refactor: extract asset type determination logic into util module

lib/dependencies/URLDependency.js

@@ -10,6 +10,7 @@ const RawDataUrlModule = require("../asset/RawDataUrlModule");
 const {
 	getDependencyUsedByExportsCondition
 } = require("../optimize/InnerGraph");
+const getAssetType = require("../util/assetType");
 const makeSerializable = require("../util/makeSerializable");
 const memoize = require("../util/memoize");
 const ModuleDependency = require("./ModuleDependency");
@@ -34,34 +35,6 @@ const getIgnoredRawDataUrlModule = memoize(
 	() => new RawDataUrlModule("data:,", "ignored-asset", "(ignored asset)")
 );
 
-/**
- * Determines the 'as' attribute value for prefetch/preload based on file extension
- * @param {string} request The module request string
- * @returns {string} The 'as' attribute value
- */
-const getAssetType = (request) => {
-	// Reference: MDN rel=preload documentation (https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/rel/preload#what_types_of_content_can_be_preloaded)
-	// Valid 'as' values: fetch, font, image, script, style, track
-	if (/\.(png|jpe?g|gif|svg|webp|avif|bmp|ico|tiff?)$/i.test(request)) {
-		return "image";
-	} else if (/\.(woff2?|ttf|otf|eot)$/i.test(request)) {
-		return "font";
-	} else if (/\.(js|mjs|jsx|ts|tsx)$/i.test(request)) {
-		return "script";
-	} else if (/\.css$/i.test(request)) {
-		return "style";
-	} else if (/\.vtt$/i.test(request)) {
-		return "track"; // WebVTT files for video subtitles/captions
-	} else if (
-		/\.(mp4|webm|ogg|mp3|wav|flac|aac|m4a|avi|mov|wmv|mkv)$/i.test(request)
-	) {
-		// Audio/video files: use 'fetch' as fallback since as='audio'/'video' not supported
-		// Reference: https://github.com/mdn/browser-compat-data/issues/9577
-		return "fetch";
-	}
-	return "fetch"; // Generic fetch for unknown types
-};
-
 class URLDependency extends ModuleDependency {
 	/**
 	 * @param {string} request request

lib/prefetch/AssetPrefetchStartupPlugin.js

@@ -6,6 +6,7 @@
 "use strict";
 
 const RuntimeGlobals = require("../RuntimeGlobals");
+const getAssetType = require("../util/assetType");
 const AssetPrefetchStartupRuntimeModule = require("./AssetPrefetchStartupRuntimeModule");
 
 /** @typedef {import("../Chunk")} Chunk */
@@ -105,8 +106,7 @@ class AssetPrefetchStartupPlugin {
 									assetUrl = request.split(/[\\/]/).pop() || request;
 								}
 
-								const assetType =
+								const assetType = getAssetType(request);
-									AssetPrefetchStartupPlugin._getAssetType(request);
 								const info = {
 									url: assetUrl,
 									as: assetType,
@@ -176,30 +176,6 @@ class AssetPrefetchStartupPlugin {
 				});
 		});
 	}
-
-	/**
-	 * Determines the 'as' attribute value for prefetch/preload based on file extension
-	 * @param {string} request The module request string
-	 * @returns {string} The 'as' attribute value
-	 */
-	static _getAssetType(request) {
-		if (/\.(png|jpe?g|gif|svg|webp|avif|bmp|ico|tiff?)$/i.test(request)) {
-			return "image";
-		} else if (/\.(woff2?|ttf|otf|eot)$/i.test(request)) {
-			return "font";
-		} else if (/\.(js|mjs|jsx|ts|tsx)$/i.test(request)) {
-			return "script";
-		} else if (/\.css$/i.test(request)) {
-			return "style";
-		} else if (/\.vtt$/i.test(request)) {
-			return "track";
-		} else if (
-			/\.(mp4|webm|ogg|mp3|wav|flac|aac|m4a|avi|mov|wmv|mkv)$/i.test(request)
-		) {
-			return "fetch";
-		}
-		return "fetch";
-	}
 }
 
 module.exports = AssetPrefetchStartupPlugin;

lib/util/assetType.js

@@ -0,0 +1,36 @@
+/*
+	MIT License http://www.opensource.org/licenses/mit-license.php
+	Author Tobias Koppers @sokra
+*/
+
+"use strict";
+
+/**
+ * Determines the 'as' attribute value for prefetch/preload based on file extension
+ * Reference: MDN rel=preload documentation
+ * https://developer.mozilla.org/en-US/docs/Web/HTML/Reference/Attributes/rel/preload#what_types_of_content_can_be_preloaded
+ * @param {string} request The module request string or filename
+ * @returns {string} The 'as' attribute value for link element
+ */
+const getAssetType = (request) => {
+	if (/\.(png|jpe?g|gif|svg|webp|avif|bmp|ico|tiff?)$/i.test(request)) {
+		return "image";
+	} else if (/\.(woff2?|ttf|otf|eot)$/i.test(request)) {
+		return "font";
+	} else if (/\.(js|mjs|jsx|ts|tsx)$/i.test(request)) {
+		return "script";
+	} else if (/\.css$/i.test(request)) {
+		return "style";
+	} else if (/\.vtt$/i.test(request)) {
+		return "track";
+	} else if (
+		/\.(mp4|webm|ogg|mp3|wav|flac|aac|m4a|avi|mov|wmv|mkv)$/i.test(request)
+	) {
+		// Audio/video files: use 'fetch' as fallback since as='audio'/'video' not supported
+		// Reference: https://github.com/mdn/browser-compat-data/issues/9577
+		return "fetch";
+	}
+	return "fetch";
+};
+
+module.exports = getAssetType;