fix(language-service): reset MockHost after every spec instead of creating new LS

packages/language-service/test/BUILD.bazel

@@ -13,7 +13,6 @@ ts_library(
         "//packages/compiler",
         "//packages/compiler-cli/test:test_utils",
         "//packages/language-service",
-        "@npm//reflect-metadata",
         "@npm//typescript",
     ],
 )

packages/language-service/test/definitions_spec.ts

@@ -9,24 +9,17 @@
 import * as ts from 'typescript';
 
 import {createLanguageService} from '../src/language_service';
-import {LanguageService} from '../src/types';
 import {TypeScriptServiceHost} from '../src/typescript_host';
 
 import {MockTypescriptHost} from './test_utils';
 
 describe('definitions', () => {
-  let mockHost: MockTypescriptHost;
-  let service: ts.LanguageService;
-  let ngHost: TypeScriptServiceHost;
-  let ngService: LanguageService;
-
-  beforeEach(() => {
-    // Create a new mockHost every time to reset any files that are overridden.
-    mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
-    service = ts.createLanguageService(mockHost);
-    ngHost = new TypeScriptServiceHost(mockHost, service);
-    ngService = createLanguageService(ngHost);
-  });
+  const mockHost = new MockTypescriptHost(['/app/main.ts']);
+  const service = ts.createLanguageService(mockHost);
+  const ngHost = new TypeScriptServiceHost(mockHost, service);
+  const ngService = createLanguageService(ngHost);
+
+  beforeEach(() => { mockHost.reset(); });
 
   it('should be able to find field in an interpolation', () => {
     const fileName = mockHost.addCode(`
@@ -201,7 +194,6 @@ describe('definitions', () => {
   });
 
   it('should be able to find an input provider', () => {
-    // '/app/parsing-cases.ts', 'tcName',
     const fileName = mockHost.addCode(`
       @Component({
         template: '<test-comp ~{start-my}[«tcName»]="name"~{end-my}></div>'

packages/language-service/test/diagnostics_spec.ts

@@ -8,7 +8,6 @@
 
 import * as ts from 'typescript';
 import {createLanguageService} from '../src/language_service';
-import * as ng from '../src/types';
 import {TypeScriptServiceHost} from '../src/typescript_host';
 import {MockTypescriptHost} from './test_utils';
 
@@ -29,17 +28,12 @@ const NG_FOR_CASES = '/app/ng-for-cases.ts';
 const NG_IF_CASES = '/app/ng-if-cases.ts';
 
 describe('diagnostics', () => {
-  let mockHost: MockTypescriptHost;
-  let ngHost: TypeScriptServiceHost;
-  let tsLS: ts.LanguageService;
-  let ngLS: ng.LanguageService;
-
-  beforeEach(() => {
-    mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
-    tsLS = ts.createLanguageService(mockHost);
-    ngHost = new TypeScriptServiceHost(mockHost, tsLS);
-    ngLS = createLanguageService(ngHost);
-  });
+  const mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
+  const tsLS = ts.createLanguageService(mockHost);
+  const ngHost = new TypeScriptServiceHost(mockHost, tsLS);
+  const ngLS = createLanguageService(ngHost);
+
+  beforeEach(() => { mockHost.reset(); });
 
   it('should produce no diagnostics for test.ng', () => {
     // there should not be any errors on existing external template

packages/language-service/test/hover_spec.ts

@@ -9,23 +9,17 @@
 import * as ts from 'typescript';
 
 import {createLanguageService} from '../src/language_service';
-import {LanguageService} from '../src/types';
 import {TypeScriptServiceHost} from '../src/typescript_host';
 
 import {MockTypescriptHost} from './test_utils';
 
 describe('hover', () => {
-  let mockHost: MockTypescriptHost;
-  let tsLS: ts.LanguageService;
-  let ngLSHost: TypeScriptServiceHost;
-  let ngLS: LanguageService;
-
-  beforeEach(() => {
-    mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
-    tsLS = ts.createLanguageService(mockHost);
-    ngLSHost = new TypeScriptServiceHost(mockHost, tsLS);
-    ngLS = createLanguageService(ngLSHost);
-  });
+  const mockHost = new MockTypescriptHost(['/app/main.ts']);
+  const tsLS = ts.createLanguageService(mockHost);
+  const ngLSHost = new TypeScriptServiceHost(mockHost, tsLS);
+  const ngLS = createLanguageService(ngLSHost);
+
+  beforeEach(() => { mockHost.reset(); });
 
   it('should be able to find field in an interpolation', () => {
     const fileName = mockHost.addCode(`
@@ -184,18 +178,16 @@ describe('hover', () => {
 
   it('should be able to find the NgModule of a directive', () => {
     const fileName = '/app/parsing-cases.ts';
-    mockHost.override(fileName, `
-      import {Directive} from '@angular/core';
-
-      @Directive({
-        selector: '[string-model]',
-      })
-      export class «StringModel» {}`);
-    const marker = mockHost.getReferenceMarkerFor(fileName, 'StringModel');
-    const quickInfo = ngLS.getHoverAt(fileName, marker.start);
+    const content = mockHost.readFile(fileName) !;
+    const position = content.indexOf('StringModel');
+    expect(position).toBeGreaterThan(0);
+    const quickInfo = ngLS.getHoverAt(fileName, position);
     expect(quickInfo).toBeTruthy();
     const {textSpan, displayParts} = quickInfo !;
-    expect(textSpan).toEqual(marker);
+    expect(textSpan).toEqual({
+      start: position,
+      length: 'StringModel'.length,
+    });
     expect(toText(displayParts)).toBe('(directive) AppModule.StringModel: class');
   });
 });

packages/language-service/test/template_references_spec.ts

@@ -15,18 +15,12 @@ import {TypeScriptServiceHost} from '../src/typescript_host';
 import {MockTypescriptHost} from './test_utils';
 
 describe('references', () => {
-  let documentRegistry = ts.createDocumentRegistry();
-  let mockHost: MockTypescriptHost;
-  let service: ts.LanguageService;
-  let ngHost: TypeScriptServiceHost;
-  let ngService: LanguageService = createLanguageService(undefined !);
-
-  beforeEach(() => {
-    mockHost = new MockTypescriptHost(['/app/main.ts', '/app/parsing-cases.ts']);
-    service = ts.createLanguageService(mockHost, documentRegistry);
-    ngHost = new TypeScriptServiceHost(mockHost, service);
-    ngService = createLanguageService(ngHost);
-  });
+  const mockHost = new MockTypescriptHost(['/app/main.ts']);
+  const service = ts.createLanguageService(mockHost);
+  const ngHost = new TypeScriptServiceHost(mockHost, service);
+  const ngService = createLanguageService(ngHost);
+
+  beforeEach(() => { mockHost.reset(); });
 
   it('should be able to get template references',
      () => { expect(() => ngService.getTemplateReferences()).not.toThrow(); });

packages/language-service/test/test_utils.ts

@@ -92,7 +92,7 @@ const COMPILER_OPTIONS: Readonly<ts.CompilerOptions> = {
 };
 
 export class MockTypescriptHost implements ts.LanguageServiceHost {
-  private angularPath?: string;
+  private readonly angularPath: string;
   private readonly nodeModulesPath: string;
   private readonly scriptVersion = new Map<string, number>();
   private readonly overrides = new Map<string, string>();
@@ -127,14 +127,16 @@ export class MockTypescriptHost implements ts.LanguageServiceHost {
   }
 
   addScript(fileName: string, content: string) {
+    if (this.scriptVersion.has(fileName)) {
+      throw new Error(`${fileName} is already in the root files.`);
+    }
+    this.scriptVersion.set(fileName, 0);
     this.projectVersion++;
     this.overrides.set(fileName, content);
     this.overrideDirectory.add(path.dirname(fileName));
     this.scriptNames.push(fileName);
   }
 
-  forgetAngular() { this.angularPath = undefined; }
-
   overrideOptions(options: Partial<ts.CompilerOptions>) {
     this.options = {...this.options, ...options};
     this.projectVersion++;
@@ -185,6 +187,16 @@ export class MockTypescriptHost implements ts.LanguageServiceHost {
    * Reset the project to its original state, effectively removing all overrides.
    */
   reset() {
+    // project version and script version must be monotonically increasing,
+    // they must not be reset to zero.
+    this.projectVersion++;
+    for (const fileName of this.overrides.keys()) {
+      const version = this.scriptVersion.get(fileName);
+      if (version === undefined) {
+        throw new Error(`No prior version found for ${fileName}`);
+      }
+      this.scriptVersion.set(fileName, version + 1);
+    }
     // Remove overrides from scriptNames
     let length = 0;
     for (let i = 0; i < this.scriptNames.length; ++i) {
@@ -251,7 +263,7 @@ export class MockTypescriptHost implements ts.LanguageServiceHost {
           return result;
         }
       }
-      if (this.angularPath && name.startsWith('/' + node_modules + at_angular)) {
+      if (name.startsWith('/' + node_modules + at_angular)) {
         return this.myPath.posix.join(
             this.angularPath, name.substr(node_modules.length + at_angular.length + 1));
       }

packages/language-service/test/typescript_host_spec.ts

@@ -6,7 +6,6 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import 'reflect-metadata';
 import * as ts from 'typescript';
 
 import {TypeScriptServiceHost} from '../src/typescript_host';