fix(@ngtools/webpack): delete all virtual files for styles on change

Fixes #15143

Author: alan-agius4

packages/angular_devkit/build_angular/test/browser/rebuild_spec_large.ts

@@ -8,14 +8,16 @@
 // tslint:disable:no-big-function
 import { Architect } from '@angular-devkit/architect';
 import { TestLogger } from '@angular-devkit/architect/testing';
-import { logging, normalize, virtualFs } from '@angular-devkit/core';
+import { join, logging, normalize, virtualFs } from '@angular-devkit/core';
 import { debounceTime, take, takeWhile, tap } from 'rxjs/operators';
 import {
   createArchitect,
   host,
   ivyEnabled,
   lazyModuleFiles,
-  lazyModuleStringImport,
+  lazyModuleFnImport,
+  lazyModuleStringImport,  
+  outputPath,
 } from '../utils';
 
 describe('Browser Builder rebuilds', () => {
@@ -477,4 +479,64 @@ describe('Browser Builder rebuilds', () => {
       .toPromise();
     await run.stop();
   });
+
+  it('rebuilds AOT on CSS changes', async () => {
+    const overrides = { watch: true, aot: true };
+
+    let buildCount = 1;
+    const run = await architect.scheduleTarget(target, overrides);
+    await run.output.pipe(
+      debounceTime(1000),
+      tap(() => {
+        const content = virtualFs.fileBufferToString(
+          host.scopedSync().read(join(outputPath, 'main.js')),
+        );
+
+        switch (buildCount) {
+          case 1:
+              expect(content).not.toContain('color: green');
+              host.appendToFile('src/app/app.component.css', 'h1 { color: green; }');
+            break;
+          case 2:
+              expect(content).toContain('color: green');
+            break;
+        }
+
+        buildCount++;
+      }),
+      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
+      take(2),
+    ).toPromise();
+    await run.stop();
+  });
+
+  it('rebuilds AOT on HTML changes', async () => {
+    const overrides = { watch: true, aot: true };
+
+    let buildCount = 1;
+    const run = await architect.scheduleTarget(target, overrides);
+    await run.output.pipe(
+      debounceTime(1000),
+      tap(() => {
+        const content = virtualFs.fileBufferToString(
+          host.scopedSync().read(join(outputPath, 'main.js')),
+        );
+
+        switch (buildCount) {
+          case 1:
+              expect(content).not.toContain('New Updated Content');
+              host.appendToFile('src/app/app.component.html', 'New Updated Content');
+            break;
+          case 2:
+              expect(content).toContain('New Updated Content');
+            break;
+        }
+
+        buildCount++;
+      }),
+      tap((buildEvent) => expect(buildEvent.success).toBe(true)),
+      take(2),
+    ).toPromise();
+    await run.stop();
+  });
 });

packages/ngtools/webpack/src/compiler_host.ts

@@ -31,11 +31,14 @@ export class WebpackCompilerHost implements ts.CompilerHost {
     '.js.map',
     '.ngfactory.js',
     '.ngfactory.js.map',
-    '.ngstyle.js',
-    '.ngstyle.js.map',
     '.ngsummary.json',
   ];
 
+  private _virtualStyleFileExtensions = [
+    '.shim.ngstyle.js',
+    '.shim.ngstyle.js.map',
+  ];
+
   constructor(
     private _options: ts.CompilerOptions,
     basePath: string,
@@ -110,6 +113,10 @@ export class WebpackCompilerHost implements ts.CompilerHost {
       });
     }
 
+    if (fullPath.endsWith('.ts')) {
+      return;
+    }
+
     // In case resolveJsonModule and allowJs we also need to remove virtual emitted files
     // both if they exists or not.
     if (
@@ -119,6 +126,15 @@ export class WebpackCompilerHost implements ts.CompilerHost {
       if (this._memoryHost.exists(fullPath)) {
         this._memoryHost.delete(fullPath);
       }
+
+      return;
+    }
+
+    for (const ext of this._virtualStyleFileExtensions) {
+      const virtualFile = (fullPath + ext) as Path;
+      if (this._memoryHost.exists(virtualFile)) {
+        this._memoryHost.delete(virtualFile);
+      }
     }
   }