fix some incorrect properties accesses

fix some edge cases with MultiCompiler

fixes #12770

lib/MultiCompiler.js

@@ -350,6 +350,12 @@ module.exports = class MultiCompiler {
 		let errored = false;
 		let running = 0;
 		const parallelism = this._options.parallelism;
+		/**
+		 * @param {Node} node node
+		 * @param {Error=} err error
+		 * @param {Stats=} stats result
+		 * @returns {void}
+		 */
 		const nodeDone = (node, err, stats) => {
 			if (errored) return;
 			if (err) {
@@ -367,27 +373,35 @@ module.exports = class MultiCompiler {
 				);
 			}
 			node.result = stats;
+			running--;
 			if (node.state === "running") {
-				running--;
 				node.state = "done";
-				for (const child of node.children) {
-					if (child.state !== "blocked") continue;
-					if (child.parents.every(p => p.state === "done")) {
-						child.state = "queued";
-						queue.enqueue(child);
-					}
-				}
-				process.nextTick(processQueue);
 			}
+			for (const child of node.children) {
+				if (child.state !== "blocked") continue;
+				if (child.parents.every(p => p.state === "done")) {
+					child.state = "queued";
+					queue.enqueue(child);
+				}
+			}
+			process.nextTick(processQueue);
 		};
+		/**
+		 * @param {Node} node node
+		 * @returns {void}
+		 */
 		const nodeInvalid = node => {
-			if (node.state === "done") {
+			if (node.state === "done" || node.state === "running") {
 				node.state = "blocked";
-				for (const child of node.children) {
-					nodeInvalid(child);
-				}
+			}
+			for (const child of node.children) {
+				nodeInvalid(child);
 			}
 		};
+		/**
+		 * @param {Node} node node
+		 * @returns {void}
+		 */
 		const nodeChange = node => {
 			nodeInvalid(node);
 			if (
@@ -415,6 +429,7 @@ module.exports = class MultiCompiler {
 		const processQueue = () => {
 			while (running < parallelism && queue.length > 0 && !errored) {
 				const node = queue.dequeue();
+				if (node.state !== "queued") continue;
 				running++;
 				node.state = "running";
 				run(node.compiler, nodeDone.bind(null, node));
@@ -446,6 +461,7 @@ module.exports = class MultiCompiler {
 		if (this.running) {
 			return handler(new ConcurrentCompilationError());
 		}
+		this.running = true;
 
 		if (this.validateDependencies(handler)) {
 			const watchings = this._runGraph(
@@ -480,6 +496,7 @@ module.exports = class MultiCompiler {
 		if (this.running) {
 			return callback(new ConcurrentCompilationError());
 		}
+		this.running = true;
 
 		if (this.validateDependencies(callback)) {
 			this._runGraph(

lib/Watching.js

@@ -54,7 +54,6 @@ class Watching {
 		this.running = false;
 		this._initial = true;
 		this._needRecords = true;
-		this._needWatcherInfo = false;
 		this.watcher = undefined;
 		this.pausedWatcher = undefined;
 		this._done = this._done.bind(this);
@@ -84,21 +83,6 @@ class Watching {
 				});
 			}
 			this.invalid = false;
-			if (this._needWatcherInfo) {
-				this._needWatcherInfo = false;
-				const watcher = this.pausedWatcher;
-				if (watcher) {
-					this.compiler.modifiedFiles = watcher.aggregatedChanges;
-					this.compiler.removedFiles = watcher.aggregatedRemovals;
-					this.compiler.fileTimestamps = watcher.getFileTimeInfoEntries();
-					this.compiler.contextTimestamps = watcher.getContextTimeInfoEntries();
-				} else {
-					this.compiler.modifiedFiles = undefined;
-					this.compiler.removedFiles = undefined;
-					this.compiler.fileTimestamps = undefined;
-					this.compiler.contextTimestamps = undefined;
-				}
-			}
 			this.compiler.hooks.watchRun.callAsync(this.compiler, err => {
 				if (err) return this._done(err);
 				const onCompiled = (err, compilation) => {
@@ -277,6 +261,11 @@ class Watching {
 				this.compiler.contextTimestamps = contextTimeInfoEntries;
 				this.compiler.removedFiles = removedFiles;
 				this.compiler.modifiedFiles = changedFiles;
+				if (this.watcher) {
+					this.pausedWatcher = this.watcher;
+					this.watcher.pause();
+					this.watcher = null;
+				}
 				this._invalidate();
 				this._onChange();
 			},
@@ -297,7 +286,6 @@ class Watching {
 		}
 		if (!this._initial) {
 			this.compiler.hooks.invalid.call(null, Date.now());
-			this._needWatcherInfo = true;
 		}
 		this._invalidate();
 	}
@@ -309,6 +297,14 @@ class Watching {
 			return;
 		}
 		if (this.watcher) {
+			this.compiler.modifiedFiles =
+				this.watcher.getAggregatedChanges &&
+				this.watcher.getAggregatedChanges();
+			this.compiler.removedFiles =
+				this.watcher.getAggregatedRemovals &&
+				this.watcher.getAggregatedRemovals();
+			this.compiler.fileTimestamps = this.watcher.getFileTimeInfoEntries();
+			this.compiler.contextTimestamps = this.watcher.getContextTimeInfoEntries();
 			this.pausedWatcher = this.watcher;
 			this.watcher.pause();
 			this.watcher = null;
@@ -328,7 +324,6 @@ class Watching {
 	resume() {
 		if (this.suspended) {
 			this.suspended = false;
-			this._needWatcherInfo = true;
 			this._invalidate();
 		}
 	}

lib/node/NodeWatchFileSystem.js

@@ -98,6 +98,12 @@ class NodeWatchFileSystem {
 					this.watcher.pause();
 				}
 			},
+			getAggregatedRemovals: () => {
+				return this.watcher && this.watcher.aggregatedRemovals;
+			},
+			getAggregatedChanges: () => {
+				return this.watcher && this.watcher.aggregatedChanges;
+			},
 			getFileTimeInfoEntries: () => {
 				if (this.watcher) {
 					return this.watcher.getTimeInfoEntries();

lib/util/fs.js

@@ -64,6 +64,8 @@ const path = require("path");
  * @typedef {Object} Watcher
  * @property {function(): void} close closes the watcher and all underlying file watchers
  * @property {function(): void} pause closes the watcher, but keeps underlying file watchers alive until the next watch call
+ * @property {function(): Set<string>=} getAggregatedChanges get current aggregated changes that have not yet send to callback
+ * @property {function(): Set<string>=} getAggregatedRemovals get current aggregated removals that have not yet send to callback
  * @property {function(): Map<string, FileSystemInfoEntry | "ignore">} getFileTimeInfoEntries get info about files
  * @property {function(): Map<string, FileSystemInfoEntry | "ignore">} getContextTimeInfoEntries get info about directories
  */

test/MultiCompiler.test.js

@@ -270,6 +270,8 @@ describe("MultiCompiler", function () {
 							c:
 							  c compiled successfully"
 					`);
+					expect(compiler.compilers[0].modifiedFiles).toBe(undefined);
+					expect(compiler.compilers[0].removedFiles).toBe(undefined);
 					expect(events).toMatchInlineSnapshot(`
 							Array [
 							  "b run",
@@ -295,6 +297,8 @@ describe("MultiCompiler", function () {
 				b:
 				  b compiled successfully"
 			`);
+					expect(compiler.compilers[1].modifiedFiles).toEqual(new Set());
+					expect(compiler.compilers[1].removedFiles).toEqual(new Set());
 					expect(events).toMatchInlineSnapshot(`
 				Array [
 				  "b run",

types.d.ts

@@ -10786,6 +10786,16 @@ declare interface Watcher {
 	 */
 	pause: () => void;
 
+	/**
+	 * get current aggregated changes that have not yet send to callback
+	 */
+	getAggregatedChanges?: () => Set<string>;
+
+	/**
+	 * get current aggregated removals that have not yet send to callback
+	 */
+	getAggregatedRemovals?: () => Set<string>;
+
 	/**
 	 * get info about files
 	 */