feat(@angular-devkit/build-angular): add watch mode to server

Author: Fabian Wiles

packages/angular_devkit/build_angular/src/server/index.ts

@@ -85,7 +85,14 @@ export class ServerBuilder implements Builder<BuildWebpackServerSchema> {
  };
 
  try {
- webpackCompiler.run(callback);
+ if (options.watch) {
+ const watching = webpackCompiler.watch({ poll: options.poll }, callback);
+
+ // Teardown logic. Close the watcher when unsubscribed from.
+ return () => watching.close(() => { });
+ } else {
+ webpackCompiler.run(callback);
+ }
  } catch (err) {
  if (err) {
  this.context.logger.error(

packages/angular_devkit/build_angular/src/server/schema.d.ts

@@ -117,6 +117,14 @@ export interface BuildWebpackServerSchema {
  * Use file name for lazy loaded chunks.
  */
  namedChunks?: boolean;
+ /**
+ * Run build when files change.
+ */
+ watch?: boolean;
+ /**
+ * Enable and define the file watching poll time period in milliseconds.
+ */
+ poll?: number;
 }
 
 /**

packages/angular_devkit/build_angular/src/server/schema.json

@@ -157,6 +157,15 @@
  "type": "string"
  },
  "default": []
+ },
+ "watch": {
+ "type": "boolean",
+ "description": "Run build when files change.",
+ "default": false
+ },
+ "poll": {
+ "type": "number",
+ "description": "Enable and define the file watching poll time period in milliseconds."
  }
  },
  "additionalProperties": false,
@@ -202,6 +211,6 @@
  }
  ]
  }
- 
+
  }
 }

packages/angular_devkit/build_angular/test/server/base_spec_large.ts

@@ -45,4 +45,18 @@ describe('Server Builder', () => {
  }),
  ).toPromise().then(done, done.fail);
  }, Timeout.Standard);
+
+ it('runs watch mode', (done) => {
+ const overrides = { watch: true };
+
+ runTargetSpec(host, { project: 'app', target: 'server' }, overrides).pipe(
+ tap((buildEvent) => {
+ expect(buildEvent.success).toBe(true);
+
+ const fileName = join(outputPath, 'main.js');
+ const content = virtualFs.fileBufferToString(host.scopedSync().read(normalize(fileName)));
+ expect(content).toMatch(/AppServerModuleNgFactory/);
+ }),
+ ).subscribe(undefined, done.fail, done);
+ }, Timeout.Standard);
 });