Add custom loader for recorder worklet

recorder-worklet-loader.js

@@ -0,0 +1,45 @@
+/*
+Copyright 2023 The Matrix.org Foundation C.I.C.
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+// Inspired by https://github.com/reklawnos/worklet-loader which doesn't
+// formally support Webpack 5
+
+const SingleEntryPlugin = require("webpack/lib/SingleEntryPlugin");
+
+module.exports = function () {};
+
+module.exports.pitch = function pitch(request) {
+    const cb = this.async();
+    const filename = "recorder.worklet.js";
+
+    const compiler = this._compilation.createChildCompiler("worker", {
+        filename,
+        chunkFilename: `[id].${filename}`,
+        namedChunkFilename: null,
+    });
+
+    new SingleEntryPlugin(this.context, `!!${request}`, "main").apply(compiler);
+
+    compiler.runAsChild((err, entries, compilation) => {
+        if (err) {
+            return cb(err);
+        }
+        if (entries[0]) {
+            return cb(null, `module.exports = __webpack_public_path__ + ${JSON.stringify(entries[0].files[0])};`);
+        }
+        return cb(null, null);
+    });
+};