Collect request stats (#9633)

Co-authored-by: mattcompiles <[email protected]>

Author: benjervis

packages/core/core/src/Parcel.js

@@ -360,6 +360,7 @@ export default class Parcel {
               bundleGraph: event.bundleGraph,
               buildTime: 0,
               requestBundle: event.requestBundle,
+              unstable_requestStats: {},
             };
           }
 
@@ -383,6 +384,7 @@ export default class Parcel {
 
           return result;
         },
+        unstable_requestStats: this.#requestTracker.flushStats(),
       };
 
       await this.#reporterRunner.report(event);
@@ -400,6 +402,7 @@ export default class Parcel {
       let event = {
         type: 'buildFailure',
         diagnostics: Array.isArray(diagnostic) ? diagnostic : [diagnostic],
+        unstable_requestStats: this.#requestTracker.flushStats(),
       };
 
       await this.#reporterRunner.report(event);

packages/core/core/src/RequestTracker.js

@@ -164,6 +164,7 @@ export const requestTypes = {
 };
 
 type RequestType = $Values<typeof requestTypes>;
+type RequestTypeName = $Keys<typeof requestTypes>;
 
 type RequestGraphNode =
   | RequestNode
@@ -1027,6 +1028,7 @@ export default class RequestTracker {
   farm: WorkerFarm;
   options: ParcelOptions;
   signal: ?AbortSignal;
+  stats: Map<RequestType, number> = new Map();
 
   constructor({
     graph,
@@ -1205,6 +1207,9 @@ export default class RequestTracker {
 
     try {
       let node = this.graph.getRequestNode(requestNodeId);
+
+      this.stats.set(request.type, (this.stats.get(request.type) ?? 0) + 1);
+
       let result = await request.run({
         input: request.input,
         api,
@@ -1227,6 +1232,25 @@ export default class RequestTracker {
     }
   }
 
+  flushStats(): {[requestType: string]: number} {
+    let requestTypeEntries = {};
+
+    for (let key of (Object.keys(requestTypes): RequestTypeName[])) {
+      requestTypeEntries[requestTypes[key]] = key;
+    }
+
+    let formattedStats = {};
+
+    for (let [requestType, count] of this.stats.entries()) {
+      let requestTypeName = requestTypeEntries[requestType];
+      formattedStats[requestTypeName] = count;
+    }
+
+    this.stats = new Map();
+
+    return formattedStats;
+  }
+
   createAPI<TResult>(
     requestId: NodeId,
     previousInvalidations: Array<RequestInvalidation>,

packages/core/core/src/requests/AssetGraphRequest.js

@@ -16,6 +16,7 @@ import type {StaticRunOpts, RunAPI} from '../RequestTracker';
 import type {EntryResult} from './EntryRequest';
 import type {PathRequestInput} from './PathRequest';
 import type {Diagnostic} from '@parcel/diagnostic';
+import logger from '@parcel/logger';
 
 import invariant from 'assert';
 import nullthrows from 'nullthrows';
@@ -200,7 +201,9 @@ export class AssetGraphBuilder {
       'A root node is required to traverse',
     );
 
+    let visitedAssetGroups = new Set();
     let visited = new Set([rootNodeId]);
+
     const visit = (nodeId: NodeId) => {
       if (errors.length > 0) {
         return;
@@ -223,6 +226,10 @@ export class AssetGraphBuilder {
           (!visited.has(childNodeId) || child.hasDeferred) &&
           this.shouldVisitChild(nodeId, childNodeId)
         ) {
+          if (child.type === 'asset_group') {
+            visitedAssetGroups.add(childNodeId);
+          }
+
           visited.add(childNodeId);
           visit(childNodeId);
         }
@@ -232,6 +239,14 @@ export class AssetGraphBuilder {
     visit(rootNodeId);
     await this.queue.run();
 
+    logger.verbose({
+      origin: '@parcel/core',
+      message: 'Asset graph walked',
+      meta: {
+        visitedAssetGroupsCount: visitedAssetGroups.size,
+      },
+    });
+
     if (this.prevChangedAssetsPropagation) {
       // Add any previously seen Assets that have not been propagated yet to
       // 'this.changedAssetsPropagation', but only if they still remain in the graph

packages/core/types-internal/src/index.js

@@ -1976,6 +1976,7 @@ export type BuildSuccessEvent = {|
   +buildTime: number,
   +changedAssets: Map<string, Asset>,
   +requestBundle: (bundle: NamedBundle) => Promise<BuildSuccessEvent>,
+  +unstable_requestStats: {[requestType: string]: number},
 |};
 
 /**
@@ -1985,6 +1986,7 @@ export type BuildSuccessEvent = {|
 export type BuildFailureEvent = {|
   +type: 'buildFailure',
   +diagnostics: Array<Diagnostic>,
+  +unstable_requestStats: {[requestType: string]: number},
 |};
 
 /**

packages/reporters/tracer/src/TracerReporter.js

@@ -66,14 +66,14 @@ export default (new Reporter({
       case 'buildSuccess':
       case 'buildFailure':
         nullthrows(tracer).flush();
+        tracer = null;
         // We explicitly trigger `end` on the writeStream for the trace, then we need to wait for
         // the `close` event before resolving the promise this report function returns to ensure
         // that the file has been properly closed and moved from it's temp location before Parcel
         // shuts down.
         return new Promise((resolve, reject) => {
           nullthrows(writeStream).once('close', err => {
             writeStream = null;
-            tracer = null;
             if (err) {
               reject(err);
             } else {