HMR: Don't wait for packaging

packages/core/core/src/ReporterRunner.js

@@ -28,6 +28,8 @@ type Opts = {|
   workerFarm: WorkerFarm,
 |};
 
+const instances: Set<ReporterRunner> = new Set();
+
 export default class ReporterRunner {
   workerFarm: WorkerFarm;
   config: ParcelConfig;
@@ -44,6 +46,7 @@ export default class ReporterRunner {
     logger.onLog(event => this.report(event));
 
     bus.on('reporterEvent', this.eventHandler);
+    instances.add(this);
 
     if (this.options.shouldPatchConsole) {
       patchConsole();
@@ -107,6 +110,7 @@ export default class ReporterRunner {
 
   dispose() {
     bus.off('reporterEvent', this.eventHandler);
+    instances.delete(this);
   }
 }
 
@@ -130,6 +134,6 @@ export function reportWorker(workerApi: WorkerApi, event: ReporterEvent) {
   bus.emit('reporterEvent', event);
 }
 
-export function report(event: ReporterEvent) {
-  bus.emit('reporterEvent', event);
+export async function report(event: ReporterEvent): Promise<void> {
+  await Promise.all([...instances].map(instance => instance.report(event)));
 }

packages/core/core/src/requests/ParcelBuildRequest.js

@@ -14,6 +14,10 @@ import createWriteBundlesRequest from './WriteBundlesRequest';
 import {assertSignalNotAborted} from '../utils';
 import dumpGraphToGraphViz from '../dumpGraphToGraphViz';
 import {bundleGraphEdgeTypes} from '../BundleGraph';
+import {report} from '../ReporterRunner';
+import IBundleGraph from '../public/BundleGraph';
+import {NamedBundle} from '../public/Bundle';
+import {assetFromValue} from '../public/Asset';
 
 type ParcelBuildRequestInput = {|
   optionsRef: SharedReference,
@@ -68,6 +72,23 @@ async function run({input, api, options}: RunInput) {
   // $FlowFixMe Added in Flow 0.121.0 upgrade in #4381 (Windows only)
   dumpGraphToGraphViz(bundleGraph._graph, 'BundleGraph', bundleGraphEdgeTypes);
 
+  await report({
+    type: 'buildProgress',
+    phase: 'bundled',
+    bundleGraph: new IBundleGraph(
+      bundleGraph,
+      (bundle, bundleGraph, options) =>
+        NamedBundle.get(bundle, bundleGraph, options),
+      options,
+    ),
+    changedAssets: new Map(
+      Array.from(changedAssets).map(([id, asset]) => [
+        id,
+        assetFromValue(asset, options),
+      ]),
+    ),
+  });
+
   let writeBundlesRequest = createWriteBundlesRequest({
     bundleGraph,
     optionsRef,

packages/core/core/src/types.js

@@ -529,4 +529,4 @@ export type ValidationOpts = {|
   configCachePath: string,
 |};
 
-export type ReportFn = (event: ReporterEvent) => void;
+export type ReportFn = (event: ReporterEvent) => void | Promise<void>;

packages/core/types/index.js

@@ -1765,6 +1765,13 @@ export type BundlingProgressEvent = {|
   +phase: 'bundling',
 |};
 
+export type BundledProgressEvent = {|
+  +type: 'buildProgress',
+  +phase: 'bundled',
+  +bundleGraph: BundleGraph<NamedBundle>,
+  +changedAssets: Map<string, Asset>,
+|};
+
 /**
  * A new Bundle is being packaged.
  * @section reporter
@@ -1792,6 +1799,7 @@ export type BuildProgressEvent =
   | ResolvingProgressEvent
   | TransformingProgressEvent
   | BundlingProgressEvent
+  | BundledProgressEvent
   | PackagingProgressEvent
   | OptimizingProgressEvent;
 

packages/reporters/dev-server/src/HMRServer.js

@@ -1,12 +1,12 @@
 // @flow
 
 import type {
-  BuildSuccessEvent,
-  Dependency,
-  PluginOptions,
+  Asset,
   BundleGraph,
+  Dependency,
+  NamedBundle,
   PackagedBundle,
-  Asset,
+  PluginOptions,
 } from '@parcel/types';
 import type {Diagnostic} from '@parcel/diagnostic';
 import type {AnsiDiagnosticResult} from '@parcel/utils';
@@ -60,7 +60,8 @@ export default class HMRServer {
   wss: WebSocket.Server;
   unresolvedError: HMRMessage | null = null;
   options: HMRServerOptions;
-  bundleGraph: BundleGraph<PackagedBundle> | null = null;
+  bundleGraph: BundleGraph<PackagedBundle> | BundleGraph<NamedBundle> | null =
+    null;
   stopServer: ?() => Promise<void>;
 
   constructor(options: HMRServerOptions) {
@@ -149,7 +150,11 @@ export default class HMRServer {
     this.broadcast(this.unresolvedError);
   }
 
-  async emitUpdate(event: BuildSuccessEvent) {
+  async emitUpdate(event: {
+    +bundleGraph: BundleGraph<PackagedBundle> | BundleGraph<NamedBundle>,
+    +changedAssets: Map<string, Asset>,
+    ...
+  }) {
     this.unresolvedError = null;
     this.bundleGraph = event.bundleGraph;
 

packages/reporters/dev-server/src/ServerReporter.js

@@ -89,6 +89,11 @@ export default (new Reporter({
           server.buildStart();
         }
         break;
+      case 'buildProgress':
+        if (event.phase === 'bundled' && hmrServer) {
+          await hmrServer.emitUpdate(event);
+        }
+        break;
       case 'buildSuccess':
         if (serveOptions) {
           if (!server) {
@@ -100,9 +105,6 @@ export default (new Reporter({
 
           server.buildSuccess(event.bundleGraph, event.requestBundle);
         }
-        if (hmrServer) {
-          hmrServer.emitUpdate(event);
-        }
         break;
       case 'buildFailure':
         // On buildFailure watchStart sometimes has not been called yet