<!DOCTYPE html>
<html>
  <head>
    <title>
      audionode-connect-order.html
    </title>
    <script src="/resources/testharness.js"></script>
    <script src="/resources/testharnessreport.js"></script>
    <script src="/webaudio/resources/audit-util.js"></script>
    <script src="/webaudio/resources/audit.js"></script>
  </head>
  <body>
    <script id="layout-test-code">
      let audit = Audit.createTaskRunner();
      let sampleRate = 44100.0;
      let renderLengthSeconds = 0.125;
      let delayTimeSeconds = 0.1;

      function createSinWaveBuffer(context, lengthInSeconds, frequency) {
        let audioBuffer =
            context.createBuffer(1, lengthInSeconds * sampleRate, sampleRate);

        let n = audioBuffer.length;
        let data = audioBuffer.getChannelData(0);

        for (let i = 0; i < n; ++i) {
          data[i] = Math.sin(frequency * 2 * Math.PI * i / sampleRate);
        }

        return audioBuffer;
      }

      audit.define(
          {
            label: 'Test connections',
            description:
                'AudioNode connection order doesn\'t trigger assertion errors'
          },
          function(task, should) {
            // Create offline audio context.
            let context = new OfflineAudioContext(
                1, sampleRate * renderLengthSeconds, sampleRate);
            let toneBuffer =
                createSinWaveBuffer(context, renderLengthSeconds, 880);

            let bufferSource = context.createBufferSource();
            bufferSource.buffer = toneBuffer;
            bufferSource.connect(context.destination);

            let delay = context.createDelay();
            delay.delayTime.value = delayTimeSeconds;

            // We connect delay node to gain node before anything is connected
            // to delay node itself.  We do this because we try to trigger the
            // ASSERT which might be fired due to AudioNode connection order,
            // especially when gain node and delay node is involved e.g.
            // https://bugs.webkit.org/show_bug.cgi?id=76685.

            should(() => {
              let gain = context.createGain();
              gain.connect(context.destination);
              delay.connect(gain);
            }, 'Connecting nodes').notThrow();

            bufferSource.start(0);

            let promise = context.startRendering();

            should(promise, 'OfflineContext startRendering()')
                .beResolved()
                .then(task.done.bind(task));
          });

      audit.run();
    </script>
  </body>
</html>
