1 files changed, 129 insertions, 0 deletions
diff --git a/testing/web-platform/tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletprocessor-unconnected-outputs.https.window.js b/testing/web-platform/tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletprocessor-unconnected-outputs.https.window.js
new file mode 100644
index 0000000000..16adddd339
--- /dev/null
+++ b/testing/web-platform/tests/webaudio/the-audio-api/the-audioworklet-interface/audioworkletprocessor-unconnected-outputs.https.window.js
@@ -0,0 +1,129 @@
+'use strict';
+
+// This value is used to set the values in an AudioParam.
+const TestValue = 0.5;
+
+// Prepare 4 outputs; 2 outputs will be unconnected for testing.
+const WorkletNodeOptions =  {
+  processorOptions: {testValue: TestValue},
+  numberOfInputs: 0,
+  numberOfOutputs: 4
+};
+
+// The code for the AWP definition in AudioWorkletGlobalScope.
+const processorCode = () => {
+
+  // This processor sends the `outputs` array to the main thread at the first
+  // process call - after filling its 2nd output with the test value.
+  class OutputTestProcessor extends AudioWorkletProcessor {
+
+    constructor(options) {
+      super(options);
+      this.testValue = options.processorOptions.testValue;
+    }
+
+    process(inputs, outputs) {
+      // Fill the second output of this process with the `testValue`.
+      const output = outputs[1];
+      for (const channel of output) {
+        channel.fill(this.testValue);
+      }
+
+      // Send the outputs array and stop rendering.
+      this.port.postMessage({outputs});
+      return false;
+    }
+  }
+
+  registerProcessor('output-test-processor', OutputTestProcessor);
+
+  // This process has an AudioParam and sends the `params` array to the main
+  // thread at the first process call.
+  class ParamTestProcessor extends AudioWorkletProcessor {
+    static get parameterDescriptors() {
+      return [
+        {name: 'testParam', defaultValue: 0.0}
+      ];
+    }
+
+    process(inputs, outputs, params) {
+      // Send the params array and stop rendering.
+      this.port.postMessage({paramValues: params.testParam});
+      return false;
+    }
+  }
+
+  registerProcessor('param-test-processor', ParamTestProcessor);
+}
+
+const initializeAudioContext = async () => {
+  const context = new AudioContext();
+  const moduleString = `(${processorCode.toString()})();`;
+  const blobUrl = window.URL.createObjectURL(
+      new Blob([moduleString], {type: 'text/javascript'}));
+  await context.audioWorklet.addModule(blobUrl);
+  context.suspend();
+  return context;
+};
+
+// Test if unconnected outputs provides a non-zero length array for channels.
+promise_test(async () => {
+  const context = await initializeAudioContext();
+  const outputTester = new AudioWorkletNode(
+      context, 'output-test-processor', WorkletNodeOptions);
+  const testGain = new GainNode(context);
+
+  // Connect the 2nd output of the tester to another node. Note that
+  // `testGain` is not connected to the destination.
+  outputTester.connect(testGain, 1);
+
+  // Connect the 4th output of the tester to the destination node.
+  outputTester.connect(context.destination, 3);
+
+  return new Promise(resolve => {
+    outputTester.port.onmessage = resolve;
+    context.resume();
+  }).then(event => {
+    // The number of outputs should be 4, as specified above.
+    const outputs = event.data.outputs;
+    assert_equals(outputs.length, WorkletNodeOptions.numberOfOutputs);
+    for (const output of outputs) {
+      // Each output should have 1 channel of audio data per spec.
+      assert_equals(output.length, 1);
+      for (const channel of output) {
+        // Each channel should have a non-zero length array.
+        assert_true(channel.length > 0);
+      }
+    }
+    context.close();
+  });
+}, 'Test if unconnected outputs provides a non-zero length array for channels');
+
+// Test if outputs connected to AudioParam provides a non-zero length array for
+// channels.
+promise_test(async () => {
+  const context = await initializeAudioContext();
+  const outputTester = new AudioWorkletNode(
+      context, 'output-test-processor', WorkletNodeOptions);
+  const paramTester = new AudioWorkletNode(
+      context, 'param-test-processor');
+
+  // Connect the 2nd output of the tester to another node's AudioParam.
+  outputTester.connect(paramTester.parameters.get('testParam'), 1);
+
+  outputTester.connect(context.destination);
+
+  return new Promise(resolve => {
+    paramTester.port.onmessage = resolve;
+    context.resume();
+  }).then(event => {
+    // The resulting values from AudioParam should be a non-zero length array
+    // filled with `TestValue` above.
+    const actualValues = event.data.paramValues;
+    const expectedValues = (new Array(actualValues.length)).fill(TestValue);
+    assert_true(actualValues.length > 0);
+    assert_array_equals(actualValues, expectedValues);
+    context.close();
+  });
+}, 'Test if outputs connected to AudioParam provides a non-zero length array ' +
+   'for channels');