test: add tests for elide imports

This also adds the option to provide addition files when using `createTypescriptContext` this is paramount for the elide imports tests as without this certain symbols won't have the full details.

Which will cause tests to be false positive and re-surface issues like #13212

Author: Alan

packages/angular_devkit/build_angular/test/browser/aot_spec_large.ts

@@ -30,113 +30,4 @@ describe('Browser Builder AOT', () => {
       }),
     ).toPromise().then(done, done.fail);
   });
-
-  it('works with aliased imports', (done) => {
-    const overrides = { aot: true };
-
-    host.writeMultipleFiles({
-      'src/app/app.component.ts': `import { Component } from '@angular/core';
-       import { from as fromPromise } from 'rxjs';
-
-       @Component({
-         selector: 'app-root',
-         templateUrl: './app.component.html',
-         styleUrls: ['./app.component.css']
-       })
-       export class AppComponent {
-         title = 'app-component';
-
-         constructor() {
-           console.log(fromPromise(Promise.resolve('test')));
-         }
-       }`,
-    });
-
-    runTargetSpec(host, browserTargetSpec, overrides).pipe(
-      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
-      tap(() => {
-        const fileName = join(outputPath, 'main.js');
-        const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
-        // if the aliased import was dropped this won't be rewired to a webpack module.
-        expect(content).toMatch(/rxjs__WEBPACK_IMPORTED_.+[\"from\"]/);
-        expect(content).not.toContain('fromPromise');
-      }),
-    ).toPromise().then(done, done.fail);
-  });
-
-  it('works with aliased imports from an exported object literal', (done) => {
-    const overrides = { aot: true };
-
-    host.writeMultipleFiles({
-      'src/foo.ts': `
-        import { from as fromPromise } from 'rxjs';
-        export { fromPromise };
-      `,
-      'src/app/app.component.ts': `
-      import { Component } from '@angular/core';
-      import { fromPromise } from '../foo';
-
-       @Component({
-         selector: 'app-root',
-         templateUrl: './app.component.html',
-         styleUrls: ['./app.component.css']
-       })
-       export class AppComponent {
-         title = 'app-component';
-
-         constructor() {
-           console.log(fromPromise(Promise.resolve('test')));
-         }
-       }`,
-    });
-
-    runTargetSpec(host, browserTargetSpec, overrides).pipe(
-      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
-      tap(() => {
-        const fileName = join(outputPath, 'main.js');
-        const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
-        // if the aliased import was dropped this won't be rewired to a webpack module.
-        expect(content).toMatch(/rxjs__WEBPACK_IMPORTED_.+[\"from\"]/);
-        expect(content).toMatch(/rxjs__WEBPACK_IMPORTED_.+[\"fromPromise\"]/);
-      }),
-    ).toPromise().then(done, done.fail);
-  });
-
-  it('works with aliased imports from an alias export', (done) => {
-    const overrides = { aot: true };
-
-    host.writeMultipleFiles({
-      'src/foo.ts': `
-        export { from as fromPromise } from 'rxjs';
-      `,
-      'src/app/app.component.ts': `
-      import { Component } from '@angular/core';
-      import { fromPromise } from '../foo';
-
-       @Component({
-         selector: 'app-root',
-         templateUrl: './app.component.html',
-         styleUrls: ['./app.component.css']
-       })
-       export class AppComponent {
-         title = 'app-component';
-
-         constructor() {
-           console.log(fromPromise(Promise.resolve('test')));
-         }
-       }`,
-    });
-
-    runTargetSpec(host, browserTargetSpec, overrides).pipe(
-      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
-      tap(() => {
-        const fileName = join(outputPath, 'main.js');
-        const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
-        // if the aliased import was dropped this won't be rewired to a webpack module.
-        expect(content).toMatch(/rxjs__WEBPACK_IMPORTED_.+[\"from\"]/);
-        expect(content).toMatch(/rxjs__WEBPACK_IMPORTED_.+[\"fromPromise\"]/);
-      }),
-    ).toPromise().then(done, done.fail);
-  });
-
 });

packages/ngtools/webpack/src/transformers/ast_helpers.ts

@@ -45,12 +45,13 @@ export function getLastNode(sourceFile: ts.SourceFile): ts.Node | null {
 const basePath = '/project/src/';
 const fileName = basePath + 'test-file.ts';
 
-export function createTypescriptContext(content: string) {
+export function createTypescriptContext(content: string, additionalFiles?: Record<string, string>) {
   // Set compiler options.
   const compilerOptions: ts.CompilerOptions = {
     noEmitOnError: false,
     allowJs: true,
     newLine: ts.NewLineKind.LineFeed,
+    moduleResolution: ts.ModuleResolutionKind.NodeJs,
     target: ts.ScriptTarget.ESNext,
     skipLibCheck: true,
     sourceMap: false,
@@ -68,6 +69,12 @@ export function createTypescriptContext(content: string) {
   // Add a dummy file to host content.
   compilerHost.writeFile(fileName, content, false);
 
+  if (additionalFiles) {
+    for (const key in additionalFiles) {
+      compilerHost.writeFile(basePath + key, additionalFiles[key], false);
+    }
+  }
+
   // Create the TypeScript program.
   const program = ts.createProgram([fileName], compilerOptions, compilerHost);