feat(language-service): add definitions for styleUrls (#32464)

Adds support for `styleUrls` definitions in the same way `templateUrl`
definitions are provided; clicking on styleUrl will take a user to the
respective file.

Unifies some code in determining a URL definition. We first check if a
url is a `templateUrl`; if it's not, we check that it's a `styleUrl` or
return no definitions.

PR Close #32464

integration/language_service_plugin/goldens/styleUrlsDefinition.json

@@ -0,0 +1,32 @@
+{
+  "seq": 0,
+  "type": "response",
+  "command": "definitionAndBoundSpan",
+  "request_seq": 3,
+  "success": true,
+  "body": {
+    "definitions": [
+      {
+        "file": "${PWD}/project/app/style.css",
+        "start": {
+          "line": 1,
+          "offset": 1
+        },
+        "end": {
+          "line": 1,
+          "offset": 1
+        }
+      }
+    ],
+    "textSpan": {
+      "start": {
+        "line": 6,
+        "offset": 16
+      },
+      "end": {
+        "line": 6,
+        "offset": 27
+      }
+    }
+  }
+}

integration/language_service_plugin/project/app/style.css

@@ -0,0 +1,4 @@
+body,
+html {
+  width: 100%;
+}

integration/language_service_plugin/project/app/widget.component.ts

@@ -3,5 +3,6 @@ import { Component } from '@angular/core';
 @Component({
   selector: 'my-widget',
   templateUrl: './widget.component.html',
+  styleUrls: ['./style.css'],
 })
 export class WidgetComponent  { name = 'Angular'; }

integration/language_service_plugin/test.ts

@@ -177,4 +177,27 @@ describe('Angular Language Service', () => {
     });
     expect(resp2).toMatchGolden('templateUrlDefinition.json');
   });
+
+  it('should perform definitionAndBoundSpan for style URLs', async () => {
+    client.sendRequest('open', {
+      file: `${PWD}/project/app/widget.component.ts`,
+    });
+    client.sendRequest('open', {
+      file: `${PWD}/project/app/style.css`,
+    });
+
+    const resp1 = await client.sendRequest('reload', {
+      file: `${PWD}/project/app/widget.component.ts`,
+      tmpFile: `${PWD}/project/app/widget.component.ts`,
+    }) as any;
+    expect(resp1.command).toBe('reload');
+    expect(resp1.success).toBe(true);
+
+    const resp2 = await client.sendRequest('definitionAndBoundSpan', {
+      file: `${PWD}/project/app/widget.component.ts`,
+      line: 6,
+      offset: 18,
+    });
+    expect(resp2).toMatchGolden('styleUrlsDefinition.json');
+  });
 });

packages/language-service/src/definitions.ts

@@ -84,20 +84,39 @@ export function getTsDefinitionAndBoundSpan(
 /**
  * Attempts to get the definition of a file whose URL is specified in a property assignment in a
  * directive decorator.
- * Currently applies to `templateUrl` properties.
+ * Currently applies to `templateUrl` and `styleUrls` properties.
  */
 function getUrlFromProperty(
     urlNode: ts.StringLiteralLike,
     tsLsHost: Readonly<ts.LanguageServiceHost>): ts.DefinitionInfoAndBoundSpan|undefined {
-  const asgn = getPropertyAssignmentFromValue(urlNode);
+  // Get the property assignment node corresponding to the `templateUrl` or `styleUrls` assignment.
-  if (!asgn) return;
+  // These assignments are specified differently; `templateUrl` is a string, and `styleUrls` is
-  // If the URL is not a property of a class decorator, don't generate definitions for it.
+  // an array of strings:
+  //   {
+  //        templateUrl: './template.ng.html',
+  //        styleUrls: ['./style.css', './other-style.css']
+  //   }
+  // `templateUrl`'s property assignment can be found from the string literal node;
+  // `styleUrls`'s property assignment can be found from the array (parent) node.
+  //
+  // First search for `templateUrl`.
+  let asgn = getPropertyAssignmentFromValue(urlNode);
+  if (!asgn || asgn.name.getText() !== 'templateUrl') {
+    // `templateUrl` assignment not found; search for `styleUrls` array assignment.
+    asgn = getPropertyAssignmentFromValue(urlNode.parent);
+    if (!asgn || asgn.name.getText() !== 'styleUrls') {
+      // Nothing found, bail.
+      return;
+    }
+  }
+
+  // If the property assignment is not a property of a class decorator, don't generate definitions
+  // for it.
   if (!isClassDecoratorProperty(asgn)) return;
 
   const sf = urlNode.getSourceFile();
-  switch (asgn.name.getText()) {
+  // Extract url path specified by the url node, which is relative to the TypeScript source file
-    case 'templateUrl':
+  // the url node is defined in.
-      // Extract definition of the template file specified by this `templateUrl` property.
   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
@@ -122,7 +141,4 @@ function getUrlFromProperty(
       length: urlNode.getWidth() - 2,
     },
   };
-    default:
-      return undefined;
-  }
 }

packages/language-service/test/definitions_spec.ts

@@ -275,4 +275,27 @@ describe('definitions', () => {
     expect(def.fileName).toBe('/app/test.ng');
     expect(def.textSpan).toEqual({start: 0, length: 0});
   });
+
+  it('should be able to find a stylesheet from a url', () => {
+    const fileName = mockHost.addCode(`
+	      @Component({
+	        templateUrl: './test.ng',
+                styleUrls: ['./«test».css'],
+	      })
+	      export class MyComponent {}`);
+
+    const marker = mockHost.getReferenceMarkerFor(fileName, 'test');
+    const result = ngService.getDefinitionAt(fileName, marker.start);
+
+    expect(result).toBeDefined();
+    const {textSpan, definitions} = result !;
+
+    expect(textSpan).toEqual({start: marker.start - 2, length: 10});
+
+    expect(definitions).toBeDefined();
+    expect(definitions !.length).toBe(1);
+    const [def] = definitions !;
+    expect(def.fileName).toBe('/app/test.css');
+    expect(def.textSpan).toEqual({start: 0, length: 0});
+  });
 });

packages/language-service/test/test_data.ts

@@ -232,6 +232,11 @@ export class ShowIf {
       <label>name: </label>
     </div>
     &~{entity-amp}amp;
-    `
+`,
+    'test.css': `
+body, html {
+  width: 100%;
+}
+`,
   }
 };