fixed tests

test_xvfb.py

@@ -28,8 +28,8 @@ class TestXvfb(unittest.TestCase):
         xvfb.start()
         self.assertNotEqual(orig_display, os.environ['DISPLAY'])
         xvfb.stop()
-        self.assertIsNone(xvfb.proc)
         self.assertEqual(orig_display, os.environ['DISPLAY'])
+        self.assertIsNone(xvfb.proc)
 
     def test_start_without_existing_display(self):
         del os.environ['DISPLAY']
@@ -47,8 +47,8 @@ class TestXvfb(unittest.TestCase):
             display_var = ':{}'.format(xvfb.new_display)
             self.assertEqual(display_var, os.environ['DISPLAY'])
             self.assertIsNotNone(xvfb.proc)
-        self.assertIsNone(xvfb.proc)
         self.assertEqual(orig_display, os.environ['DISPLAY'])
+        self.assertIsNone(xvfb.proc)
 
     def test_start_with_kwargs(self):
         w = 800
@@ -64,10 +64,15 @@ class TestXvfb(unittest.TestCase):
         self.assertEqual(display_var, os.environ['DISPLAY'])
         self.assertIsNotNone(xvfb.proc)
 
-    def test_start_with_arbitrary_kwarg(self):
+    def test_start_with_arbitrary_kwargs(self):
         xvfb = Xvfb(nolisten='tcp')
         self.addCleanup(xvfb.stop)
         xvfb.start()
         display_var = ':{}'.format(xvfb.new_display)
         self.assertEqual(display_var, os.environ['DISPLAY'])
         self.assertIsNotNone(xvfb.proc)
+
+    def test_start_fails_with_unknown_kwargs(self):
+        xvfb = Xvfb(foo='bar')
+        with self.assertRaises(RuntimeError):
+            xvfb.start()

xvfbwrapper.py

@@ -68,8 +68,11 @@ class Xvfb:
         else:
             self._set_display_var(self.orig_display)
         if self.proc is not None:
-            self.proc.terminate()
-            self.proc.wait()
+            try:
+                self.proc.terminate()
+                self.proc.wait()
+            except OSError:
+                pass
             self.proc = None
 
     def _get_next_unused_display(self):
@@ -81,11 +84,11 @@ class Xvfb:
         highest_display = max(existing_displays) if existing_displays else 0
         return highest_display + 1
 
+    def _set_display_var(self, display):
+        os.environ['DISPLAY'] = ':{}'.format(display)
+
     def xvfb_exists(self):
         """Check that Xvfb is available on PATH and is executable."""
         paths = os.environ['PATH'].split(os.pathsep)
         return any(os.access(os.path.join(path, 'Xvfb'), os.X_OK)
                    for path in paths)
-
-    def _set_display_var(self, display):
-        os.environ['DISPLAY'] = ':{}'.format(display)