Make the tests happier

Here we just override the workers because we're not expecting to be able to test them this way. The code paths involved shouldn't be touched.

__mocks__/empty.js

@@ -0,0 +1,2 @@
+// Yes, this is empty.
+module.exports = {};

package.json

@@ -185,7 +185,10 @@
     ],
     "moduleNameMapper": {
       "\\.(gif|png|svg|ttf|woff2)$": "<rootDir>/__mocks__/imageMock.js",
-      "\\$webapp/i18n/languages.json": "<rootDir>/__mocks__/languages.json"
+      "\\$webapp/i18n/languages.json": "<rootDir>/__mocks__/languages.json",
+      "decoderWorker\\.min\\.js": "<rootDir>/__mocks__/empty.js",
+      "decoderWorker\\.min\\.wasm": "<rootDir>/__mocks__/empty.js",
+      "waveWorker\\.min\\.js": "<rootDir>/__mocks__/empty.js"
     },
     "transformIgnorePatterns": [
       "/node_modules/(?!matrix-js-sdk).+$"

src/voice/compat.ts

@@ -14,11 +14,12 @@ See the License for the specific language governing permissions and
 limitations under the License.
 */
 
-import wavEncoderPath from 'opus-recorder/dist/waveWorker.min.js';
-import decoderPath from 'opus-recorder/dist/decoderWorker.min.js';
 import {SAMPLE_RATE} from "./VoiceRecording";
+
 // @ts-ignore - we know that this is not a module. We're looking for a path.
 import decoderWasmPath from 'opus-recorder/dist/decoderWorker.min.wasm';
+import wavEncoderPath from 'opus-recorder/dist/waveWorker.min.js';
+import decoderPath from 'opus-recorder/dist/decoderWorker.min.js';
 
 export function createAudioContext(opts?: AudioContextOptions): AudioContext {
     if (window.AudioContext) {