fix: source maps to work correctly

package.json

@@ -41,9 +41,10 @@
 		"webpack": "4 || 5"
 	},
 	"dependencies": {
+		"@cspotcode/source-map-support": "^0.8.1",
 		"fs-require": "^1.6.0",
 		"memfs": "^3.5.0",
-		"source-map-support": "^0.5.21",
+		"source-map-url": "^0.4.1",
 		"yargs": "^16.2.0"
 	},
 	"devDependencies": {

src/lib/memfs.ts

@@ -1,20 +1,57 @@
 import path from 'path';
 import { createFsFromVolume, Volume } from 'memfs';
 import { createFsRequire } from 'fs-require';
-import sourceMapSupport from 'source-map-support';
+import sourceMapSupport from '@cspotcode/source-map-support';
+import sourceMappingURL from 'source-map-url';
 
 export const mfs = createFsFromVolume(new Volume());
 
 // @ts-expect-error To support Webpack 4. No longer needed in WP5
 mfs.join = path.join;
 
+function removeFsRequirePrefix(filePath: string) {
+	const fsRequirePrefix = 'fs-require://1';
+
+	if (filePath.startsWith(fsRequirePrefix)) {
+		return filePath.slice(fsRequirePrefix.length);
+	}
+
+	return filePath;
+}
+
 sourceMapSupport.install({
 	environment: 'node',
 	retrieveFile(filePath: string) {
-		if (mfs.existsSync(filePath)) {
-			return mfs.readFileSync(filePath).toString();
+		const filteredFilePath = removeFsRequirePrefix(filePath);
+
+		if (mfs.existsSync(filteredFilePath)) {
+			return mfs.readFileSync(filteredFilePath).toString();
 		}
 	},
+	retrieveSourceMap(sourceFilePath: string) {
+		const filteredSourceFilePath = removeFsRequirePrefix(sourceFilePath);
+
+		if (mfs.existsSync(filteredSourceFilePath)) {
+			const sourceFileContent = mfs.readFileSync(filteredSourceFilePath).toString();
+			const sourceMapFilePath = sourceMappingURL.getFrom(sourceFileContent);
+
+			if (sourceMapFilePath === null) {
+				return null;
+			}
+
+			const parentDirectory = path.dirname(filteredSourceFilePath);
+			const sourceMapFileFullPath = `${parentDirectory}/${sourceMapFilePath}`;
+
+			if (mfs.existsSync(sourceMapFileFullPath)) {
+				return {
+					url: sourceFilePath,
+					map: mfs.readFileSync(sourceMapFileFullPath).toString(),
+				};
+			}
+		}
+
+		return null;
+	},
 });
 
 export const mRequire = (modulePath: string): any => (