Update web-platform-tests to revision 4a5223502fa660ce03e470af6a61c8bc26c5a8ee

tests/wpt/web-platform-tests/streams/readable-streams/patched-global.js

@@ -0,0 +1,67 @@
+'use strict';
+
+// Tests which patch the global environment are kept separate to avoid
+// interfering with other tests.
+
+if (self.importScripts) {
+  self.importScripts('/resources/testharness.js');
+}
+
+const ReadableStream_prototype_locked_get =
+      Object.getOwnPropertyDescriptor(ReadableStream.prototype, 'locked').get;
+
+// Verify that |rs| passes the brand check as a readable stream.
+function isReadableStream(rs) {
+  try {
+    ReadableStream_prototype_locked_get.call(rs);
+    return true;
+  } catch (e) {
+    return false;
+  }
+}
+
+test(t => {
+  const rs = new ReadableStream();
+
+  const trappedProperties = ['highWaterMark', 'size', 'start', 'type', 'mode'];
+  for (const property of trappedProperties) {
+    // eslint-disable-next-line no-extend-native, accessor-pairs
+    Object.defineProperty(Object.prototype, property, {
+      get() { throw new Error(`${property} getter called`); },
+      configurable: true
+    });
+  }
+  t.add_cleanup(() => {
+    for (const property of trappedProperties) {
+      delete Object.prototype[property];
+    }
+  });
+
+  const [branch1, branch2] = rs.tee();
+  assert_true(isReadableStream(branch1), 'branch1 should be a ReadableStream');
+  assert_true(isReadableStream(branch2), 'branch2 should be a ReadableStream');
+}, 'ReadableStream tee() should not touch Object.prototype properties');
+
+test(t => {
+  const rs = new ReadableStream();
+
+  const oldReadableStream = self.ReadableStream;
+
+  /* eslint-disable no-native-reassign */
+  self.ReadableStream = function() {
+    throw new Error('ReadableStream called on global object');
+  };
+
+  t.add_cleanup(() => {
+    self.ReadableStream = oldReadableStream;
+  });
+
+  const [branch1, branch2] = rs.tee();
+
+  assert_true(isReadableStream(branch1), 'branch1 should be a ReadableStream');
+  assert_true(isReadableStream(branch2), 'branch2 should be a ReadableStream');
+
+  /* eslint-enable no-native-reassign */
+}, 'ReadableStream tee() should not call the global ReadableStream');
+
+done();