { ValidatedConfig } from '../../../internal';
 import { mapImportsToPathAliases } from '../map-imports-to-path-aliases';
 import { transpileModule } from './transpile';
 
-let resolveModuleNameSpy: jest.Mock<ReturnType<typeof ts.resolveModuleName>, Parameters<typeof ts.resolveModuleName>>;
-
-// we need to mock typescript instead of being able to spy on
-// `resolveModuleName` because as of TS 5.0 the default export is an object
-// where methods are set on it using `Object.defineProperty` but they are
-// _not_ configurable. This means that `jest.spyOn` can't overwrite them with
-// a spy function!
-jest.mock('typescript', () => {
-  const original = jest.requireActual('typescript');
-  return {
-    ...original,
-    resolveModuleName: jest.fn((moduleName, containingFile, compilerOptions, moduleResolutionHost) => {
-      return resolveModuleNameSpy(moduleName, containingFile, compilerOptions, moduleResolutionHost);
-    }),
-  };
-});
-
 describe('mapImportsToPathAliases', () => {
   let module: ReturnType<typeof transpileModule>;
   let config: ValidatedConfig;
+  let resolveModuleNameSpy: jest.SpyInstance<
+    ReturnType<typeof ts.resolveModuleName>,
+    Parameters<typeof ts.resolveModuleName>
+  >;
   let outputTarget: OutputTargetDistCollection;
 
   beforeEach(() => {
     config = mockValidatedConfig({ tsCompilerOptions: {} });
 
-    resolveModuleNameSpy = jest.fn();
+    resolveModuleNameSpy = jest.spyOn(ts, 'resolveModuleName');
 
     outputTarget = {
       type: 'dist-collection',