test(language-service): Make tests better by adding more assertions (#32630)

This commit adds more assertions to a few smoke tests in typescript_host_spec.ts

PR Close #32630

packages/language-service/test/test_utils.ts

@@ -6,6 +6,7 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
+import {CompileNgModuleMetadata, NgAnalyzedModules} from '@angular/compiler';
 import {setup} from '@angular/compiler-cli/test/test_support';
 import * as fs from 'fs';
 import * as path from 'path';
@@ -403,3 +404,18 @@ function getReferenceMarkers(value: string): ReferenceResult {
 function removeReferenceMarkers(value: string): string {
   return value.replace(referenceMarker, (match, text) => text.replace(/ᐱ/g, ''));
 }
+
+/**
+ * Find the StaticSymbol that has the specified `directiveName` and return its
+ * Angular metadata, if any.
+ * @param ngModules analyzed modules
+ * @param directiveName
+ */
+export function findDirectiveMetadataByName(
+    ngModules: NgAnalyzedModules, directiveName: string): CompileNgModuleMetadata|undefined {
+  for (const [key, value] of ngModules.ngModuleByPipeOrDirective) {
+    if (key.name === directiveName) {
+      return value;
+    }
+  }
+}

packages/language-service/test/typescript_host_spec.ts

@@ -12,35 +12,47 @@ import * as ts from 'typescript';
 import {TypeScriptServiceHost} from '../src/typescript_host';
 
 import {toh} from './test_data';
-import {MockTypescriptHost} from './test_utils';
+import {MockTypescriptHost, findDirectiveMetadataByName} from './test_utils';
 
 
 describe('TypeScriptServiceHost', () => {
-  it('should be able to create a typescript host', () => {
-    const tsLSHost = new MockTypescriptHost(['/app/main.ts'], toh);
-    const tsLS = ts.createLanguageService(tsLSHost);
-    expect(() => new TypeScriptServiceHost(tsLSHost, tsLS)).not.toThrow();
-  });
-
-  it('should be able to analyze modules', () => {
+  it('should be able to create a typescript host and analyze modules', () => {
     const tsLSHost = new MockTypescriptHost(['/app/main.ts'], toh);
     const tsLS = ts.createLanguageService(tsLSHost);
     const ngLSHost = new TypeScriptServiceHost(tsLSHost, tsLS);
-    expect(ngLSHost.getAnalyzedModules()).toBeDefined();
+    const analyzedModules = ngLSHost.getAnalyzedModules();
+    expect(analyzedModules.files.length).toBeGreaterThan(0);
+    expect(analyzedModules.ngModules.length).toBeGreaterThan(0);
+    expect(analyzedModules.ngModuleByPipeOrDirective.size).toBeGreaterThan(0);
+    expect(analyzedModules.symbolsMissingModule).toEqual([]);
+    // NgClass is defined in @angular/common, which is imported in main.ts
+    const ngClass = findDirectiveMetadataByName(analyzedModules, 'NgClass');
+    expect(ngClass).toBeDefined();
+    // AppComponent is defined in app.component.ts
+    const appComp = findDirectiveMetadataByName(analyzedModules, 'AppComponent');
+    expect(appComp).toBeDefined();
   });
 
   it('should be able to analyze modules without a tsconfig.json file', () => {
     const tsLSHost = new MockTypescriptHost(['foo.ts'], toh);
     const tsLS = ts.createLanguageService(tsLSHost);
     const ngLSHost = new TypeScriptServiceHost(tsLSHost, tsLS);
-    expect(ngLSHost.getAnalyzedModules()).toBeDefined();
+    const analyzedModules = ngLSHost.getAnalyzedModules();
+    expect(analyzedModules.files.length).toBeGreaterThan(0);
+    expect(analyzedModules.ngModules.length).toBe(0);
+    expect(analyzedModules.ngModuleByPipeOrDirective.size).toBe(0);
+    expect(analyzedModules.symbolsMissingModule).toEqual([]);
   });
 
   it('should not throw if there is no script names', () => {
     const tsLSHost = new MockTypescriptHost([], toh);
     const tsLS = ts.createLanguageService(tsLSHost);
     const ngLSHost = new TypeScriptServiceHost(tsLSHost, tsLS);
-    expect(() => ngLSHost.getAnalyzedModules()).not.toThrow();
+    const analyzedModules = ngLSHost.getAnalyzedModules();
+    expect(analyzedModules.files.length).toBe(0);
+    expect(analyzedModules.ngModules.length).toBe(0);
+    expect(analyzedModules.ngModuleByPipeOrDirective.size).toBe(0);
+    expect(analyzedModules.symbolsMissingModule).toBeUndefined();
   });
 
   it('should clear the caches if program changes', () => {

packages/tsconfig.json

@@ -4,6 +4,7 @@
     // packages like the native "http" module are resolved to the Angular "http" package.
     "baseUrl": "..",
     "declaration": true,
+    "downlevelIteration": true,
     "experimentalDecorators": true,
     "emitDecoratorMetadata": true,
     "module": "commonjs",