store build dependencies snapshot in pack

add snapshot shortcut for package manager managed paths
add cache.managedPaths

declarations.d.ts

@@ -8,6 +8,12 @@ declare namespace NodeJS {
 }
 
 declare module "neo-async" {
+	interface QueueObject<T, E> {
+		push(item: T): void;
+		drain: () => void;
+		error: (err: E) => void;
+	}
+
 	export interface Dictionary<T> {
 		[key: string]: T;
 	}
@@ -104,6 +110,11 @@ declare module "neo-async" {
 		callback?: AsyncResultObjectCallback<T, E>
 	): void;
 
+	export function queue<T, E>(
+		worker: AsyncFunction<T, E>,
+		concurrency?: number
+	): QueueObject<T, E>;
+
 	export const forEach: typeof each;
 	export const forEachLimit: typeof eachLimit;
 }

declarations/WebpackOptions.d.ts

@@ -441,6 +441,10 @@ export interface WebpackOptions {
  * via the `definition` "MemoryCacheOptions".
  */
 export interface MemoryCacheOptions {
+	/**
+	 * List of paths that are managed by a package manager and can be trusted to not being modified otherwise
+	 */
+	managedPaths?: string[];
 	/**
 	 * In memory caching
 	 */
@@ -480,6 +484,10 @@ export interface FileCacheOptions {
 	 * Time in ms after which idle period the initial cache storing should happen (only for store: 'pack' or 'idle')
 	 */
 	idleTimeoutForInitialStore?: number;
+	/**
+	 * List of paths that are managed by a package manager and can be trusted to not being modified otherwise
+	 */
+	managedPaths?: string[];
 	/**
 	 * Name for the cache. Different names will lead to different coexisting caches.
 	 */

examples/persistent-caching/README.md

@@ -3,6 +3,7 @@
 ```javascript
 console.log(process.env.NODE_ENV);
 
+import "./example.css";
 import "react";
 import "react-dom";
 import "acorn";
@@ -17,13 +18,31 @@ const path = require("path");
 module.exports = (env = "development") => ({
 	mode: env,
 	infrastructureLogging: {
+		// Optional: print more verbose logging about caching
 		level: "verbose"
 	},
 	cache: {
 		type: "filesystem",
+
 		// changing the cacheDirectory is optional,
 		// by default it will be in `node_modules/.cache`
-		cacheDirectory: path.resolve(__dirname, ".cache")
+		cacheDirectory: path.resolve(__dirname, ".cache"),
+
+		// Add additional dependencies to the build
+		buildDependencies: {
+			// recommended to invalidate cache on config changes
+			// This also makes all dependencies of this file build dependencies
+			config: [__filename]
+			// By default webpack and loaders are build dependencies
+		}
+	},
+	module: {
+		rules: [
+			{
+				test: /\.css$/,
+				use: ["style-loader", "css-loader"]
+			}
+		]
 	}
 });
 ```
@@ -33,10 +52,10 @@ module.exports = (env = "development") => ({
 ```
 Hash: 0a1b2c3d4e5f6a7b8c9d
 Version: webpack 5.0.0-alpha.19
-    Asset      Size  Chunks             Chunk Names
-output.js  1.78 MiB     {0}  [emitted]  main
+    Asset     Size  Chunks             Chunk Names
+output.js  1.8 MiB     {0}  [emitted]  main
 Entrypoint main = output.js
-chunk {0} output.js (main) 1.54 MiB (javascript) 1.07 KiB (runtime) [entry]
+chunk {0} output.js (main) 1.55 MiB (javascript) 1.07 KiB (runtime) [entry]
     > ./example.js main
-    526 chunk modules
+    530 chunk modules
 ```

examples/persistent-caching/example.css

@@ -0,0 +1,3 @@
+body {
+	background: red;
+}

examples/persistent-caching/example.js

@@ -1,5 +1,6 @@
 console.log(process.env.NODE_ENV);
 
+import "./example.css";
 import "react";
 import "react-dom";
 import "acorn";

examples/persistent-caching/webpack.config.js

@@ -2,12 +2,30 @@ const path = require("path");
 module.exports = (env = "development") => ({
 	mode: env,
 	infrastructureLogging: {
+		// Optional: print more verbose logging about caching
 		level: "verbose"
 	},
 	cache: {
 		type: "filesystem",
+
 		// changing the cacheDirectory is optional,
 		// by default it will be in `node_modules/.cache`
-		cacheDirectory: path.resolve(__dirname, ".cache")
+		cacheDirectory: path.resolve(__dirname, ".cache"),
+
+		// Add additional dependencies to the build
+		buildDependencies: {
+			// recommended to invalidate cache on config changes
+			// This also makes all dependencies of this file build dependencies
+			config: [__filename]
+			// By default webpack and loaders are build dependencies
+		}
+	},
+	module: {
+		rules: [
+			{
+				test: /\.css$/,
+				use: ["style-loader", "css-loader"]
+			}
+		]
 	}
 });

lib/Compilation.js

@@ -414,7 +414,9 @@ class Compilation {
 		this.compiler = compiler;
 		this.resolverFactory = compiler.resolverFactory;
 		this.inputFileSystem = compiler.inputFileSystem;
-		this.fileSystemInfo = new FileSystemInfo(this.inputFileSystem);
+		this.fileSystemInfo = new FileSystemInfo(this.inputFileSystem, {
+			managedPaths: compiler.managedPaths
+		});
 		if (compiler.fileTimestamps) {
 			this.fileSystemInfo.addFileTimestamps(compiler.fileTimestamps);
 		}

lib/Compiler.js

@@ -176,6 +176,8 @@ class Compiler {
 		this.recordsOutputPath = null;
 		this.records = {};
 		/** @type {Set<string>} */
+		this.managedPaths = new Set();
+		/** @type {Set<string>} */
 		this.removedFiles = new Set();
 		/** @type {Map<string, FileSystemInfoEntry | null>} */
 		this.fileTimestamps = new Map();