bluetooth: Use sequential_promise_test to stop test from running in parallel.

LayoutTests/bluetooth/requestDevice.html

Index: LayoutTests/bluetooth/requestDevice.html
diff --git a/LayoutTests/bluetooth/requestDevice.html b/LayoutTests/bluetooth/requestDevice.html
index c4e712cfa4a9fad4eb2a84d11b00f6b21ed2a1b8..7a394c6b37f6bebbf25d3372e30277b6fdb5c330 100644
--- a/LayoutTests/bluetooth/requestDevice.html
+++ b/LayoutTests/bluetooth/requestDevice.html
@@ -2,41 +2,74 @@
 <script src="../resources/testharness.js"></script>
 <script src="../resources/testharnessreport.js"></script>
 <script>
+var lock = false;
+var testQueue = [];
+
+var getLock = function(test) {

[esprehn, 2015/04/08 00:10:29]

function getLock, no need for the var.

+  if (lock) {
+    testQueue.push(test);
+  } else {
+    lock = true;
+    test();
+  }
+};
+
+var releaseLock = function() {

[esprehn, 2015/04/08 00:10:29]

function releaseLock()

+  var nextTest = testQueue.shift();
+  if (nextTest) {
+    nextTest();

[Jeffrey Yasskin, 2015/04/07 23:46:38]

Probably use `Promise.resolve().then(nextTest)` or `setTimeout(nextTest, 0)` to
avoid calling the next test recursively.

+  } else {
+    lock = false;
+  }
+};
 
 test(function(t) { assert_exists(window, "testRunner"); t.done(); },
      "window.testRunner is required for the following tests.");
 
-async_test(function(t) {
-  testRunner.setBluetoothMockDataSet('RejectRequestDevice_NotFoundError');
-  navigator.bluetooth.requestDevice()
-    .then(
-      t.step_func(function() { assert_unreached('Mock was set to reject.'); }),
-      t.step_func(function(e) {
-        assert_equals(e.name, 'NotFoundError');
-        t.done();
-  }));
-}, 'Reject with NotFoundError.');
-
-async_test(function(t) {
-  testRunner.setBluetoothMockDataSet('RejectRequestDevice_SecurityError');
-  navigator.bluetooth.requestDevice()
-    .then(
-      t.step_func(function() { assert_unreached('Mock was set to reject.'); }),
-      t.step_func(function(e) {
-        assert_equals(e.name, 'SecurityError');
-        t.done();
-  }));
-}, 'Reject with SecurityError.');
+getLock(function(t) {

[Jeffrey Yasskin, 2015/04/07 23:46:38]

I'm not sure the test will wait for all of the tests if async_test isn't called
synchronously. Maybe call getLock inside async_test?

async_test(function(t) {
  getLock(function() {
    testRunner.setBluetoothMockDataSet...
  });
});

+  async_test(function(t) {
+    testRunner.setBluetoothMockDataSet('RejectRequestDevice_NotFoundError');

[Jeffrey Yasskin, 2015/04/07 23:46:38]

If this throws, it'll hang the test. It'd be better to incorporate the locking
into async_test and step_func, but we may also have a guarantee that the
relevant functions here don't throw.

+    navigator.bluetooth.requestDevice()
+      .then(
+	t.step_func(function() {
+          releaseLock();
+          assert_unreached('Mock was set to reject.'); }),
+	t.step_func(function(e) {
+          releaseLock();
+          assert_equals(e.name, 'NotFoundError');
+          t.done();
+	}));
+  }, 'Reject with NotFoundError.')});
 
-async_test(function(t) {
-  testRunner.setBluetoothMockDataSet('Single Empty Device');
-  navigator.bluetooth.requestDevice()
-    .then(
-      t.step_func(function(device) {
-        assert_equals(device.constructor.name, "BluetoothDevice");
-        t.done();
-      }),
-      t.step_func(function() { assert_unreached('Mock was set to resolve.'); }));
-}, 'Mock will resolve.');
+getLock(function(t) {
+  async_test(function(t) {
+    testRunner.setBluetoothMockDataSet('RejectRequestDevice_SecurityError');
+    navigator.bluetooth.requestDevice()
+      .then(
+	t.step_func(function() {
+          releaseLock();
+	  assert_unreached('Mock was set to reject.');
+	}),
+	t.step_func(function(e) {
+          releaseLock();
+          assert_equals(e.name, 'SecurityError');
+          t.done();
+	}));
+  }, 'Reject with SecurityError.')});
 
+getLock(function(t) {
+  async_test(function(t) {
+    testRunner.setBluetoothMockDataSet('Single Empty Device');
+    navigator.bluetooth.requestDevice()
+      .then(
+	t.step_func(function(device) {
+          releaseLock();
+          assert_equals(device.constructor.name, "BluetoothDevice");
+          t.done();
+	}),
+	t.step_func(function() {
+          releaseLock();
+	  assert_unreached('Mock was set to resolve.');
+	}));
+  }, 'Mock will resolve.')});
 </script>