[modules/memory] Re-enable memory usage module

Add module that shows RAM consumption and opens the gnome-system-monitor
on click.

see #23

tests/modules/test_memory.py

@@ -0,0 +1,47 @@
+# pylint: disable=C0103,C0111
+
+import json
+import unittest
+import mock
+
+import bumblebee.input
+from bumblebee.input import I3BarInput
+from bumblebee.modules.memory import Module
+from tests.util import MockEngine, MockConfig, assertPopen, assertMouseEvent, assertStateContains
+
+class VirtualMemory(object):
+    def __init__(self, percent):
+        self.percent = percent
+
+class TestMemoryModule(unittest.TestCase):
+    def setUp(self):
+        self.engine = MockEngine()
+        self.engine.input = I3BarInput()
+        self.engine.input.need_event = True
+        self.config = MockConfig()
+        self.module = Module(engine=self.engine, config={ "config": self.config })
+
+    @mock.patch("select.select")
+    @mock.patch("subprocess.Popen")
+    @mock.patch("sys.stdin")
+    def test_leftclick(self, mock_input, mock_output, mock_select):
+        assertMouseEvent(mock_input, mock_output, mock_select, self.engine,
+            self.module, bumblebee.input.LEFT_MOUSE,
+            "gnome-system-monitor"
+        )
+
+    @mock.patch("psutil.virtual_memory")
+    def test_warning(self, mock_vmem):
+        self.config.set("memory.critical", "80")
+        self.config.set("memory.warning", "70")
+        mock_vmem.return_value = VirtualMemory(75)
+        assertStateContains(self, self.module, "warning")
+
+    @mock.patch("psutil.virtual_memory")
+    def test_critical(self, mock_vmem):
+        self.config.set("memory.critical", "80")
+        self.config.set("memory.warning", "70")
+        mock_vmem.return_value = VirtualMemory(85)
+        assertStateContains(self, self.module, "critical")
+
+# vim: tabstop=8 expandtab shiftwidth=4 softtabstop=4