1 files changed, 319 insertions, 0 deletions
diff --git a/dom/media/webaudio/test/webaudio.js b/dom/media/webaudio/test/webaudio.js
new file mode 100644
index 0000000000..dd8ce7fc54
--- /dev/null
+++ b/dom/media/webaudio/test/webaudio.js
@@ -0,0 +1,319 @@
+// Helpers for Web Audio tests
+
+function expectException(func, exceptionCode) {
+  var threw = false;
+  try {
+    func();
+  } catch (ex) {
+    threw = true;
+    is(ex.constructor.name, "DOMException", "Expect a DOM exception");
+    is(ex.code, exceptionCode, "Expect the correct exception code");
+  }
+  ok(threw, "The exception was thrown");
+}
+
+function expectNoException(func) {
+  var threw = false;
+  try {
+    func();
+  } catch (ex) {
+    threw = true;
+  }
+  ok(!threw, "An exception was not thrown");
+}
+
+function expectTypeError(func) {
+  var threw = false;
+  try {
+    func();
+  } catch (ex) {
+    threw = true;
+    ok(ex instanceof TypeError, "Expect a TypeError");
+  }
+  ok(threw, "The exception was thrown");
+}
+
+function expectRejectedPromise(that, func, exceptionName) {
+  var promise = that[func]();
+
+  ok(promise instanceof Promise, "Expect a Promise");
+
+  promise
+    .then(function (res) {
+      ok(false, "Promise resolved when it should have been rejected.");
+    })
+    .catch(function (err) {
+      is(
+        err.name,
+        exceptionName,
+        "Promise correctly reject with " + exceptionName
+      );
+    });
+}
+
+function fuzzyCompare(a, b) {
+  return Math.abs(a - b) < 9e-3;
+}
+
+function compareChannels(
+  buf1,
+  buf2,
+  /*optional*/ length,
+  /*optional*/ sourceOffset,
+  /*optional*/ destOffset,
+  /*optional*/ skipLengthCheck
+) {
+  if (!skipLengthCheck) {
+    is(buf1.length, buf2.length, "Channels must have the same length");
+  }
+  sourceOffset = sourceOffset || 0;
+  destOffset = destOffset || 0;
+  if (length == undefined) {
+    length = buf1.length - sourceOffset;
+  }
+  var difference = 0;
+  var maxDifference = 0;
+  var firstBadIndex = -1;
+  for (var i = 0; i < length; ++i) {
+    if (!fuzzyCompare(buf1[i + sourceOffset], buf2[i + destOffset])) {
+      difference++;
+      maxDifference = Math.max(
+        maxDifference,
+        Math.abs(buf1[i + sourceOffset] - buf2[i + destOffset])
+      );
+      if (firstBadIndex == -1) {
+        firstBadIndex = i;
+      }
+    }
+  }
+
+  is(
+    difference,
+    0,
+    "maxDifference: " +
+      maxDifference +
+      ", first bad index: " +
+      firstBadIndex +
+      " with test-data offset " +
+      sourceOffset +
+      " and expected-data offset " +
+      destOffset +
+      "; corresponding values " +
+      buf1[firstBadIndex + sourceOffset] +
+      " and " +
+      buf2[firstBadIndex + destOffset] +
+      " --- differences"
+  );
+}
+
+function compareBuffers(got, expected) {
+  if (got.numberOfChannels != expected.numberOfChannels) {
+    is(
+      got.numberOfChannels,
+      expected.numberOfChannels,
+      "Correct number of buffer channels"
+    );
+    return;
+  }
+  if (got.length != expected.length) {
+    is(got.length, expected.length, "Correct buffer length");
+    return;
+  }
+  if (got.sampleRate != expected.sampleRate) {
+    is(got.sampleRate, expected.sampleRate, "Correct sample rate");
+    return;
+  }
+
+  for (var i = 0; i < got.numberOfChannels; ++i) {
+    compareChannels(
+      got.getChannelData(i),
+      expected.getChannelData(i),
+      got.length,
+      0,
+      0,
+      true
+    );
+  }
+}
+
+/**
+ * Compute the root mean square (RMS,
+ * <http://en.wikipedia.org/wiki/Root_mean_square>) of a channel of a slice
+ * (defined by `start` and `end`) of an AudioBuffer.
+ *
+ * This is useful to detect that a buffer is noisy or silent.
+ */
+function rms(audiobuffer, channel = 0, start = 0, end = audiobuffer.length) {
+  var buffer = audiobuffer.getChannelData(channel);
+  var rms = 0;
+  for (var i = start; i < end; i++) {
+    rms += buffer[i] * buffer[i];
+  }
+
+  rms /= buffer.length;
+  rms = Math.sqrt(rms);
+  return rms;
+}
+
+function getEmptyBuffer(context, length) {
+  return context.createBuffer(
+    gTest.numberOfChannels,
+    length,
+    context.sampleRate
+  );
+}
+
+/**
+ * This function assumes that the test file defines a single gTest variable with
+ * the following properties and methods:
+ *
+ * + numberOfChannels: optional property which specifies the number of channels
+ *                     in the output.  The default value is 2.
+ * + createGraph: mandatory method which takes a context object and does
+ *                everything needed in order to set up the Web Audio graph.
+ *                This function returns the node to be inspected.
+ * + createGraphAsync: async version of createGraph.  This function takes
+ *                     a callback which should be called with an argument
+ *                     set to the node to be inspected when the callee is
+ *                     ready to proceed with the test.  Either this function
+ *                     or createGraph must be provided.
+ * + createExpectedBuffers: optional method which takes a context object and
+ *                          returns either one expected buffer or an array of
+ *                          them, designating what is expected to be observed
+ *                          in the output.  If omitted, the output is expected
+ *                          to be silence.  All buffers must have the same
+ *                          length, which must be a bufferSize supported by
+ *                          ScriptProcessorNode.  This function is guaranteed
+ *                          to be called before createGraph.
+ * + length: property equal to the total number of frames which we are waiting
+ *           to see in the output, mandatory if createExpectedBuffers is not
+ *           provided, in which case it must be a bufferSize supported by
+ *           ScriptProcessorNode (256, 512, 1024, 2048, 4096, 8192, or 16384).
+ *           If createExpectedBuffers is provided then this must be equal to
+ *           the number of expected buffers * the expected buffer length.
+ *
+ * + skipOfflineContextTests: optional. when true, skips running tests on an offline
+ *                            context by circumventing testOnOfflineContext.
+ */
+function runTest() {
+  function done() {
+    SimpleTest.finish();
+  }
+
+  SimpleTest.waitForExplicitFinish();
+  function runTestFunction() {
+    if (!gTest.numberOfChannels) {
+      gTest.numberOfChannels = 2; // default
+    }
+
+    var testLength;
+
+    function runTestOnContext(context, callback, testOutput) {
+      if (!gTest.createExpectedBuffers) {
+        // Assume that the output is silence
+        var expectedBuffers = getEmptyBuffer(context, gTest.length);
+      } else {
+        var expectedBuffers = gTest.createExpectedBuffers(context);
+      }
+      if (!(expectedBuffers instanceof Array)) {
+        expectedBuffers = [expectedBuffers];
+      }
+      var expectedFrames = 0;
+      for (var i = 0; i < expectedBuffers.length; ++i) {
+        is(
+          expectedBuffers[i].numberOfChannels,
+          gTest.numberOfChannels,
+          "Correct number of channels for expected buffer " + i
+        );
+        expectedFrames += expectedBuffers[i].length;
+      }
+      if (gTest.length && gTest.createExpectedBuffers) {
+        is(expectedFrames, gTest.length, "Correct number of expected frames");
+      }
+
+      if (gTest.createGraphAsync) {
+        gTest.createGraphAsync(context, function (nodeToInspect) {
+          testOutput(nodeToInspect, expectedBuffers, callback);
+        });
+      } else {
+        testOutput(gTest.createGraph(context), expectedBuffers, callback);
+      }
+    }
+
+    function testOnNormalContext(callback) {
+      function testOutput(nodeToInspect, expectedBuffers, callback) {
+        testLength = 0;
+        var sp = context.createScriptProcessor(
+          expectedBuffers[0].length,
+          gTest.numberOfChannels,
+          0
+        );
+        nodeToInspect.connect(sp);
+        sp.onaudioprocess = function (e) {
+          var expectedBuffer = expectedBuffers.shift();
+          testLength += expectedBuffer.length;
+          compareBuffers(e.inputBuffer, expectedBuffer);
+          if (!expectedBuffers.length) {
+            sp.onaudioprocess = null;
+            callback();
+          }
+        };
+      }
+      var context = new AudioContext();
+      runTestOnContext(context, callback, testOutput);
+    }
+
+    function testOnOfflineContext(callback, sampleRate) {
+      function testOutput(nodeToInspect, expectedBuffers, callback) {
+        nodeToInspect.connect(context.destination);
+        context.oncomplete = function (e) {
+          var samplesSeen = 0;
+          while (expectedBuffers.length) {
+            var expectedBuffer = expectedBuffers.shift();
+            is(
+              e.renderedBuffer.numberOfChannels,
+              expectedBuffer.numberOfChannels,
+              "Correct number of input buffer channels"
+            );
+            for (var i = 0; i < e.renderedBuffer.numberOfChannels; ++i) {
+              compareChannels(
+                e.renderedBuffer.getChannelData(i),
+                expectedBuffer.getChannelData(i),
+                expectedBuffer.length,
+                samplesSeen,
+                undefined,
+                true
+              );
+            }
+            samplesSeen += expectedBuffer.length;
+          }
+          callback();
+        };
+        context.startRendering();
+      }
+
+      var context = new OfflineAudioContext(
+        gTest.numberOfChannels,
+        testLength,
+        sampleRate
+      );
+      runTestOnContext(context, callback, testOutput);
+    }
+
+    testOnNormalContext(function () {
+      if (!gTest.skipOfflineContextTests) {
+        testOnOfflineContext(function () {
+          testOnOfflineContext(done, 44100);
+        }, 48000);
+      } else {
+        done();
+      }
+    });
+  }
+
+  if (document.readyState !== "complete") {
+    addLoadEvent(runTestFunction);
+  } else {
+    runTestFunction();
+  }
+}