add "snapshot" configuration to allow to configure how snapshots are created

expose snapshot options for module, resolve, buildDependencies and resolveBuildDependencies
move managedPaths and immutablePaths from config.cache to config.snapshot
add timestamp + hash snapshotting mode
use timestamp + hash mode by default in production and for buildDependencies

declarations/WebpackOptions.d.ts

@@ -679,6 +679,10 @@ export interface WebpackOptions {
 	 * Options for the resolver when resolving loaders.
 	 */
 	resolveLoader?: ResolveLoader;
+	/**
+	 * Options affecting how file system snapshots are created and validated.
+	 */
+	snapshot?: SnapshotOptions;
 	/**
 	 * Stats options object or preset name.
 	 */
@@ -700,14 +704,6 @@ export interface WebpackOptions {
  * Options object for in-memory caching.
  */
 export interface MemoryCacheOptions {
-	/**
-	 * List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.
-	 */
-	immutablePaths?: string[];
-	/**
-	 * List of paths that are managed by a package manager and can be trusted to not be modified otherwise.
-	 */
-	managedPaths?: string[];
 	/**
 	 * In memory caching.
 	 */
@@ -1751,6 +1747,71 @@ export interface PerformanceOptions {
 	 */
 	maxEntrypointSize?: number;
 }
+/**
+ * Options affecting how file system snapshots are created and validated.
+ */
+export interface SnapshotOptions {
+	/**
+	 * Options for snapshotting build dependencies to determine if the whole cache need to be invalidated.
+	 */
+	buildDependencies?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+	/**
+	 * List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.
+	 */
+	immutablePaths?: string[];
+	/**
+	 * List of paths that are managed by a package manager and can be trusted to not be modified otherwise.
+	 */
+	managedPaths?: string[];
+	/**
+	 * Options for snapshotting dependencies of modules to determine if they need to be built again.
+	 */
+	module?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+	/**
+	 * Options for snapshotting dependencies of request resolving to determine if requests need to be re-resolved.
+	 */
+	resolve?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+	/**
+	 * Options for snapshotting the resolving of build dependencies to determine if the build dependencies need to be re-resolved.
+	 */
+	resolveBuildDependencies?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+}
 /**
  * Stats options object.
  */
@@ -2303,6 +2364,10 @@ export interface WebpackOptionsNormalized {
 	 * Options for the resolver when resolving loaders.
 	 */
 	resolveLoader: ResolveLoader;
+	/**
+	 * Options affecting how file system snapshots are created and validated.
+	 */
+	snapshot: SnapshotOptions;
 	/**
 	 * Stats options object or preset name.
 	 */

lib/ContextModule.js

@@ -81,6 +81,8 @@ const makeSerializable = require("./util/makeSerializable");
  * @param {ResolveDependenciesCallback} callback
  */
 
+const SNAPSHOT_OPTIONS = { timestamp: true };
+
 const TYPES = new Set(["javascript"]);
 
 class ContextModule extends Module {
@@ -428,7 +430,7 @@ class ContextModule extends Module {
 				null,
 				[this.context],
 				null,
-				{},
+				SNAPSHOT_OPTIONS,
 				(err, snapshot) => {
 					if (err) return callback(err);
 					this.buildInfo.snapshot = snapshot;

lib/NormalModule.js

@@ -804,7 +804,8 @@ class NormalModule extends Module {
 			};
 
 			const handleBuildDone = () => {
-				if (!this.buildInfo.cacheable) {
+				const snapshotOptions = compilation.options.snapshot.module;
+				if (!this.buildInfo.cacheable || !snapshotOptions) {
 					return callback();
 				}
 				// convert file/context/missingDependencies into filesystem snapshot
@@ -813,7 +814,7 @@ class NormalModule extends Module {
 					this.buildInfo.fileDependencies,
 					this.buildInfo.contextDependencies,
 					this.buildInfo.missingDependencies,
-					null,
+					snapshotOptions,
 					(err, snapshot) => {
 						if (err) {
 							this.markModuleAsErrored(err);

lib/WebpackOptionsApply.js

@@ -490,13 +490,14 @@ class WebpackOptionsApply extends OptionsApply {
 
 		new WarnCaseSensitiveModulesPlugin().apply(compiler);
 
+		const AddManagedPathsPlugin = require("./cache/AddManagedPathsPlugin");
+		new AddManagedPathsPlugin(
+			options.snapshot.managedPaths,
+			options.snapshot.immutablePaths
+		).apply(compiler);
+
 		if (options.cache && typeof options.cache === "object") {
 			const cacheOptions = options.cache;
-			const AddManagedPathsPlugin = require("./cache/AddManagedPathsPlugin");
-			new AddManagedPathsPlugin(
-				cacheOptions.managedPaths,
-				cacheOptions.immutablePaths
-			).apply(compiler);
 			switch (cacheOptions.type) {
 				case "memory": {
 					const MemoryCachePlugin = require("./cache/MemoryCachePlugin");
@@ -525,8 +526,7 @@ class WebpackOptionsApply extends OptionsApply {
 									logger: compiler.getInfrastructureLogger(
 										"webpack.cache.PackFileCacheStrategy"
 									),
-									managedPaths: cacheOptions.managedPaths,
+									snapshot: options.snapshot
-									immutablePaths: cacheOptions.immutablePaths
 								}),
 								cacheOptions.idleTimeout,
 								cacheOptions.idleTimeoutForInitialStore

lib/cache/PackFileCacheStrategy.js

@@ -13,6 +13,7 @@ const makeSerializable = require("../util/makeSerializable");
 const memorize = require("../util/memorize");
 const { createFileSerializer } = require("../util/serialization");
 
+/** @typedef {import("../../declarations/WebpackOptions").SnapshotOptions} SnapshotOptions */
 /** @typedef {import("../Cache").Etag} Etag */
 /** @typedef {import("../Compiler")} Compiler */
 /** @typedef {import("../FileSystemInfo").Snapshot} Snapshot */
@@ -721,8 +722,7 @@ class PackFileCacheStrategy {
 	 * @param {string} options.cacheLocation the location of the cache data
 	 * @param {string} options.version version identifier
 	 * @param {Logger} options.logger a logger
-	 * @param {Iterable<string>} options.managedPaths paths managed only by package manager
+	 * @param {SnapshotOptions} options.snapshot options regarding snapshotting
-	 * @param {Iterable<string>} options.immutablePaths immutable paths
 	 */
 	constructor({
 		compiler,
@@ -731,13 +731,12 @@ class PackFileCacheStrategy {
 		cacheLocation,
 		version,
 		logger,
-		managedPaths,
+		snapshot
-		immutablePaths
 	}) {
 		this.fileSerializer = createFileSerializer(fs);
 		this.fileSystemInfo = new FileSystemInfo(fs, {
-			managedPaths,
+			managedPaths: snapshot.managedPaths,
-			immutablePaths,
+			immutablePaths: snapshot.immutablePaths,
 			logger: logger.getChildLogger("webpack.FileSystemInfo")
 		});
 		this.compiler = compiler;
@@ -745,6 +744,7 @@ class PackFileCacheStrategy {
 		this.cacheLocation = cacheLocation;
 		this.version = version;
 		this.logger = logger;
+		this.snapshot = snapshot;
 		/** @type {Set<string>} */
 		this.buildDependencies = new Set();
 		/** @type {LazySet<string>} */
@@ -996,17 +996,19 @@ class PackFileCacheStrategy {
 								} else {
 									this.resolveResults = resolveResults;
 								}
-								if (reportProgress)
+								if (reportProgress) {
 									reportProgress(
 										0.6,
-										"snapshot build dependencies (timestamps)"
+										"snapshot build dependencies",
+										"resolving"
 									);
+								}
 								this.fileSystemInfo.createSnapshot(
 									undefined,
 									resolveDependencies.files,
 									resolveDependencies.directories,
 									resolveDependencies.missing,
-									{},
+									this.snapshot.resolveBuildDependencies,
 									(err, snapshot) => {
 										if (err) {
 											this.logger.timeEnd("snapshot build dependencies");
@@ -1026,17 +1028,19 @@ class PackFileCacheStrategy {
 										} else {
 											this.resolveBuildDependenciesSnapshot = snapshot;
 										}
-										if (reportProgress)
+										if (reportProgress) {
 											reportProgress(
 												0.7,
-												"snapshot build dependencies (hashes)"
+												"snapshot build dependencies",
+												"modules"
 											);
+										}
 										this.fileSystemInfo.createSnapshot(
 											undefined,
 											files,
 											directories,
 											missing,
-											{ hash: true },
+											this.snapshot.buildDependencies,
 											(err, snapshot) => {
 												this.logger.timeEnd("snapshot build dependencies");
 												if (err) return reject(err);

lib/cache/ResolverCachePlugin.js

@@ -79,11 +79,13 @@ class ResolverCachePlugin {
 		const cache = compiler.getCache("ResolverCachePlugin");
 		/** @type {FileSystemInfo} */
 		let fileSystemInfo;
+		let snapshotOptions;
 		let realResolves = 0;
 		let cachedResolves = 0;
 		let cacheInvalidResolves = 0;
 		let concurrentResolves = 0;
 		compiler.hooks.thisCompilation.tap("ResolverCachePlugin", compilation => {
+			snapshotOptions = compilation.options.snapshot.resolve;
 			fileSystemInfo = compilation.fileSystemInfo;
 			compilation.hooks.finishModules.tap("ResolverCachePlugin", () => {
 				if (realResolves + cachedResolves > 0) {
@@ -151,7 +153,7 @@ class ResolverCachePlugin {
 						fileDependencies,
 						contextDependencies,
 						missingDependencies,
-						{ timestamp: true },
+						snapshotOptions,
 						(err, snapshot) => {
 							if (err) return callback(err);
 							if (!snapshot) {

lib/config/defaults.js

@@ -23,6 +23,7 @@ const { cleverMerge } = require("../util/cleverMerge");
 /** @typedef {import("../../declarations/WebpackOptions").Performance} Performance */
 /** @typedef {import("../../declarations/WebpackOptions").ResolveOptions} ResolveOptions */
 /** @typedef {import("../../declarations/WebpackOptions").RuleSetRules} RuleSetRules */
+/** @typedef {import("../../declarations/WebpackOptions").SnapshotOptions} SnapshotOptions */
 /** @typedef {import("../../declarations/WebpackOptions").Target} Target */
 /** @typedef {import("../../declarations/WebpackOptions").WebpackOptionsNormalized} WebpackOptions */
 
@@ -148,6 +149,8 @@ const applyWebpackOptionsDefaults = options => {
 	});
 	const cache = !!options.cache;
 
+	applySnapshotDefaults(options.snapshot, { production });
+
 	applyExperimentsDefaults(options.experiments);
 
 	applyModuleDefaults(options.module, {
@@ -267,7 +270,16 @@ const applyCacheDefaults = (cache, { name, mode }) => {
 			]);
 			break;
 	}
-	A(cache, "managedPaths", () => {
+};
+
+/**
+ * @param {SnapshotOptions} snapshot options
+ * @param {Object} options options
+ * @param {boolean} options.production is production
+ * @returns {void}
+ */
+const applySnapshotDefaults = (snapshot, { production }) => {
+	A(snapshot, "managedPaths", () => {
 		if (process.versions.pnp === "3") {
 			const match = /^(.+?)[\\/]cache[\\/]watchpack-npm-[^\\/]+\.zip[\\/]node_modules[\\/]/.exec(
 				require.resolve("watchpack")
@@ -286,7 +298,7 @@ const applyCacheDefaults = (cache, { name, mode }) => {
 		}
 		return [];
 	});
-	A(cache, "immutablePaths", () => {
+	A(snapshot, "immutablePaths", () => {
 		if (process.versions.pnp === "1") {
 			const match = /^(.+?[\\/]v4)[\\/]npm-watchpack-[^\\/]+-[\da-f]{40}[\\/]node_modules[\\/]/.exec(
 				require.resolve("watchpack")
@@ -304,6 +316,17 @@ const applyCacheDefaults = (cache, { name, mode }) => {
 		}
 		return [];
 	});
+	F(snapshot, "resolveBuildDependencies", () => ({
+		timestamp: true,
+		hash: true
+	}));
+	F(snapshot, "buildDependencies", () => ({ timestamp: true, hash: true }));
+	F(snapshot, "module", () =>
+		production ? { timestamp: true, hash: true } : { timestamp: true }
+	);
+	F(snapshot, "resolve", () =>
+		production ? { timestamp: true, hash: true } : { timestamp: true }
+	);
 };
 
 /**

lib/config/normalization.js

@@ -115,10 +115,6 @@ const getNormalizedWebpackOptions = config => {
 						hashAlgorithm: cache.hashAlgorithm,
 						idleTimeout: cache.idleTimeout,
 						idleTimeoutForInitialStore: cache.idleTimeoutForInitialStore,
-						immutablePaths: optionalNestedArray(cache.immutablePaths, p => [
-							...p
-						]),
-						managedPaths: optionalNestedArray(cache.managedPaths, p => [...p]),
 						name: cache.name,
 						store: cache.store,
 						version: cache.version
@@ -126,11 +122,7 @@ const getNormalizedWebpackOptions = config => {
 				case undefined:
 				case "memory":
 					return {
-						type: "memory",
+						type: "memory"
-						immutablePaths: optionalNestedArray(cache.immutablePaths, p => [
-							...p
-						]),
-						managedPaths: optionalNestedArray(cache.managedPaths, p => [...p])
 					};
 				default:
 					// @ts-expect-error Property 'type' does not exist on type 'never'. ts(2339)
@@ -307,6 +299,32 @@ const getNormalizedWebpackOptions = config => {
 		resolveLoader: nestedConfig(config.resolveLoader, resolve => ({
 			...resolve
 		})),
+		snapshot: nestedConfig(config.snapshot, snapshot => ({
+			resolveBuildDependencies: optionalNestedConfig(
+				snapshot.resolveBuildDependencies,
+				resolveBuildDependencies => ({
+					timestamp: resolveBuildDependencies.timestamp,
+					hash: resolveBuildDependencies.hash
+				})
+			),
+			buildDependencies: optionalNestedConfig(
+				snapshot.buildDependencies,
+				buildDependencies => ({
+					timestamp: buildDependencies.timestamp,
+					hash: buildDependencies.hash
+				})
+			),
+			resolve: optionalNestedConfig(snapshot.resolve, resolve => ({
+				timestamp: resolve.timestamp,
+				hash: resolve.hash
+			})),
+			module: optionalNestedConfig(snapshot.module, module => ({
+				timestamp: module.timestamp,
+				hash: module.hash
+			})),
+			immutablePaths: optionalNestedArray(snapshot.immutablePaths, p => [...p]),
+			managedPaths: optionalNestedArray(snapshot.managedPaths, p => [...p])
+		})),
 		stats: nestedConfig(config.stats, stats => {
 			if (stats === false) {
 				return {

lib/validateSchema.js

@@ -23,6 +23,8 @@ const DID_YOU_MEAN = {
 	pathinfo: "output.pathinfo",
 	pathInfo: "output.pathinfo",
 	splitChunks: "optimization.splitChunks",
+	immutablePaths: "snapshot.immutablePaths",
+	managedPaths: "snapshot.managedPaths",
 	hashedModuleIds:
 		'optimization.moduleIds: "hashed" (BREAKING CHANGE since webpack 5)',
 	namedChunks:

schemas/WebpackOptions.json

@@ -854,26 +854,6 @@
       "type": "object",
       "additionalProperties": false,
       "properties": {
-        "immutablePaths": {
-          "description": "List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.",
-          "type": "array",
-          "items": {
-            "description": "A path to a immutable directory (usually a package manager cache directory).",
-            "type": "string",
-            "absolutePath": true,
-            "minLength": 1
-          }
-        },
-        "managedPaths": {
-          "description": "List of paths that are managed by a package manager and can be trusted to not be modified otherwise.",
-          "type": "array",
-          "items": {
-            "description": "A path to a managed directory (usually a node_modules directory).",
-            "type": "string",
-            "absolutePath": true,
-            "minLength": 1
-          }
-        },
         "type": {
           "description": "In memory caching.",
           "enum": ["memory"]
@@ -2802,6 +2782,93 @@
       "description": "This option enables loading async chunks via a custom script type, such as script type=\"module\".",
       "enum": [false, "text/javascript", "module"]
     },
+    "SnapshotOptions": {
+      "description": "Options affecting how file system snapshots are created and validated.",
+      "type": "object",
+      "additionalProperties": false,
+      "properties": {
+        "buildDependencies": {
+          "description": "Options for snapshotting build dependencies to determine if the whole cache need to be invalidated.",
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "hash": {
+              "description": "Use hashes of the content of the files/directories to determine invalidation.",
+              "type": "boolean"
+            },
+            "timestamp": {
+              "description": "Use timestamps of the files/directories to determine invalidation.",
+              "type": "boolean"
+            }
+          }
+        },
+        "immutablePaths": {
+          "description": "List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.",
+          "type": "array",
+          "items": {
+            "description": "A path to a immutable directory (usually a package manager cache directory).",
+            "type": "string",
+            "absolutePath": true,
+            "minLength": 1
+          }
+        },
+        "managedPaths": {
+          "description": "List of paths that are managed by a package manager and can be trusted to not be modified otherwise.",
+          "type": "array",
+          "items": {
+            "description": "A path to a managed directory (usually a node_modules directory).",
+            "type": "string",
+            "absolutePath": true,
+            "minLength": 1
+          }
+        },
+        "module": {
+          "description": "Options for snapshotting dependencies of modules to determine if they need to be built again.",
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "hash": {
+              "description": "Use hashes of the content of the files/directories to determine invalidation.",
+              "type": "boolean"
+            },
+            "timestamp": {
+              "description": "Use timestamps of the files/directories to determine invalidation.",
+              "type": "boolean"
+            }
+          }
+        },
+        "resolve": {
+          "description": "Options for snapshotting dependencies of request resolving to determine if requests need to be re-resolved.",
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "hash": {
+              "description": "Use hashes of the content of the files/directories to determine invalidation.",
+              "type": "boolean"
+            },
+            "timestamp": {
+              "description": "Use timestamps of the files/directories to determine invalidation.",
+              "type": "boolean"
+            }
+          }
+        },
+        "resolveBuildDependencies": {
+          "description": "Options for snapshotting the resolving of build dependencies to determine if the build dependencies need to be re-resolved.",
+          "type": "object",
+          "additionalProperties": false,
+          "properties": {
+            "hash": {
+              "description": "Use hashes of the content of the files/directories to determine invalidation.",
+              "type": "boolean"
+            },
+            "timestamp": {
+              "description": "Use timestamps of the files/directories to determine invalidation.",
+              "type": "boolean"
+            }
+          }
+        }
+      }
+    },
     "SourceMapFilename": {
       "description": "The filename of the SourceMaps for the JavaScript files. They are inside the `output.path` directory.",
       "type": "string",
@@ -3308,6 +3375,9 @@
         "resolveLoader": {
           "$ref": "#/definitions/ResolveLoader"
         },
+        "snapshot": {
+          "$ref": "#/definitions/SnapshotOptions"
+        },
         "stats": {
           "$ref": "#/definitions/StatsValue"
         },
@@ -3323,6 +3393,7 @@
       },
       "required": [
         "cache",
+        "snapshot",
         "entry",
         "experiments",
         "externals",
@@ -3445,6 +3516,9 @@
     "resolveLoader": {
       "$ref": "#/definitions/ResolveLoader"
     },
+    "snapshot": {
+      "$ref": "#/definitions/SnapshotOptions"
+    },
     "stats": {
       "$ref": "#/definitions/StatsValue"
     },

test/ConfigCacheTestCases.test.js

@@ -4,7 +4,9 @@ const { describeCases } = require("./ConfigTestCases.template");
 describeCases({
 	name: "ConfigCacheTestCases",
 	cache: {
-		type: "filesystem",
+		type: "filesystem"
+	},
+	snapshot: {
 		managedPaths: [path.resolve(__dirname, "../node_modules")]
 	}
 });

test/ConfigTestCases.template.js

@@ -72,6 +72,11 @@ const describeCases = config => {
 										...config.cache
 									};
 								}
+								if (config.snapshot) {
+									options.snapshot = {
+										...config.snapshot
+									};
+								}
 							});
 							testConfig = {
 								findBundle: function (i, options) {

test/Defaults.unittest.js

@@ -444,6 +444,26 @@ describe("Defaults", () => {
 		      "index",
 		    ],
 		  },
+		  "snapshot": Object {
+		    "buildDependencies": Object {
+		      "hash": true,
+		      "timestamp": true,
+		    },
+		    "immutablePaths": Array [],
+		    "managedPaths": Array [
+		      "<cwd>/node_modules",
+		    ],
+		    "module": Object {
+		      "timestamp": true,
+		    },
+		    "resolve": Object {
+		      "timestamp": true,
+		    },
+		    "resolveBuildDependencies": Object {
+		      "hash": true,
+		      "timestamp": true,
+		    },
+		  },
 		  "stats": Object {},
 		  "target": "web",
 		  "watch": false,
@@ -527,6 +547,10 @@ describe("Defaults", () => {
 		+     "maxAssetSize": 250000,
 		+     "maxEntrypointSize": 250000,
 		+   },
+		@@ ... @@
+		+       "hash": true,
+		@@ ... @@
+		+       "hash": true,
 	`)
 	);
 	test("production", { mode: "production" }, e =>
@@ -585,6 +609,10 @@ describe("Defaults", () => {
 		+     "maxAssetSize": 250000,
 		+     "maxEntrypointSize": 250000,
 		+   },
+		@@ ... @@
+		+       "hash": true,
+		@@ ... @@
+		+       "hash": true,
 	`)
 	);
 	test("development", { mode: "development" }, e =>
@@ -595,10 +623,6 @@ describe("Defaults", () => {
 		@@ ... @@
 		-   "cache": false,
 		+   "cache": Object {
-		+     "immutablePaths": Array [],
-		+     "managedPaths": Array [
-		+       "<cwd>/node_modules",
-		+     ],
 		+     "type": "memory",
 		+   },
 		@@ ... @@
@@ -1271,10 +1295,6 @@ describe("Defaults", () => {
 		@@ ... @@
 		-   "cache": false,
 		+   "cache": Object {
-		+     "immutablePaths": Array [],
-		+     "managedPaths": Array [
-		+       "<cwd>/node_modules",
-		+     ],
 		+     "type": "memory",
 		+   },
 		@@ ... @@
@@ -1306,10 +1326,6 @@ describe("Defaults", () => {
 		+     "hashAlgorithm": "md4",
 		+     "idleTimeout": 60000,
 		+     "idleTimeoutForInitialStore": 0,
-		+     "immutablePaths": Array [],
-		+     "managedPaths": Array [
-		+       "<cwd>/node_modules",
-		+     ],
 		+     "name": "default-none",
 		+     "store": "pack",
 		+     "type": "filesystem",

test/TestCasesCachePack.test.js

@@ -5,7 +5,9 @@ describe("TestCases", () => {
 	describeCases({
 		name: "cache pack",
 		cache: {
-			type: "filesystem",
+			type: "filesystem"
+		},
+		snapshot: {
 			managedPaths: [path.resolve(__dirname, "../node_modules")]
 		},
 		optimization: {

test/Validation.test.js

@@ -24,7 +24,7 @@ describe("Validation", () => {
 		expect(msg).toMatchInlineSnapshot(`
 		"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 		 - configuration should be an object:
-		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 		   -> Options object as provided by the user."
 	`)
 	);
@@ -33,7 +33,7 @@ describe("Validation", () => {
 		expect(msg).toMatchInlineSnapshot(`
 		"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 		 - configuration should be an object:
-		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+		   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 		   -> Options object as provided by the user."
 	`)
 	);
@@ -196,7 +196,7 @@ describe("Validation", () => {
 			expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration has an unknown property 'postcss'. These properties are valid:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user.
 			   For typos: please correct them.
 			   For loader options: webpack >= v2.0.0 no longer allows custom properties in configuration.
@@ -426,7 +426,7 @@ describe("Validation", () => {
 			expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration has an unknown property 'debug'. These properties are valid:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user.
 			   The 'debug' property was removed in webpack 2.0.0.
 			   Loaders should be updated to allow passing this option via loader options in module.rules.
@@ -482,7 +482,7 @@ describe("Validation", () => {
 			expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration[1] should be an object:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user."
 		`)
 	);
@@ -621,7 +621,7 @@ describe("Validation", () => {
 				expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration has an unknown property 'rules'. These properties are valid:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user.
 			   Did you mean module.rules?"
 		`)
@@ -635,7 +635,7 @@ describe("Validation", () => {
 				expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration has an unknown property 'splitChunks'. These properties are valid:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user.
 			   Did you mean optimization.splitChunks?"
 		`)
@@ -649,7 +649,7 @@ describe("Validation", () => {
 				expect(msg).toMatchInlineSnapshot(`
 			"Invalid configuration object. Webpack has been initialized using a configuration object that does not match the API schema.
 			 - configuration has an unknown property 'noParse'. These properties are valid:
-			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, stats?, target?, watch?, watchOptions? }
+			   object { amd?, bail?, cache?, context?, dependencies?, devServer?, devtool?, entry?, experiments?, externals?, externalsType?, infrastructureLogging?, loader?, mode?, module?, name?, node?, optimization?, output?, parallelism?, performance?, plugins?, profile?, recordsInputPath?, recordsOutputPath?, recordsPath?, resolve?, resolveLoader?, snapshot?, stats?, target?, watch?, watchOptions? }
 			   -> Options object as provided by the user.
 			   Did you mean module.noParse?"
 		`)

test/__snapshots__/Cli.test.js.snap

@@ -3552,6 +3552,162 @@ Object {
     "multiple": false,
     "simpleType": "boolean",
   },
+  "snapshot-build-dependencies-hash": Object {
+    "configs": Array [
+      Object {
+        "description": "Use hashes of the content of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.buildDependencies.hash",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use hashes of the content of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-build-dependencies-timestamp": Object {
+    "configs": Array [
+      Object {
+        "description": "Use timestamps of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.buildDependencies.timestamp",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use timestamps of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-immutable-paths": Object {
+    "configs": Array [
+      Object {
+        "description": "A path to a immutable directory (usually a package manager cache directory).",
+        "multiple": true,
+        "path": "snapshot.immutablePaths[]",
+        "type": "path",
+      },
+    ],
+    "description": "A path to a immutable directory (usually a package manager cache directory).",
+    "multiple": true,
+    "simpleType": "string",
+  },
+  "snapshot-immutable-paths-reset": Object {
+    "configs": Array [
+      Object {
+        "description": "Clear all items provided in configuration. List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.",
+        "multiple": false,
+        "path": "snapshot.immutablePaths",
+        "type": "reset",
+      },
+    ],
+    "description": "Clear all items provided in configuration. List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-managed-paths": Object {
+    "configs": Array [
+      Object {
+        "description": "A path to a managed directory (usually a node_modules directory).",
+        "multiple": true,
+        "path": "snapshot.managedPaths[]",
+        "type": "path",
+      },
+    ],
+    "description": "A path to a managed directory (usually a node_modules directory).",
+    "multiple": true,
+    "simpleType": "string",
+  },
+  "snapshot-managed-paths-reset": Object {
+    "configs": Array [
+      Object {
+        "description": "Clear all items provided in configuration. List of paths that are managed by a package manager and can be trusted to not be modified otherwise.",
+        "multiple": false,
+        "path": "snapshot.managedPaths",
+        "type": "reset",
+      },
+    ],
+    "description": "Clear all items provided in configuration. List of paths that are managed by a package manager and can be trusted to not be modified otherwise.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-module-hash": Object {
+    "configs": Array [
+      Object {
+        "description": "Use hashes of the content of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.module.hash",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use hashes of the content of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-module-timestamp": Object {
+    "configs": Array [
+      Object {
+        "description": "Use timestamps of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.module.timestamp",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use timestamps of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-resolve-build-dependencies-hash": Object {
+    "configs": Array [
+      Object {
+        "description": "Use hashes of the content of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.resolveBuildDependencies.hash",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use hashes of the content of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-resolve-build-dependencies-timestamp": Object {
+    "configs": Array [
+      Object {
+        "description": "Use timestamps of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.resolveBuildDependencies.timestamp",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use timestamps of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-resolve-hash": Object {
+    "configs": Array [
+      Object {
+        "description": "Use hashes of the content of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.resolve.hash",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use hashes of the content of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
+  "snapshot-resolve-timestamp": Object {
+    "configs": Array [
+      Object {
+        "description": "Use timestamps of the files/directories to determine invalidation.",
+        "multiple": false,
+        "path": "snapshot.resolve.timestamp",
+        "type": "boolean",
+      },
+    ],
+    "description": "Use timestamps of the files/directories to determine invalidation.",
+    "multiple": false,
+    "simpleType": "boolean",
+  },
   "stats": Object {
     "configs": Array [
       Object {

test/__snapshots__/StatsTestCases.test.js.snap

@@ -1164,9 +1164,9 @@ Entrypoint <CLR=BOLD>main</CLR> = <CLR=32,BOLD>main.js</CLR>
     <CLR=BOLD>0% root snapshot uncached (0 / 0)</CLR>
     <CLR=BOLD>0% children snapshot uncached (0 / 0)</CLR>
     <CLR=BOLD>0 entries tested</CLR>
-    <CLR=BOLD>File info in cache: 1 timestamps 0 hashes</CLR>
+    <CLR=BOLD>File info in cache: 1 timestamps 1 hashes 1 timestamp hash combinations</CLR>
-    <CLR=BOLD>File timestamp snapshot optimization: 0% (0/1) entries shared via 0 shared snapshots (0 times referenced)</CLR>
+    <CLR=BOLD>File timestamp hash combination snapshot optimization: 0% (0/1) entries shared via 0 shared snapshots (0 times referenced)</CLR>
-    <CLR=BOLD>Directory info in cache: 0 timestamps 0 hashes</CLR>
+    <CLR=BOLD>Directory info in cache: 0 timestamps 0 hashes 0 timestamp hash combinations</CLR>
     <CLR=BOLD>Managed items info in cache: 0 items</CLR>
 "
 `;
@@ -1973,9 +1973,9 @@ LOG from webpack.FileSystemInfo
     0% root snapshot uncached (0 / 0)
     0% children snapshot uncached (0 / 0)
     0 entries tested
-    File info in cache: 6 timestamps 0 hashes
+    File info in cache: 6 timestamps 6 hashes 6 timestamp hash combinations
-    File timestamp snapshot optimization: 0% (0/6) entries shared via 0 shared snapshots (0 times referenced)
+    File timestamp hash combination snapshot optimization: 0% (0/6) entries shared via 0 shared snapshots (0 times referenced)
-    Directory info in cache: 0 timestamps 0 hashes
+    Directory info in cache: 0 timestamps 0 hashes 0 timestamp hash combinations
     Managed items info in cache: 0 items
 "
 `;
@@ -2310,9 +2310,9 @@ LOG from webpack.FileSystemInfo
     0% root snapshot uncached (0 / 0)
     0% children snapshot uncached (0 / 0)
     0 entries tested
-    File info in cache: 6 timestamps 0 hashes
+    File info in cache: 6 timestamps 6 hashes 6 timestamp hash combinations
-    File timestamp snapshot optimization: 0% (0/6) entries shared via 0 shared snapshots (0 times referenced)
+    File timestamp hash combination snapshot optimization: 0% (0/6) entries shared via 0 shared snapshots (0 times referenced)
-    Directory info in cache: 0 timestamps 0 hashes
+    Directory info in cache: 0 timestamps 0 hashes 0 timestamp hash combinations
     Managed items info in cache: 0 items
 "
 `;

test/fixtures/buildDependencies/run.js

@@ -31,7 +31,9 @@ webpack(
 					__filename,
 					path.resolve(__dirname, "../../../node_modules/.yarn-integrity")
 				]
-			},
+			}
+		},
+		snapshot: {
 			managedPaths: [path.resolve(__dirname, "../../../node_modules")]
 		}
 	},

test/watchCases/cache/managedPath/webpack.config.js

@@ -4,7 +4,9 @@ const path = require("path");
 module.exports = {
 	mode: "development",
 	cache: {
-		type: "memory",
+		type: "memory"
+	},
+	snapshot: {
 		managedPaths: [
 			path.resolve(
 				__dirname,

test/watchCases/snapshot/unable-to-snapshot/webpack.config.js

@@ -2,7 +2,9 @@ const path = require("path");
 /** @type {function(any, any): import("../../../../").Configuration} */
 module.exports = (env, { srcPath }) => ({
 	cache: {
-		type: "memory",
+		type: "memory"
+	},
+	snapshot: {
 		managedPaths: [path.resolve(srcPath, "node_modules")]
 	}
 });

types.d.ts

@@ -1741,6 +1741,11 @@ declare interface Configuration {
 	 */
 	resolveLoader?: ResolveOptionsWebpackOptions;
 
+	/**
+	 * Options affecting how file system snapshots are created and validated.
+	 */
+	snapshot?: SnapshotOptions;
+
 	/**
 	 * Stats options object or preset name.
 	 */
@@ -3090,11 +3095,11 @@ declare abstract class FileSystemInfo {
 		missing: Iterable<string>,
 		options: {
 			/**
-			 * should use hash to snapshot
+			 * Use hashes of the content of the files/directories to determine invalidation.
 			 */
 			hash?: boolean;
 			/**
-			 * should use timestamp to snapshot
+			 * Use timestamps of the files/directories to determine invalidation.
 			 */
 			timestamp?: boolean;
 		},
@@ -4236,16 +4241,6 @@ declare interface MapOptions {
  * Options object for in-memory caching.
  */
 declare interface MemoryCacheOptions {
-	/**
-	 * List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.
-	 */
-	immutablePaths?: string[];
-
-	/**
-	 * List of paths that are managed by a package manager and can be trusted to not be modified otherwise.
-	 */
-	managedPaths?: string[];
-
 	/**
 	 * In memory caching.
 	 */
@@ -7859,8 +7854,10 @@ declare abstract class Snapshot {
 	startTime: number;
 	fileTimestamps: Map<string, FileSystemInfoEntry>;
 	fileHashes: Map<string, string>;
+	fileTshs: Map<string, string | TimestampAndHash>;
 	contextTimestamps: Map<string, FileSystemInfoEntry>;
 	contextHashes: Map<string, string>;
+	contextTshs: Map<string, string | TimestampAndHash>;
 	missingExistence: Map<string, boolean>;
 	managedItemInfo: Map<string, string>;
 	managedFiles: Set<string>;
@@ -7874,10 +7871,14 @@ declare abstract class Snapshot {
 	setFileTimestamps(value?: any): void;
 	hasFileHashes(): boolean;
 	setFileHashes(value?: any): void;
+	hasFileTshs(): boolean;
+	setFileTshs(value?: any): void;
 	hasContextTimestamps(): boolean;
 	setContextTimestamps(value?: any): void;
 	hasContextHashes(): boolean;
 	setContextHashes(value?: any): void;
+	hasContextTshs(): boolean;
+	setContextTshs(value?: any): void;
 	hasMissingExistence(): boolean;
 	setMissingExistence(value?: any): void;
 	hasManagedItemInfo(): boolean;
@@ -7897,6 +7898,77 @@ declare abstract class Snapshot {
 	getContextIterable(): Iterable<string>;
 	getMissingIterable(): Iterable<string>;
 }
+
+/**
+ * Options affecting how file system snapshots are created and validated.
+ */
+declare interface SnapshotOptions {
+	/**
+	 * Options for snapshotting build dependencies to determine if the whole cache need to be invalidated.
+	 */
+	buildDependencies?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+
+	/**
+	 * List of paths that are managed by a package manager and contain a version or hash in its path so all files are immutable.
+	 */
+	immutablePaths?: string[];
+
+	/**
+	 * List of paths that are managed by a package manager and can be trusted to not be modified otherwise.
+	 */
+	managedPaths?: string[];
+
+	/**
+	 * Options for snapshotting dependencies of modules to determine if they need to be built again.
+	 */
+	module?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+
+	/**
+	 * Options for snapshotting dependencies of request resolving to determine if requests need to be re-resolved.
+	 */
+	resolve?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+
+	/**
+	 * Options for snapshotting the resolving of build dependencies to determine if the build dependencies need to be re-resolved.
+	 */
+	resolveBuildDependencies?: {
+		/**
+		 * Use hashes of the content of the files/directories to determine invalidation.
+		 */
+		hash?: boolean;
+		/**
+		 * Use timestamps of the files/directories to determine invalidation.
+		 */
+		timestamp?: boolean;
+	};
+}
 declare abstract class SortableSet<T> extends Set<T> {
 	/**
 	 * Sort with a comparer function
@@ -8507,6 +8579,12 @@ declare class Template {
 	static NUMBER_OF_IDENTIFIER_START_CHARS: number;
 	static NUMBER_OF_IDENTIFIER_CONTINUATION_CHARS: number;
 }
+declare interface TimestampAndHash {
+	safeTime: number;
+	timestamp?: number;
+	timestampHash?: string;
+	hash: string;
+}
 declare const UNDEFINED_MARKER: unique symbol;
 declare interface UpdateHashContextDependency {
 	chunkGraph: ChunkGraph;
@@ -8970,6 +9048,11 @@ declare interface WebpackOptionsNormalized {
 	 */
 	resolveLoader: ResolveOptionsWebpackOptions;
 
+	/**
+	 * Options affecting how file system snapshots are created and validated.
+	 */
+	snapshot: SnapshotOptions;
+
 	/**
 	 * Stats options object or preset name.
 	 */