add emit option for asset modules

fixes webpack#12474
AnatidaeProject · Mar 11, 2021 · 7572217 · 7572217
1 parent 85a6eee
commit 7572217
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Showing 7 changed files with 55 additions and 3 deletions.
diff --git a/declarations/WebpackOptions.d.ts b/declarations/WebpackOptions.d.ts
@@ -2584,6 +2584,10 @@ export interface AssetParserOptions {
  * Generator options for asset/resource modules.
  */
 export interface AssetResourceGeneratorOptions {
+	/**
+	 * Emit an output asset from this asset module. This can be set to 'false' to omit emitting e. g. for SSR.
+	 */
+	emit?: boolean;
 	/**
 	 * Specifies the filename template of output files on disk. You must **not** specify an absolute path here, but the path may contain folders separated by '/'! The specified path is joined with the value of the 'output.path' option to determine the location on disk.
 	 */

diff --git a/lib/asset/AssetGenerator.js b/lib/asset/AssetGenerator.js
@@ -31,11 +31,13 @@ class AssetGenerator extends Generator {
 	/**
 	 * @param {AssetGeneratorOptions["dataUrl"]=} dataUrlOptions the options for the data url
 	 * @param {string=} filename override for output.assetModuleFilename
+	 * @param {boolean=} emit generate output asset
 	 */
-	constructor(dataUrlOptions, filename) {
+	constructor(dataUrlOptions, filename, emit) {
 		super();
 		this.dataUrlOptions = dataUrlOptions;
 		this.filename = filename;
+		this.emit = emit;
 	}
 
 	/**
@@ -174,7 +176,7 @@ class AssetGenerator extends Generator {
 	 * @returns {Set<string>} available types (do not mutate)
 	 */
 	getTypes(module) {
-		if (module.buildInfo.dataUrl) {
+		if (module.buildInfo.dataUrl || this.emit === false) {
 			return JS_TYPES;
 		} else {
 			return JS_AND_ASSET_TYPES;

diff --git a/lib/asset/AssetModulesPlugin.js b/lib/asset/AssetModulesPlugin.js
@@ -124,7 +124,11 @@ class AssetModulesPlugin {
 
 							const AssetGenerator = getAssetGenerator();
 
-							return new AssetGenerator(dataUrl, filename);
+							return new AssetGenerator(
+								dataUrl,
+								filename,
+								generatorOptions.emit !== false
+							);
 						});
 				}
 				normalModuleFactory.hooks.createGenerator

diff --git a/schemas/WebpackOptions.json b/schemas/WebpackOptions.json
@@ -101,6 +101,10 @@
         "dataUrl": {
           "$ref": "#/definitions/AssetGeneratorDataUrl"
         },
+        "emit": {
+          "description": "Emit an output asset from this asset module. This can be set to 'false' to omit emitting e. g. for SSR.",
+          "type": "boolean"
+        },
         "filename": {
           "$ref": "#/definitions/FilenameTemplate"
         }
@@ -168,6 +172,10 @@
       "type": "object",
       "additionalProperties": false,
       "properties": {
+        "emit": {
+          "description": "Emit an output asset from this asset module. This can be set to 'false' to omit emitting e. g. for SSR.",
+          "type": "boolean"
+        },
         "filename": {
           "$ref": "#/definitions/FilenameTemplate"
         }

diff --git a/test/configCases/asset-modules/emit/index.js b/test/configCases/asset-modules/emit/index.js
@@ -0,0 +1,11 @@
+import url from "../_images/file.png";
+import fs from "fs";
+
+it("should output asset with path", () => {
+	expect(url).toEqual("images/file.png");
+	expect(() => fs.statSync(url)).toThrowError(
+		expect.objectContaining({
+			code: "ENOENT"
+		})
+	);
+});
diff --git a/test/configCases/asset-modules/emit/webpack.config.js b/test/configCases/asset-modules/emit/webpack.config.js
@@ -0,0 +1,18 @@
+/** @type {import("../../../../").Configuration} */
+module.exports = {
+	mode: "development",
+	output: {
+		assetModuleFilename: "images/file[ext]"
+	},
+	module: {
+		rules: [
+			{
+				test: /\.png$/,
+				type: "asset",
+				generator: {
+					emit: false
+				}
+			}
+		]
+	}
+};
diff --git a/types.d.ts b/types.d.ts
@@ -299,6 +299,11 @@ declare interface AssetParserOptions {
  * Generator options for asset/resource modules.
  */
 declare interface AssetResourceGeneratorOptions {
+	/**
+	 * Emit an output asset from this asset module. This can be set to 'false' to omit emitting e. g. for SSR.
+	 */
+	emit?: boolean;
+
 	/**
 	 * Specifies the filename template of output files on disk. You must **not** specify an absolute path here, but the path may contain folders separated by '/'! The specified path is joined with the value of the 'output.path' option to determine the location on disk.
 	 */