[core/output] Add initial version of i3bar output

Add output handler for i3bar protocol and add some tests for it. Right
now, it only support start and end.

see #23

tests/test_engine.py

@@ -10,8 +10,8 @@ class TestEngine(unittest.TestCase):
         self.testModule = "test"
         self.testModuleSpec = "bumblebee.modules.{}".format(self.testModule)
         self.testModules = [
-            { "module": "test", "name": "a" },
-            { "module": "test", "name": "b" },
+            {"module": "test", "name": "a"},
+            {"module": "test", "name": "b"},
         ]
 
     def test_stop(self):
@@ -27,8 +27,8 @@ class TestEngine(unittest.TestCase):
         modules = self.engine.load_modules(self.testModules)
         self.assertEquals(len(modules), len(self.testModules))
         self.assertEquals(
-            [ module.__module__ for module in modules ],
-            [ self.testModuleSpec for module in modules ]
+            [module.__module__ for module in modules],
+            [self.testModuleSpec for module in modules]
         )
 
 # vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4

tests/test_i3baroutput.py

@@ -0,0 +1,28 @@
+# pylint: disable=C0103,C0111
+import json
+import unittest
+import mock
+try:
+    from StringIO import StringIO
+except ImportError:
+    from io import StringIO
+
+from bumblebee.output import I3BarOutput
+
+class TestI3BarOutput(unittest.TestCase):
+    def setUp(self):
+        self.output = I3BarOutput()
+        self.expectedStart = json.dumps({"version": 1, "click_events": True}) + "[\n"
+        self.expectedStop = "]\n"
+
+    @mock.patch("sys.stdout", new_callable=StringIO)
+    def test_start(self, stdout):
+        self.output.start()
+        self.assertEquals(self.expectedStart, stdout.getvalue())
+
+    @mock.patch("sys.stdout", new_callable=StringIO)
+    def test_stop(self, stdout):
+        self.output.stop()
+        self.assertEquals(self.expectedStop, stdout.getvalue())
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4