Fixes worker sandbox problems (#4975)

build/amd/plugin.js

@@ -0,0 +1,60 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+/**
+ * @type {() => import('rollup').Plugin}
+ */
+export function urlToEsmPlugin() {
+	return {
+		name: 'import-meta-url',
+		async transform(code, id) {
+			if (this.environment?.mode === 'dev') {
+				return;
+			}
+			let idx = 0;
+
+			// Look for `new URL("...?worker", import.meta.url)` patterns.
+			const regex = /new\s+URL\s*\(\s*(['"`])(.*?)\?worker\1\s*,\s*import\.meta\.url\s*\)?/g;
+
+			let match;
+			let modified = false;
+			let result = code;
+			let offset = 0;
+			/** @type {string[]} */
+			const additionalImports = [];
+
+			while ((match = regex.exec(code)) !== null) {
+				let path = match[2];
+
+				if (!path.startsWith('.') && !path.startsWith('/')) {
+					path = `./${path}`;
+				}
+
+				const start = match.index;
+				const end = start + match[0].length;
+
+				const varName = `__worker_url_${idx++}__`;
+				additionalImports.push(`import ${varName} from ${JSON.stringify(path + '?worker&url')};`);
+
+				const replacement = varName;
+
+				result = result.slice(0, start + offset) + replacement + result.slice(end + offset);
+				offset += replacement.length - (end - start);
+				modified = true;
+			}
+
+			if (!modified) {
+				return null;
+			}
+
+			result = additionalImports.join('\n') + '\n' + result;
+
+			return {
+				code: result,
+				map: null
+			};
+		}
+	};
+}