async start()

in src/frontends/live_api_react/frontend/src/utils/audio-recorder.ts [48:93]
37 lines of code
4 McCabe index (conditional complexity)

  async start() {
    if (!navigator.mediaDevices || !navigator.mediaDevices.getUserMedia) {
      throw new Error("Could not request user media");
    }

    this.starting = new Promise(async (resolve, reject) => {
      this.stream = await navigator.mediaDevices.getUserMedia({ audio: true });
      this.audioContext = await audioContext({ sampleRate: this.sampleRate });
      this.source = this.audioContext.createMediaStreamSource(this.stream);

      const workletName = "audio-recorder-worklet";
      const src = createWorketFromSrc(workletName, AudioRecordingWorklet);

      await this.audioContext.audioWorklet.addModule(src);
      this.recordingWorklet = new AudioWorkletNode(
        this.audioContext,
        workletName,
      );

      this.recordingWorklet.port.onmessage = async (ev: MessageEvent) => {
        // worklet processes recording floats and messages converted buffer
        const arrayBuffer = ev.data.data.int16arrayBuffer;

        if (arrayBuffer) {
          const arrayBufferString = arrayBufferToBase64(arrayBuffer);
          this.emit("data", arrayBufferString);
        }
      };
      this.source.connect(this.recordingWorklet);

      // vu meter worklet
      const vuWorkletName = "vu-meter";
      await this.audioContext.audioWorklet.addModule(
        createWorketFromSrc(vuWorkletName, VolMeterWorket),
      );
      this.vuWorklet = new AudioWorkletNode(this.audioContext, vuWorkletName);
      this.vuWorklet.port.onmessage = (ev: MessageEvent) => {
        this.emit("volume", ev.data.volume);
      };

      this.source.connect(this.vuWorklet);
      this.recording = true;
      resolve();
      this.starting = null;
    });
  }