feat(language-service): Implement go to definition for style and template urls (#39202)

This commit enables the Ivy Language Service to 'go to definition' of a
templateUrl or styleUrl, which would jump to the template/style file
itself.

PR Close #39202

packages/language-service/common/BUILD.bazel

@@ -6,7 +6,6 @@ ts_library(
     name = "common",
     srcs = glob(["*.ts"]),
     deps = [
-        "@npm//@types/node",
         "@npm//typescript",
     ],
 )

packages/language-service/common/definitions.ts

@@ -6,24 +6,35 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import * as path from 'path';
 import * as ts from 'typescript';
 
 import {findTightestNode, getClassDeclFromDecoratorProp, getPropertyAssignmentFromValue} from './ts_utils';
 
+export interface ResourceResolver {
+  /**
+   * Resolve the url of a resource relative to the file that contains the reference to it.
+   *
+   * @param file The, possibly relative, url of the resource.
+   * @param basePath The path to the file that contains the URL of the resource.
+   * @returns A resolved url of resource.
+   * @throws An error if the resource cannot be resolved.
+   */
+  resolve(file: string, basePath: string): string;
+}
+
 /**
  * Gets an Angular-specific definition in a TypeScript source file.
  */
 export function getTsDefinitionAndBoundSpan(
     sf: ts.SourceFile, position: number,
-    tsLsHost: Pick<ts.LanguageServiceHost, 'fileExists'>): ts.DefinitionInfoAndBoundSpan|undefined {
+    resourceResolver: ResourceResolver): ts.DefinitionInfoAndBoundSpan|undefined {
   const node = findTightestNode(sf, position);
   if (!node) return;
   switch (node.kind) {
     case ts.SyntaxKind.StringLiteral:
     case ts.SyntaxKind.NoSubstitutionTemplateLiteral:
       // Attempt to extract definition of a URL in a property assignment.
-      return getUrlFromProperty(node as ts.StringLiteralLike, tsLsHost);
+      return getUrlFromProperty(node as ts.StringLiteralLike, resourceResolver);
     default:
       return undefined;
   }
@@ -34,9 +45,8 @@ export function getTsDefinitionAndBoundSpan(
  * directive decorator.
  * Currently applies to `templateUrl` and `styleUrls` properties.
  */
-function getUrlFromProperty(
-    urlNode: ts.StringLiteralLike,
-    tsLsHost: Pick<ts.LanguageServiceHost, 'fileExists'>): ts.DefinitionInfoAndBoundSpan|undefined {
+function getUrlFromProperty(urlNode: ts.StringLiteralLike, resourceResolver: ResourceResolver):
+    ts.DefinitionInfoAndBoundSpan|undefined {
   // Get the property assignment node corresponding to the `templateUrl` or `styleUrls` assignment.
   // These assignments are specified differently; `templateUrl` is a string, and `styleUrls` is
   // an array of strings:
@@ -65,13 +75,13 @@ function getUrlFromProperty(
   }
 
   const sf = urlNode.getSourceFile();
-  // Extract url path specified by the url node, which is relative to the TypeScript source file
-  // the url node is defined in.
-  const url = path.join(path.dirname(sf.fileName), urlNode.text);
-
-  // If the file does not exist, bail. It is possible that the TypeScript language service host
-  // does not have a `fileExists` method, in which case optimistically assume the file exists.
-  if (tsLsHost.fileExists && !tsLsHost.fileExists(url)) return;
+  let url: string;
+  try {
+    url = resourceResolver.resolve(urlNode.text, sf.fileName);
+  } catch {
+    // If the file does not exist, bail.
+    return;
+  }
 
   const templateDefinitions: ts.DefinitionInfo[] = [{
     kind: ts.ScriptElementKind.externalModuleName,
@@ -79,6 +89,9 @@ function getUrlFromProperty(
     containerKind: ts.ScriptElementKind.unknown,
     containerName: '',
     // Reading the template is expensive, so don't provide a preview.
+    // TODO(ayazhafiz): Consider providing an actual span:
+    //  1. We're likely to read the template anyway
+    //  2. We could show just the first 100 chars or so
     textSpan: {start: 0, length: 0},
     fileName: url,
   }];

packages/language-service/common/ts_utils.ts

@@ -83,5 +83,5 @@ export function getClassDeclOfInlineTemplateNode(templateStringNode: ts.Node): t
   if (!tmplAsgn) {
     return;
   }
-  return getClassDeclFromDecoratorProp(tmplAsgn)
+  return getClassDeclFromDecoratorProp(tmplAsgn);
 }

packages/language-service/ivy/BUILD.bazel

@@ -13,6 +13,7 @@ ts_library(
         "//packages/compiler-cli/src/ngtsc/file_system",
         "//packages/compiler-cli/src/ngtsc/incremental",
         "//packages/compiler-cli/src/ngtsc/reflection",
+        "//packages/compiler-cli/src/ngtsc/resource",
         "//packages/compiler-cli/src/ngtsc/shims",
         "//packages/compiler-cli/src/ngtsc/typecheck",
         "//packages/compiler-cli/src/ngtsc/typecheck/api",

packages/language-service/ivy/compiler_factory.ts

@@ -12,7 +12,8 @@ import {TrackedIncrementalBuildStrategy} from '@angular/compiler-cli/src/ngtsc/i
 import {TypeCheckingProgramStrategy} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
 import * as ts from 'typescript/lib/tsserverlibrary';
 
-import {isExternalTemplate, LanguageServiceAdapter} from './language_service_adapter';
+import {LanguageServiceAdapter} from './language_service_adapter';
+import {isExternalTemplate} from './utils';
 
 export class CompilerFactory {
   private readonly incrementalStrategy = new TrackedIncrementalBuildStrategy();

packages/language-service/ivy/definitions.ts

@@ -11,8 +11,10 @@ import {NgCompiler} from '@angular/compiler-cli/src/ngtsc/core';
 import {DirectiveSymbol, DomBindingSymbol, ElementSymbol, ShimLocation, Symbol, SymbolKind, TemplateSymbol} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
 import * as ts from 'typescript';
 
+import {getTsDefinitionAndBoundSpan, ResourceResolver} from '../common/definitions';
+
 import {getPathToNodeAtPosition} from './hybrid_visitor';
-import {flatMap, getDirectiveMatchesForAttribute, getDirectiveMatchesForElementTag, getTemplateInfoAtPosition, getTextSpanOfNode, isDollarEvent, TemplateInfo, toTextSpan} from './utils';
+import {flatMap, getDirectiveMatchesForAttribute, getDirectiveMatchesForElementTag, getTemplateInfoAtPosition, getTextSpanOfNode, isDollarEvent, isTypeScriptFile, TemplateInfo, toTextSpan} from './utils';
 
 interface DefinitionMeta {
   node: AST|TmplAstNode;
@@ -25,13 +27,25 @@ interface HasShimLocation {
 }
 
 export class DefinitionBuilder {
-  constructor(private readonly tsLS: ts.LanguageService, private readonly compiler: NgCompiler) {}
+  constructor(
+      private readonly tsLS: ts.LanguageService, private readonly compiler: NgCompiler,
+      private readonly resourceResolver: ResourceResolver) {}
 
   getDefinitionAndBoundSpan(fileName: string, position: number): ts.DefinitionInfoAndBoundSpan
       |undefined {
     const templateInfo = getTemplateInfoAtPosition(fileName, position, this.compiler);
     if (templateInfo === undefined) {
-      return;
+      // We were unable to get a template at the given position. If we are in a TS file, instead
+      // attempt to get an Angular definition at the location inside a TS file (examples of this
+      // would be templateUrl or a url in styleUrls).
+      if (!isTypeScriptFile(fileName)) {
+        return;
+      }
+      const sf = this.compiler.getNextProgram().getSourceFile(fileName);
+      if (!sf) {
+        return;
+      }
+      return getTsDefinitionAndBoundSpan(sf, position, this.resourceResolver);
     }
     const definitionMeta = this.getDefinitionMetaAtPosition(templateInfo, position);
     // The `$event` of event handlers would point to the $event parameter in the shim file, as in

packages/language-service/ivy/language_service.ts

@@ -7,7 +7,6 @@
  */
 
 import {CompilerOptions, createNgCompilerOptions} from '@angular/compiler-cli';
-import {NgCompiler} from '@angular/compiler-cli/src/ngtsc/core';
 import {absoluteFromSourceFile, AbsoluteFsPath} from '@angular/compiler-cli/src/ngtsc/file_system';
 import {TypeCheckShimGenerator} from '@angular/compiler-cli/src/ngtsc/typecheck';
 import {OptimizeFor, TypeCheckingProgramStrategy} from '@angular/compiler-cli/src/ngtsc/typecheck/api';
@@ -15,8 +14,9 @@ import * as ts from 'typescript/lib/tsserverlibrary';
 
 import {CompilerFactory} from './compiler_factory';
 import {DefinitionBuilder} from './definitions';
-import {isExternalTemplate, isTypeScriptFile, LanguageServiceAdapter} from './language_service_adapter';
+import {LanguageServiceAdapter} from './language_service_adapter';
 import {QuickInfoBuilder} from './quick_info';
+import {isTypeScriptFile} from './utils';
 
 export class LanguageService {
   private options: CompilerOptions;
@@ -57,8 +57,8 @@ export class LanguageService {
   getDefinitionAndBoundSpan(fileName: string, position: number): ts.DefinitionInfoAndBoundSpan
       |undefined {
     const compiler = this.compilerFactory.getOrCreateWithChangedFile(fileName, this.options);
-    const results =
-        new DefinitionBuilder(this.tsLS, compiler).getDefinitionAndBoundSpan(fileName, position);
+    const results = new DefinitionBuilder(this.tsLS, compiler, this.adapter)
+                        .getDefinitionAndBoundSpan(fileName, position);
     this.compilerFactory.registerLastKnownProgram();
     return results;
   }
@@ -66,8 +66,8 @@ export class LanguageService {
   getTypeDefinitionAtPosition(fileName: string, position: number):
       readonly ts.DefinitionInfo[]|undefined {
     const compiler = this.compilerFactory.getOrCreateWithChangedFile(fileName, this.options);
-    const results =
-        new DefinitionBuilder(this.tsLS, compiler).getTypeDefinitionsAtPosition(fileName, position);
+    const results = new DefinitionBuilder(this.tsLS, compiler, this.adapter)
+                        .getTypeDefinitionsAtPosition(fileName, position);
     this.compilerFactory.registerLastKnownProgram();
     return results;
   }

packages/language-service/ivy/language_service_adapter.ts

@@ -8,10 +8,15 @@
 
 import {NgCompilerAdapter} from '@angular/compiler-cli/src/ngtsc/core/api';
 import {absoluteFrom, AbsoluteFsPath} from '@angular/compiler-cli/src/ngtsc/file_system';
+import {AdapterResourceLoader} from '@angular/compiler-cli/src/ngtsc/resource';
 import {isShim} from '@angular/compiler-cli/src/ngtsc/shims';
 import * as ts from 'typescript/lib/tsserverlibrary';
 
-export class LanguageServiceAdapter implements NgCompilerAdapter {
+import {ResourceResolver} from '../common/definitions';
+
+import {isTypeScriptFile} from './utils';
+
+export class LanguageServiceAdapter implements NgCompilerAdapter, ResourceResolver {
   readonly entryPoint = null;
   readonly constructionDiagnostics: ts.Diagnostic[] = [];
   readonly ignoreForEmit: Set<ts.SourceFile> = new Set();
@@ -75,12 +80,9 @@ export class LanguageServiceAdapter implements NgCompilerAdapter {
     const latestVersion = this.project.getScriptVersion(fileName);
     return lastVersion !== latestVersion;
   }
-}
 
-export function isTypeScriptFile(fileName: string): boolean {
-  return fileName.endsWith('.ts');
-}
-
-export function isExternalTemplate(fileName: string): boolean {
-  return !isTypeScriptFile(fileName);
+  resolve(file: string, basePath: string): string {
+    const loader = new AdapterResourceLoader(this, this.project.getCompilationSettings());
+    return loader.resolve(file, basePath);
+  }
 }

packages/language-service/ivy/test/definitions_spec.ts

@@ -448,6 +448,53 @@ describe('definitions', () => {
     });
   });
 
+  describe('external resources', () => {
+    it('should be able to find a template from a url', () => {
+      const {position, text} = service.overwrite(APP_COMPONENT, `
+        import {Component} from '@angular/core';
+	      @Component({
+	        templateUrl: './tes¦t.ng',
+	      })
+	      export class MyComponent {}`);
+      const result = ngLS.getDefinitionAndBoundSpan(APP_COMPONENT, position);
+
+      expect(result).toBeDefined();
+      const {textSpan, definitions} = result!;
+
+      expect(text.substring(textSpan.start, textSpan.start + textSpan.length)).toEqual('./test.ng');
+
+      expect(definitions).toBeDefined();
+      expect(definitions!.length).toBe(1);
+      const [def] = definitions!;
+      expect(def.fileName).toContain('/app/test.ng');
+      expect(def.textSpan).toEqual({start: 0, length: 0});
+    });
+
+    it('should be able to find a stylesheet from a url', () => {
+      const {position, text} = service.overwrite(APP_COMPONENT, `
+        import {Component} from '@angular/core';
+	      @Component({
+	        template: 'empty',
+	        styleUrls: ['./te¦st.css']
+	      })
+	      export class MyComponent {}`);
+      const result = ngLS.getDefinitionAndBoundSpan(APP_COMPONENT, position);
+
+
+      expect(result).toBeDefined();
+      const {textSpan, definitions} = result!;
+
+      expect(text.substring(textSpan.start, textSpan.start + textSpan.length))
+          .toEqual('./test.css');
+
+      expect(definitions).toBeDefined();
+      expect(definitions!.length).toBe(1);
+      const [def] = definitions!;
+      expect(def.fileName).toContain('/app/test.css');
+      expect(def.textSpan).toEqual({start: 0, length: 0});
+    });
+  });
+
   function getDefinitionsAndAssertBoundSpan(
       {templateOverride, expectedSpanText}: {templateOverride: string, expectedSpanText: string}):
       Array<{textSpan: string, contextSpan: string | undefined, fileName: string}> {

packages/language-service/ivy/test/mock_host.ts

@@ -8,7 +8,8 @@
 
 import {join} from 'path';
 import * as ts from 'typescript/lib/tsserverlibrary';
-import {isTypeScriptFile} from '../language_service_adapter';
+
+import {isTypeScriptFile} from '../utils';
 
 const logger: ts.server.Logger = {
   close(): void{},

packages/language-service/ivy/utils.ts

@@ -14,6 +14,7 @@ import * as t from '@angular/compiler/src/render3/r3_ast';         // t for temp
 import * as ts from 'typescript';
 
 import {ALIAS_NAME, SYMBOL_PUNC} from '../common/quick_info';
+import {findTightestNode, getClassDeclOfInlineTemplateNode} from '../common/ts_utils';
 
 export function getTextSpanOfNode(node: t.Node|e.AST): ts.TextSpan {
   if (isTemplateNodeWithKeyAndValue(node)) {
@@ -70,8 +71,8 @@ export interface TemplateInfo {
  */
 export function getTemplateInfoAtPosition(
     fileName: string, position: number, compiler: NgCompiler): TemplateInfo|undefined {
-  if (fileName.endsWith('.ts')) {
-    return getInlineTemplateInfoAtPosition(fileName, position, compiler);
+  if (isTypeScriptFile(fileName)) {
+    return getTemplateInfoFromClassMeta(fileName, position, compiler);
   } else {
     return getFirstComponentForTemplateFile(fileName, compiler);
   }
@@ -116,28 +117,29 @@ function getFirstComponentForTemplateFile(fileName: string, compiler: NgCompiler
 /**
  * Retrieves the `ts.ClassDeclaration` at a location along with its template nodes.
  */
-function getInlineTemplateInfoAtPosition(
+function getTemplateInfoFromClassMeta(
     fileName: string, position: number, compiler: NgCompiler): TemplateInfo|undefined {
+  const classDecl = getClassDeclForInlineTemplateAtPosition(fileName, position, compiler);
+  if (!classDecl || !classDecl.name) {  // Does not handle anonymous class
+    return;
+  }
+  const template = compiler.getTemplateTypeChecker().getTemplate(classDecl);
+  if (template === null) {
+    return;
+  }
+
+  return {template, component: classDecl};
+}
+
+function getClassDeclForInlineTemplateAtPosition(
+    fileName: string, position: number, compiler: NgCompiler): ts.ClassDeclaration|undefined {
   const sourceFile = compiler.getNextProgram().getSourceFile(fileName);
   if (!sourceFile) {
     return undefined;
   }
-
-  // We only support top level statements / class declarations
-  for (const statement of sourceFile.statements) {
-    if (!ts.isClassDeclaration(statement) || position < statement.pos || position > statement.end) {
-      continue;
-    }
-
-    const template = compiler.getTemplateTypeChecker().getTemplate(statement);
-    if (template === null) {
-      return undefined;
-    }
-
-    return {template, component: statement};
-  }
-
-  return undefined;
+  const node = findTightestNode(sourceFile, position);
+  if (!node) return;
+  return getClassDeclOfInlineTemplateNode(node);
 }
 
 /**
@@ -291,3 +293,11 @@ export function flatMap<T, R>(items: T[]|readonly T[], f: (item: T) => R[] | rea
   }
   return results;
 }
+
+export function isTypeScriptFile(fileName: string): boolean {
+  return fileName.endsWith('.ts');
+}
+
+export function isExternalTemplate(fileName: string): boolean {
+  return !isTypeScriptFile(fileName);
+}

packages/language-service/src/language_service.ts

@@ -6,9 +6,11 @@
  * found in the LICENSE file at https://angular.io/license
  */
 
-import {getTsDefinitionAndBoundSpan} from '@angular/language-service/common/definitions';
+import * as path from 'path';
 import * as tss from 'typescript/lib/tsserverlibrary';
 
+import {getTsDefinitionAndBoundSpan, ResourceResolver} from '../common/definitions';
+
 import {getTemplateCompletions} from './completions';
 import {getDefinitionAndBoundSpan} from './definitions';
 import {getDeclarationDiagnostics, getTemplateDiagnostics, ngDiagnosticToTsDiagnostic} from './diagnostics';
@@ -76,13 +78,13 @@ class LanguageServiceImpl implements ng.LanguageService {
     if (templateInfo) {
       return getDefinitionAndBoundSpan(templateInfo, position);
     }
-
     // Attempt to get Angular-specific definitions in a TypeScript file, like templates defined
     // in a `templateUrl` property.
     if (fileName.endsWith('.ts')) {
       const sf = this.host.getSourceFile(fileName);
       if (sf) {
-        return getTsDefinitionAndBoundSpan(sf, position, this.host.tsLsHost);
+        return getTsDefinitionAndBoundSpan(
+            sf, position, new ViewEngineLSResourceResolver(this.host.tsLsHost));
       }
     }
   }
@@ -113,3 +115,20 @@ class LanguageServiceImpl implements ng.LanguageService {
     return this.host.tsLS.getReferencesAtPosition(tsDef.fileName, tsDef.textSpan.start);
   }
 }
+
+class ViewEngineLSResourceResolver implements ResourceResolver {
+  constructor(private host: ts.LanguageServiceHost) {}
+
+  resolve(file: string, basePath: string): string {
+    // Extract url path specified by the url node, which is relative to the TypeScript source file
+    // the url node is defined in.
+    const url = path.join(path.dirname(basePath), file);
+
+    // If the file does not exist, bail. It is possible that the TypeScript language service host
+    // does not have a `fileExists` method, in which case optimistically assume the file exists.
+    if (this.host.fileExists && !this.host.fileExists(url)) {
+      throw new Error(`ResourceResolver: could not resolve ${url} in context of ${basePath})`);
+    }
+    return url;
+  }
+}

packages/language-service/test/BUILD.bazel

@@ -59,6 +59,7 @@ ts_library(
         "//packages/compiler",
         "//packages/language-service",
         "//packages/language-service:ts_utils",
+        "//packages/language-service/common",
         "@npm//typescript",
     ],
 )

packages/language-service/test/utils_spec.ts

@@ -9,7 +9,8 @@
 import * as ng from '@angular/compiler';
 import * as ts from 'typescript';
 
-import {getClassDeclFromDecoratorProp, getDirectiveClassLike} from '../src/ts_utils';
+import {getClassDeclFromDecoratorProp} from '../common/ts_utils';
+import {getDirectiveClassLike} from '../src/ts_utils';
 import {getPathToNodeAtPosition} from '../src/utils';
 import {MockTypescriptHost} from './test_utils';