add specificity to test

tests/test_cli.py

@@ -88,13 +88,17 @@ def testCliDraw(self):
             os.remove('tmp.svg')
 
     def testDrawProjected(self):
-        self.invoke(['draw', self.dc, '--output', 'tmp.svg', '--precision', '10'])
+        f = os.path.expanduser('~/tmp.svg')
+        result = self.invoke(['draw', self.dc, '--output', f, '--precision', '10'])
+
+        self.assertEqual(result.exit_code, 0)
+        self.assertTrue(os.path.exists(f))
 
         try:
-            with open('tmp.svg') as f:
-                svg = f.read()
+            with open(f) as g:
+                svg = g.read()
                 match = re.search(r'points="([^"]+)"', svg)
-                assert match
+                self.assertIsNotNone(match)
 
             result = match.groups()[0]
             points = [[float(x) for x in p.split(',')] for p in result.split(' ')]
@@ -106,7 +110,7 @@ def testDrawProjected(self):
                     self.assertAlmostEqual(*z)
 
         finally:
-            os.remove('tmp.svg')
+            os.remove(f)
 
     def testCliHelp(self):
         result = self.invoke(('--help',))