1 files changed, 66 insertions, 0 deletions
diff --git a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
index d7069493008..d61d8e14932 100644
--- a/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
+++ b/tests/wpt/web-platform-tests/webrtc/RTCRtpParameters-helper.js
@@ -242,3 +242,69 @@ function validateCodecParameters(codec) {
   assert_optional_unsigned_int_field(codec, 'channels');
   assert_optional_string_field(codec, 'sdpFmtpLine');
 }
+
+// Get the first encoding in param.encodings.
+// Asserts that param.encodings has at least one element.
+function getFirstEncoding(param) {
+  const {
+    encodings
+  } = param;
+  assert_equals(encodings.length, 1);
+  return encodings[0];
+}
+
+// Helper function to test that modifying an encoding field should succeed
+function test_modified_encoding(kind, field, value1, value2, desc) {
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {
+      sender
+    } = pc.addTransceiver(kind, {
+      sendEncodings: [{
+        [field]: value1
+      }]
+    });
+    await doOfferAnswerExchange(t, pc);
+
+    const param1 = sender.getParameters();
+    validateSenderRtpParameters(param1);
+    const encoding1 = getFirstEncoding(param1);
+
+    assert_equals(encoding1[field], value1);
+    encoding1[field] = value2;
+
+    await sender.setParameters(param1);
+    const param2 = sender.getParameters();
+    validateSenderRtpParameters(param2);
+    const encoding2 = getFirstEncoding(param2);
+    assert_equals(encoding2[field], value2);
+  }, desc + ' with RTCRtpTransceiverInit');
+
+  promise_test(async t => {
+    const pc = new RTCPeerConnection();
+    t.add_cleanup(() => pc.close());
+    const {
+      sender
+    } = pc.addTransceiver(kind);
+    await doOfferAnswerExchange(t, pc);
+
+    const initParam = sender.getParameters();
+    validateSenderRtpParameters(initParam);
+    initParam.encodings[0][field] = value1;
+    await sender.setParameters(initParam);
+
+    const param1 = sender.getParameters();
+    validateSenderRtpParameters(param1);
+    const encoding1 = getFirstEncoding(param1);
+
+    assert_equals(encoding1[field], value1);
+    encoding1[field] = value2;
+
+    await sender.setParameters(param1);
+    const param2 = sender.getParameters();
+    validateSenderRtpParameters(param2);
+    const encoding2 = getFirstEncoding(param2);
+    assert_equals(encoding2[field], value2);
+  }, desc + ' without RTCRtpTransceiverInit');
+}
+\ No newline at end of file