refactor: CSS HMR

lib/CssModule.js

@@ -65,6 +65,11 @@ class CssModule extends NormalModule {
 			identifier += `|${inheritance.join("|")}`;
 		}
 
+		// We generate extra code for HMR, so we need to invalidate the module
+		if (this.hot) {
+			identifier += `|${this.hot}`;
+		}
+
 		return identifier;
 	}
 

lib/DependencyTemplate.js

@@ -40,11 +40,11 @@
 
 /**
  * @typedef {object} CssDependencyTemplateContextExtras
- * @property {CssExportsData} cssExportsData the css exports data
+ * @property {CssData} cssData the css exports data
  */
 
 /**
- * @typedef {object} CssExportsData
+ * @typedef {object} CssData
  * @property {boolean} esModule whether export __esModule
  * @property {Map<string, string>} exports the css exports
  */

lib/HotModuleReplacementPlugin.js

@@ -856,6 +856,10 @@ To fix this, make sure to include [runtime] in the output.hotUpdateMainFilename
 					.tap(PLUGIN_NAME, parser => {
 						applyImportMetaHot(parser);
 					});
+				normalModuleFactory.hooks.module.tap(PLUGIN_NAME, module => {
+					module.hot = true;
+					return module;
+				});
 
 				NormalModule.getCompilationHooks(compilation).loader.tap(
 					PLUGIN_NAME,

lib/Module.js

@@ -200,6 +200,9 @@ class Module extends DependenciesBlock {
 		/** @type {boolean} */
 		this.useSimpleSourceMap = false;
 
+		// Is hot context
+		/** @type {boolean} */
+		this.hot = false;
 		// Info from Build
 		/** @type {WebpackError[] | undefined} */
 		this._warnings = undefined;
@@ -1075,6 +1078,7 @@ class Module extends DependenciesBlock {
 		write(this.factoryMeta);
 		write(this.useSourceMap);
 		write(this.useSimpleSourceMap);
+		write(this.hot);
 		write(
 			this._warnings !== undefined && this._warnings.length === 0
 				? undefined
@@ -1104,6 +1108,7 @@ class Module extends DependenciesBlock {
 		this.factoryMeta = read();
 		this.useSourceMap = read();
 		this.useSimpleSourceMap = read();
+		this.hot = read();
 		this._warnings = read();
 		this._errors = read();
 		this.buildMeta = read();

lib/css/CssGenerator.js

@@ -22,8 +22,8 @@ const Template = require("../Template");
 /** @typedef {import("../../declarations/WebpackOptions").CssModuleGeneratorOptions} CssModuleGeneratorOptions */
 /** @typedef {import("../CodeGenerationResults")} CodeGenerationResults */
 /** @typedef {import("../Dependency")} Dependency */
+/** @typedef {import("../DependencyTemplate").CssData} CssData */
 /** @typedef {import("../DependencyTemplate").CssDependencyTemplateContext} DependencyTemplateContext */
-/** @typedef {import("../DependencyTemplate").CssExportsData} CssExportsData */
 /** @typedef {import("../Generator").GenerateContext} GenerateContext */
 /** @typedef {import("../Generator").UpdateHashContext} UpdateHashContext */
 /** @typedef {import("../Module").ConcatenationBailoutReasonContext} ConcatenationBailoutReasonContext */
@@ -69,8 +69,8 @@ class CssGenerator extends Generator {
 
 		/** @type {InitFragment<GenerateContext>[]} */
 		const initFragments = [];
-		/** @type {CssExportsData} */
-		const cssExportsData = {
+		/** @type {CssData} */
+		const cssData = {
 			esModule: this.esModule,
 			exports: new Map()
 		};
@@ -91,7 +91,7 @@ class CssGenerator extends Generator {
 				/** @type {CodeGenerationResults} */
 				(generateContext.codeGenerationResults),
 			initFragments,
-			cssExportsData,
+			cssData,
 			get chunkInitFragments() {
 				if (!chunkInitFragments) {
 					const data =
@@ -131,12 +131,14 @@ class CssGenerator extends Generator {
 
 		switch (generateContext.type) {
 			case "javascript": {
+				module.buildInfo.cssData = cssData;
+
 				generateContext.runtimeRequirements.add(RuntimeGlobals.module);
 
 				if (generateContext.concatenationScope) {
 					const source = new ConcatSource();
 					const usedIdentifiers = new Set();
-					for (const [name, v] of cssExportsData.exports) {
+					for (const [name, v] of cssData.exports) {
 						const usedName = generateContext.moduleGraph
 							.getExportInfo(module, name)
 							.getUsedName(name, generateContext.runtime);
@@ -180,7 +182,7 @@ class CssGenerator extends Generator {
 
 				const exports = [];
 
-				for (const [name, v] of cssExportsData.exports) {
+				for (const [name, v] of cssData.exports) {
 					exports.push(`\t${JSON.stringify(name)}: ${JSON.stringify(v)}`);
 				}
 
@@ -199,11 +201,6 @@ class CssGenerator extends Generator {
 
 				generateContext.runtimeRequirements.add(RuntimeGlobals.hasCssModules);
 
-				const data =
-					/** @type {NonNullable<GenerateContext["getData"]>} */
-					(generateContext.getData)();
-				data.set("css-exports", cssExportsData);
-
 				return InitFragment.addToSource(source, initFragments, generateContext);
 			}
 		}
@@ -226,7 +223,16 @@ class CssGenerator extends Generator {
 	getSize(module, type) {
 		switch (type) {
 			case "javascript": {
-				return 42;
+				/** @type {undefined} */
+				const exports = module.buildInfo.cssData.exports;
+				const stringifiedExports = JSON.stringify(
+					Array.from(exports).reduce((obj, [key, value]) => {
+						obj[key] = value;
+						return obj;
+					}, {})
+				);
+
+				return stringifiedExports.length + 42;
 			}
 			case "css": {
 				const originalSource = module.originalSource();

lib/css/CssLoadingRuntimeModule.js

@@ -190,21 +190,13 @@ class CssLoadingRuntimeModule extends RuntimeModule {
 						runtimeTemplate.outputOptions.uniqueName
 					)};`
 				: "// data-webpack is not used as build has no uniqueName",
-			`var loadCssChunkData = ${runtimeTemplate.basicFunction(
-				"target, chunkId",
-				[
-					`${withHmr ? "var moduleIds = [];" : ""}`,
-					`${
-						withHmr ? `if(target == ${RuntimeGlobals.moduleFactories}) ` : ""
-					}installedChunks[chunkId] = 0;`,
-					withHmr ? "return moduleIds;" : ""
-				]
-			)}`,
+			withLoading || withHmr
+				? Template.asString([
 						'var loadingAttribute = "data-webpack-loading";',
 						`var loadStylesheet = ${runtimeTemplate.basicFunction(
-				`chunkId, url, done${withHmr ? ", hmr" : ""}${
+							`chunkId, url, done${
 								withFetchPriority ? ", fetchPriority" : ""
-				}`,
+							}${withHmr ? ", hmr" : ""}`,
 							[
 								'var link, needAttach, key = "chunk-" + chunkId;',
 								withHmr ? "if(!hmr) {" : "",
@@ -249,12 +241,16 @@ class CssLoadingRuntimeModule extends RuntimeModule {
 									"link.onload = onLinkComplete.bind(null, link.onload);"
 								]),
 								"} else onLinkComplete(undefined, { type: 'load', target: link });", // We assume any existing stylesheet is render blocking
+								withFetchPriority
+									? 'if (hmr && hmr.getAttribute("fetchpriority")) link.setAttribute("fetchpriority", hmr.getAttribute("fetchpriority"));'
+									: "",
 								withHmr ? "hmr ? document.head.insertBefore(link, hmr) :" : "",
 								"needAttach && document.head.appendChild(link);",
 								"return link;"
 							]
-			)};`,
-			"",
+						)};`
+					])
+				: "",
 			withLoading
 				? Template.asString([
 						`${fn}.css = ${runtimeTemplate.basicFunction(
@@ -306,7 +302,7 @@ class CssLoadingRuntimeModule extends RuntimeModule {
 															]),
 															"} else {",
 															Template.indent([
-																`loadCssChunkData(${RuntimeGlobals.moduleFactories}, chunkId);`,
+																"installedChunks[chunkId] = 0;",
 																"installedChunkData[0]();"
 															]),
 															"}"
@@ -429,32 +425,20 @@ class CssLoadingRuntimeModule extends RuntimeModule {
 						"var oldTags = [];",
 						"var newTags = [];",
 						`var applyHandler = ${runtimeTemplate.basicFunction("options", [
-							`return { dispose: ${runtimeTemplate.basicFunction(
-								"",
-								[]
-							)}, apply: ${runtimeTemplate.basicFunction("", [
-								"var moduleIds = [];",
-								`newTags.forEach(${runtimeTemplate.expressionFunction(
-									"info[1].sheet.disabled = false",
-									"info"
-								)});`,
+							`return { dispose: ${runtimeTemplate.basicFunction("", [
 								"while(oldTags.length) {",
 								Template.indent([
 									"var oldTag = oldTags.pop();",
 									"if(oldTag.parentNode) oldTag.parentNode.removeChild(oldTag);"
 								]),
-								"}",
+								"}"
+							])}, apply: ${runtimeTemplate.basicFunction("", [
 								"while(newTags.length) {",
 								Template.indent([
-									"var info = newTags.pop();",
-									`var chunkModuleIds = loadCssChunkData(${RuntimeGlobals.moduleFactories}, info[0]);`,
-									`chunkModuleIds.forEach(${runtimeTemplate.expressionFunction(
-										"moduleIds.push(id)",
-										"id"
-									)});`
+									"var newTag = newTags.pop();",
+									"newTag.sheet.disabled = false"
 								]),
-								"}",
-								"return moduleIds;"
+								"}"
 							])} };`
 						])}`,
 						`var cssTextKey = ${runtimeTemplate.returningFunction(
@@ -494,20 +478,14 @@ class CssLoadingRuntimeModule extends RuntimeModule {
 													"} else {",
 													Template.indent([
 														"try { if(cssTextKey(oldTag) == cssTextKey(link)) { if(link.parentNode) link.parentNode.removeChild(link); return resolve(); } } catch(e) {}",
-														"var factories = {};",
-														"loadCssChunkData(factories, chunkId);",
-														`Object.keys(factories).forEach(${runtimeTemplate.expressionFunction(
-															"updatedModulesList.push(id)",
-															"id"
-														)})`,
 														"link.sheet.disabled = true;",
 														"oldTags.push(oldTag);",
-														"newTags.push([chunkId, link]);",
+														"newTags.push(link);",
 														"resolve();"
 													]),
 													"}"
 												]
-											)}, oldTag);`
+											)}, ${withFetchPriority ? "undefined," : ""} oldTag);`
 										]
 									)}));`
 								])});`

lib/css/CssModulesPlugin.js

@@ -10,7 +10,8 @@ const {
 	ConcatSource,
 	PrefixSource,
 	ReplaceSource,
-	CachedSource
+	CachedSource,
+	RawSource
 } = require("webpack-sources");
 const Compilation = require("../Compilation");
 const CssModule = require("../CssModule");
@@ -24,6 +25,7 @@ const {
 } = require("../ModuleTypeConstants");
 const RuntimeGlobals = require("../RuntimeGlobals");
 const SelfModuleFactory = require("../SelfModuleFactory");
+const Template = require("../Template");
 const WebpackError = require("../WebpackError");
 const CssIcssExportDependency = require("../dependencies/CssIcssExportDependency");
 const CssIcssImportDependency = require("../dependencies/CssIcssImportDependency");
@@ -33,6 +35,7 @@ const CssLocalIdentifierDependency = require("../dependencies/CssLocalIdentifier
 const CssSelfLocalIdentifierDependency = require("../dependencies/CssSelfLocalIdentifierDependency");
 const CssUrlDependency = require("../dependencies/CssUrlDependency");
 const StaticExportsDependency = require("../dependencies/StaticExportsDependency");
+const JavascriptModulesPlugin = require("../javascript/JavascriptModulesPlugin");
 const { compareModulesByIdentifier } = require("../util/comparators");
 const createSchemaValidation = require("../util/create-schema-validation");
 const createHash = require("../util/createHash");
@@ -358,8 +361,36 @@ class CssModulesPlugin {
 							return new CssModule(createData);
 						});
 				}
+
+				JavascriptModulesPlugin.getCompilationHooks(
+					compilation
+				).renderModuleContent.tap(PLUGIN_NAME, (source, module) => {
+					if (module instanceof CssModule && module.hot) {
+						const exports = module.buildInfo.cssData.exports;
+						const stringifiedExports = JSON.stringify(
+							Array.from(exports).reduce((obj, [key, value]) => {
+								obj[key] = value;
+								return obj;
+							}, {})
+						);
+
+						const hmrCode = Template.asString([
+							"",
+							`var exports = ${stringifiedExports};`,
+							"// only invalidate when locals change",
+							"if (module.hot.data && module.hot.data.exports && module.hot.data.exports != exports) {",
+							Template.indent("module.hot.invalidate();"),
+							"} else {",
+							Template.indent("module.hot.accept();"),
+							"}",
+							"module.hot.dispose(function(data) { data.exports = exports; });"
+						]);
+
+						return new ConcatSource(source, "\n", new RawSource(hmrCode));
+					}
+				});
 				const orderedCssModulesPerChunk = new WeakMap();
-				compilation.hooks.afterCodeGeneration.tap("CssModulesPlugin", () => {
+				compilation.hooks.afterCodeGeneration.tap(PLUGIN_NAME, () => {
 					const { chunkGraph } = compilation;
 					for (const chunk of compilation.chunks) {
 						if (CssModulesPlugin.chunkHasCss(chunk, chunkGraph)) {
@@ -370,13 +401,10 @@ class CssModulesPlugin {
 						}
 					}
 				});
-				compilation.hooks.chunkHash.tap(
-					"CssModulesPlugin",
-					(chunk, hash, context) => {
+				compilation.hooks.chunkHash.tap(PLUGIN_NAME, (chunk, hash, context) => {
 					hooks.chunkHash.call(chunk, hash, context);
-					}
-				);
-				compilation.hooks.contentHash.tap("CssModulesPlugin", chunk => {
+				});
+				compilation.hooks.contentHash.tap(PLUGIN_NAME, chunk => {
 					const {
 						chunkGraph,
 						codeGenerationResults,
@@ -483,7 +511,6 @@ class CssModulesPlugin {
 					onceForChunkSet.add(chunk);
 					if (!isEnabledForChunk(chunk)) return;
 
-					set.add(RuntimeGlobals.moduleFactoriesAddOnly);
 					set.add(RuntimeGlobals.makeNamespaceObject);
 
 					const CssLoadingRuntimeModule = getCssLoadingRuntimeModule();
@@ -531,7 +558,6 @@ class CssModulesPlugin {
 						}
 						set.add(RuntimeGlobals.publicPath);
 						set.add(RuntimeGlobals.getChunkCssFilename);
-						set.add(RuntimeGlobals.moduleFactoriesAddOnly);
 					});
 			}
 		);
@@ -801,7 +827,6 @@ class CssModulesPlugin {
 	 */
 	renderChunk(
 		{
-			uniqueName,
 			undoPath,
 			chunk,
 			chunkGraph,

lib/dependencies/CssIcssExportDependency.js

@@ -125,11 +125,7 @@ CssIcssExportDependency.Template = class CssIcssExportDependencyTemplate extends
 	 * @param {DependencyTemplateContext} templateContext the context object
 	 * @returns {void}
 	 */
-	apply(
-		dependency,
-		source,
-		{ cssExportsData, module: m, runtime, moduleGraph }
-	) {
+	apply(dependency, source, { cssData, module: m, runtime, moduleGraph }) {
 		const dep = /** @type {CssIcssExportDependency} */ (dependency);
 		const module = /** @type {CssModule} */ (m);
 		const convention =
@@ -147,7 +143,7 @@ CssIcssExportDependency.Template = class CssIcssExportDependencyTemplate extends
 			);
 
 		for (const used of usedNames.concat(names)) {
-			cssExportsData.exports.set(used, dep.value);
+			cssData.exports.set(used, dep.value);
 		}
 	}
 };

lib/dependencies/CssIcssSymbolDependency.js

@@ -115,12 +115,12 @@ CssIcssSymbolDependency.Template = class CssValueAtRuleDependencyTemplate extend
 	 * @param {DependencyTemplateContext} templateContext the context object
 	 * @returns {void}
 	 */
-	apply(dependency, source, { cssExportsData }) {
+	apply(dependency, source, { cssData }) {
 		const dep = /** @type {CssIcssSymbolDependency} */ (dependency);
 
 		source.replace(dep.range[0], dep.range[1] - 1, dep.value);
 
-		cssExportsData.exports.set(dep.name, dep.value);
+		cssData.exports.set(dep.name, dep.value);
 	}
 };
 

lib/dependencies/CssLocalIdentifierDependency.js

@@ -338,7 +338,7 @@ CssLocalIdentifierDependency.Template = class CssLocalIdentifierDependencyTempla
 	 * @returns {void}
 	 */
 	apply(dependency, source, templateContext) {
-		const { module: m, moduleGraph, runtime, cssExportsData } = templateContext;
+		const { module: m, moduleGraph, runtime, cssData } = templateContext;
 		const dep = /** @type {CssLocalIdentifierDependency} */ (dependency);
 		const module = /** @type {CssModule} */ (m);
 		const convention =
@@ -364,7 +364,7 @@ CssLocalIdentifierDependency.Template = class CssLocalIdentifierDependencyTempla
 		source.replace(dep.range[0], dep.range[1] - 1, identifier);
 
 		for (const used of usedNames.concat(names)) {
-			cssExportsData.exports.set(used, identifier);
+			cssData.exports.set(used, identifier);
 		}
 	}
 };

types.d.ts

@@ -8730,6 +8730,7 @@ declare class Module extends DependenciesBlock {
 	factoryMeta?: FactoryMeta;
 	useSourceMap: boolean;
 	useSimpleSourceMap: boolean;
+	hot: boolean;
 	buildMeta?: BuildMeta;
 	buildInfo?: BuildInfo;
 	presentationalDependencies?: Dependency[];