feat(language-service): add command for getting components for a template file (#40655)

This commit adds a feature to the Angular Language Service that enables
getting the locations for components that use a template file.

Part of https://github.com/angular/vscode-ng-language-service/issues/1081

PR Close #40655

packages/language-service/api.ts

@@ -33,10 +33,13 @@ export type GetTcbResponse = {
   selections: ts.TextSpan[],
 }|undefined;
 
+export type GetComponentLocationsForTemplateResponse = ts.DocumentSpan[];
+
 /**
  * `NgLanguageService` describes an instance of an Angular language service,
  * whose API surface is a strict superset of TypeScript's language service.
  */
 export interface NgLanguageService extends ts.LanguageService {
   getTcb(fileName: string, position: number): GetTcbResponse;
+  getComponentLocationsForTemplate(fileName: string): GetComponentLocationsForTemplateResponse;
 }

packages/language-service/ivy/language_service.ts

@@ -11,11 +11,13 @@ import {CompilerOptions, ConfigurationHost, readConfiguration} from '@angular/co
 import {NgCompiler} from '@angular/compiler-cli/src/ngtsc/core';
 import {ErrorCode, ngErrorCode} from '@angular/compiler-cli/src/ngtsc/diagnostics';
 import {absoluteFrom, absoluteFromSourceFile, AbsoluteFsPath} from '@angular/compiler-cli/src/ngtsc/file_system';
+import {isNamedClassDeclaration} from '@angular/compiler-cli/src/ngtsc/reflection';
 import {TypeCheckShimGenerator} from '@angular/compiler-cli/src/ngtsc/typecheck';
 import {OptimizeFor, TypeCheckingProgramStrategy} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
 import {findFirstMatchingNode} from '@angular/compiler-cli/src/ngtsc/typecheck/src/comments';
 import * as ts from 'typescript/lib/tsserverlibrary';
-import {GetTcbResponse} from '../api';
+
+import {GetComponentLocationsForTemplateResponse, GetTcbResponse} from '../api';
 
 import {LanguageServiceAdapter, LSParseConfigHost} from './adapters';
 import {CompilerFactory} from './compiler_factory';
@@ -200,6 +202,29 @@ export class LanguageService {
     return result;
   }
 
+  getComponentLocationsForTemplate(fileName: string): GetComponentLocationsForTemplateResponse {
+    return this.withCompiler<GetComponentLocationsForTemplateResponse>((compiler) => {
+      const components = compiler.getComponentsWithTemplateFile(fileName);
+      const componentDeclarationLocations: ts.DocumentSpan[] =
+          Array.from(components.values()).map(c => {
+            let contextSpan: ts.TextSpan|undefined = undefined;
+            let textSpan: ts.TextSpan;
+            if (isNamedClassDeclaration(c)) {
+              textSpan = ts.createTextSpanFromBounds(c.name.getStart(), c.name.getEnd());
+              contextSpan = ts.createTextSpanFromBounds(c.getStart(), c.getEnd());
+            } else {
+              textSpan = ts.createTextSpanFromBounds(c.getStart(), c.getEnd());
+            }
+            return {
+              fileName: c.getSourceFile().fileName,
+              textSpan,
+              contextSpan,
+            };
+          });
+      return componentDeclarationLocations;
+    });
+  }
+
   getTcb(fileName: string, position: number): GetTcbResponse {
     return this.withCompiler<GetTcbResponse>(compiler => {
       const templateInfo = getTemplateInfoAtPosition(fileName, position, compiler);

packages/language-service/ivy/ts_plugin.ts

@@ -7,7 +7,9 @@
  */
 
 import * as ts from 'typescript/lib/tsserverlibrary';
-import {GetTcbResponse, NgLanguageService} from '../api';
+
+import {GetComponentLocationsForTemplateResponse, GetTcbResponse, NgLanguageService} from '../api';
+
 import {LanguageService} from './language_service';
 
 export function create(info: ts.server.PluginCreateInfo): NgLanguageService {
@@ -132,6 +134,14 @@ export function create(info: ts.server.PluginCreateInfo): NgLanguageService {
     return ngLS.getTcb(fileName, position);
   }
 
+  /**
+   * Given an external template, finds the associated components that use it as a `templateUrl`.
+   */
+  function getComponentLocationsForTemplate(fileName: string):
+      GetComponentLocationsForTemplateResponse {
+    return ngLS.getComponentLocationsForTemplate(fileName);
+  }
+
   return {
     ...tsLS,
     getSemanticDiagnostics,
@@ -146,6 +156,7 @@ export function create(info: ts.server.PluginCreateInfo): NgLanguageService {
     getCompletionEntrySymbol,
     getTcb,
     getCompilerOptionsDiagnostics,
+    getComponentLocationsForTemplate,
   };
 }
 

packages/language-service/src/ts_plugin.ts

@@ -141,6 +141,11 @@ export function create(info: tss.server.PluginCreateInfo): NgLanguageService {
     return undefined;
   }
 
+  function getComponentLocationsForTemplate(fileName: string) {
+    // Not implemented in VE Language Service
+    return [];
+  }
+
   return {
     // First clone the original TS language service
     ...tsLS,
@@ -154,5 +159,6 @@ export function create(info: tss.server.PluginCreateInfo): NgLanguageService {
     getReferencesAtPosition,
     findRenameLocations,
     getTcb,
+    getComponentLocationsForTemplate,
   };
 }