Warn about missing long description (#69)

Additionally, add comprehensive tests for the disutils integration.

Resolves #64

readme_renderer/integration/distutils.py

@@ -26,6 +26,13 @@ def check_restructuredtext(self):
         Checks if the long string fields are reST-compliant.
         """
         data = self.distribution.get_long_description()
+
+        # None or empty string should both trigger this branch.
+        if not data or data == 'UNKNOWN':
+            self.warn(
+                "The project's long_description is either missing or empty.")
+            return
+
         stream = io.StringIO()
         markup = render(data, stream=stream)
 
@@ -35,4 +42,6 @@ def check_restructuredtext(self):
             self.warn(line)
 
         if markup is None:
-            self.warn("Invalid markup which will not be rendered on PyPI.")
+            self.warn(
+                "The project's long_description has invalid markup which will "
+                "not be rendered on PyPI.")

tests/test_integration_distutils.py

@@ -0,0 +1,56 @@
+import distutils.dist
+
+import mock
+
+import readme_renderer.integration.distutils
+
+
+def test_valid_rst():
+    dist = distutils.dist.Distribution(attrs=dict(
+        long_description="Hello, I am some text."))
+    checker = readme_renderer.integration.distutils.Check(dist)
+    checker.warn = mock.Mock()
+
+    checker.check_restructuredtext()
+
+    checker.warn.assert_not_called()
+
+
+def test_invalid_rst():
+    dist = distutils.dist.Distribution(attrs=dict(
+        long_description="Hello, I am some `totally borked< text."))
+    checker = readme_renderer.integration.distutils.Check(dist)
+    checker.warn = mock.Mock()
+
+    checker.check_restructuredtext()
+
+    # Should warn once for the syntax error, and finally to warn that the
+    # overall syntax is invalid
+    checker.warn.call_count = 2
+    message_one = checker.warn.call_args_list[0][0][0]
+    assert 'start-string without end-string' in message_one
+    message_two = checker.warn.call_args_list[1][0][0]
+    assert 'invalid markup' in message_two
+
+
+def test_invalid_missing():
+    dist = distutils.dist.Distribution(attrs=dict())
+    checker = readme_renderer.integration.distutils.Check(dist)
+    checker.warn = mock.Mock()
+
+    checker.check_restructuredtext()
+
+    checker.warn.assert_called_once_with(mock.ANY)
+    assert 'missing' in checker.warn.call_args[0][0]
+
+
+def test_invalid_empty():
+    dist = distutils.dist.Distribution(attrs=dict(
+        long_description=""))
+    checker = readme_renderer.integration.distutils.Check(dist)
+    checker.warn = mock.Mock()
+
+    checker.check_restructuredtext()
+
+    checker.warn.assert_called_once_with(mock.ANY)
+    assert 'missing' in checker.warn.call_args[0][0]

tox.ini

@@ -5,6 +5,7 @@ envlist = py27,pypy,py34,py35,py36,pep8,py2pep8,packaging
 extras = gfm
 deps =
     pytest
+    mock
 commands =
     py.test --strict {posargs}