Add the JS data pipe client to be used to implement serial send.

extensions/test/data/data_sender_unittest.js

+// Copyright 2014 The Chromium Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style license that can be
+// found in the LICENSE file.
+
+// Tests launched by extensions/renderer/api/serial/data_sender_unittest.cc
+
+var test = require('test').binding;
+var unittestBindings = require('test_environment_specific_bindings');
+
+var BUFFER_SIZE = 10;
+var FATAL_ERROR = 2;
+
+function generateData(size, character) {
+  if (!character)
+    character = 'a';
+  var buffer = new ArrayBuffer(size);
+  var intView = new Int8Array(buffer);
+  for (var i = 0; i < size; i++) {
+    intView[i] = character.charCodeAt(0);
+  }
+  return buffer;
+}
+
+function createSender() {
+  return Promise.all([
+    requireAsync('content/public/renderer/service_provider'),
+    requireAsync('data_sender'),
+    requireAsync('device/serial/data_stream.mojom'),
+  ]).then(test.callbackPass(function(modules) {
+    var serviceProvider = modules[0];
+    var dataSender = modules[1];
+    var dataStream = modules[2];
+    return new dataSender.DataSender(
+        serviceProvider.connectToService(dataStream.DataSinkProxy.NAME_),
+        BUFFER_SIZE,
+        FATAL_ERROR);
+  }));
+}
+
+unittestBindings.exportTests([
+  function testSend() {
+    createSender().then(test.callbackPass(function(sender) {
+      var seen = null;
+      sender.send(generateData(1)).then(test.callbackPass(function(bytesSent) {
+        test.assertEq(1, bytesSent);
+        test.assertEq(null, seen);
+        seen = 'first';
+      }));
+      sender.send(generateData(1)).then(test.callbackPass(function(bytesSent) {
+        sender.close();
+        test.assertEq(1, bytesSent);
+        test.assertEq('first', seen);
+        seen = 'second';
+      }));
+    }));
+  },
+
+  function testLargeSend() {

[benwells, 2014/08/20 06:13:47]

Could you also add a test which sends heterogenous data > buffer size? E.g.
"abcdefghijklmnopqrstuvwxyz".

[Sam McNally, 2014/08/20 06:30:56]

Done.

+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(BUFFER_SIZE * 100)).then(test.callbackPass(
+          function(bytesSent) {
+        test.assertEq(BUFFER_SIZE * 100, bytesSent);
+        sender.close();
+      }));
+    }));
+  },
+
+  function testSendError() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(BUFFER_SIZE * 100, 'b')).catch(test.callbackPass(
+          function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(0, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testSendErrorPartialSuccess() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(BUFFER_SIZE * 100, 'b')).catch(test.callbackPass(
+          function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(5, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testSendErrorBetweenPackets() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(2, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(2, e.bytesSent);
+      }));
+      // After an error, all sends in progress will be cancelled.
+      sender.send(generateData(2, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(0, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testSendErrorInSecondPacket() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(2, 'b')).then(test.callbackPass(
+          function(bytesSent) {
+        test.assertEq(2, bytesSent);
+      }));
+      sender.send(generateData(2, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(1, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testSendErrorInLargeSend() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(BUFFER_SIZE * 100, 'b')).catch(test.callbackPass(
+          function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(2, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testSendErrorBeforeLargeSend() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.send(generateData(5, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(2, e.bytesSent);
+      }));
+      sender.send(generateData(BUFFER_SIZE * 100, 'b')).catch(test.callbackPass(
+          function(e) {
+        test.assertEq(1, e.error);
+        test.assertEq(0, e.bytesSent);
+        sender.send(generateData(1)).then(test.callbackPass(
+            function(bytesSent) {
+          test.assertEq(1, bytesSent);
+          sender.close();
+        }));
+      }));
+    }));
+  },
+
+  function testCancelWithoutSend() {
+    createSender().then(test.callbackPass(function(sender) {
+      sender.cancel(3).then(test.callbackPass(function() {
+        sender.close();
+      }));
+    }));
+  },
+
+  function testCancel() {
+    createSender().then(test.callbackPass(function(sender) {
+      var seen = null;
+      sender.send(generateData(1, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(3, e.error);
+        test.assertEq(0, e.bytesSent);
+        test.assertEq(null, seen);
+        seen = 'send';
+      }));
+      sender.cancel(3).then(test.callbackPass(function() {
+        test.assertEq('send', seen);
+        seen = 'cancel';
+        sender.close();
+      }));
+      test.assertThrows(
+          sender.cancel, sender, [], 'Cancel already in progress');
+      test.assertThrows(sender.send, sender, [], 'Cancel in progress');
+    }));
+  },
+
+  function testClose() {
+    createSender().then(test.callbackPass(function(sender) {
+      var seen = null;
+      sender.send(generateData(1, 'b')).catch(test.callbackPass(function(e) {
+        test.assertEq(FATAL_ERROR, e.error);
+        test.assertEq(0, e.bytesSent);
+        test.assertEq(null, seen);
+        seen = 'send';
+      }));
+      sender.cancel(3).then(test.callbackPass(function() {
+        test.assertEq('send', seen);
+        seen = 'cancel';
+        sender.close();
+      }));
+      sender.close();
+      test.assertThrows(
+          sender.cancel, sender, [], 'DataSender has been closed');
+      test.assertThrows(sender.send, sender, [], 'DataSender has been closed');
+    }));
+  },
+
+], test.runTests, exports);