Gracefully handle HTTP errors from pastebin

We find that the --pastebin option to pytest sometimes fails with "HTTP
Error 400: Bad Request". We're still investigating the exact cause of
these errors, but in the meantime, a failure to upload to the pastebin
service should probably not crash pytest and cause a test failure in the
continuous-integration.

This patch catches exceptions like HTTPError that may be thrown while
trying to communicate with the pastebin service, and reports them as a
"bad response", without crashing with a backtrace or failing the entire
test suite.

1 files changed, 55 insertions, 1 deletions

diff --git a/testing/test_pastebin.py b/testing/test_pastebin.py
index 4e8bac56c..a1bc0622e 100644
--- a/testing/test_pastebin.py
+++ b/testing/test_pastebin.py
@@ -83,6 +83,47 @@ class TestPaste:
         return request.config.pluginmanager.getplugin("pastebin")
 
     @pytest.fixture
+    def mocked_urlopen_fail(self, monkeypatch):
+        """
+        monkeypatch the actual urlopen call to emulate a HTTP Error 400
+        """
+        calls = []
+
+        import urllib.error
+        import urllib.request
+
+        def mocked(url, data):
+            calls.append((url, data))
+            raise urllib.error.HTTPError(url, 400, "Bad request", None, None)
+
+        monkeypatch.setattr(urllib.request, "urlopen", mocked)
+        return calls
+
+    @pytest.fixture
+    def mocked_urlopen_invalid(self, monkeypatch):
+        """
+        monkeypatch the actual urlopen calls done by the internal plugin
+        function that connects to bpaste service, but return a url in an
+        unexpected format
+        """
+        calls = []
+
+        def mocked(url, data):
+            calls.append((url, data))
+
+            class DummyFile:
+                def read(self):
+                    # part of html of a normal response
+                    return b'View <a href="/invalid/3c0c6750bd">raw</a>.'
+
+            return DummyFile()
+
+        import urllib.request
+
+        monkeypatch.setattr(urllib.request, "urlopen", mocked)
+        return calls
+
+    @pytest.fixture
     def mocked_urlopen(self, monkeypatch):
         """
         monkeypatch the actual urlopen calls done by the internal plugin
@@ -105,6 +146,19 @@ class TestPaste:
         monkeypatch.setattr(urllib.request, "urlopen", mocked)
         return calls
 
+    def test_pastebin_invalid_url(self, pastebin, mocked_urlopen_invalid):
+        result = pastebin.create_new_paste(b"full-paste-contents")
+        assert (
+            result
+            == "bad response: invalid format ('View <a href=\"/invalid/3c0c6750bd\">raw</a>.')"
+        )
+        assert len(mocked_urlopen_invalid) == 1
+
+    def test_pastebin_http_error(self, pastebin, mocked_urlopen_fail):
+        result = pastebin.create_new_paste(b"full-paste-contents")
+        assert result == "bad response: HTTP Error 400: Bad request"
+        assert len(mocked_urlopen_fail) == 1
+
     def test_create_new_paste(self, pastebin, mocked_urlopen):
         result = pastebin.create_new_paste(b"full-paste-contents")
         assert result == "https://bpaste.net/show/3c0c6750bd"
@@ -127,4 +181,4 @@ class TestPaste:
 
         monkeypatch.setattr(urllib.request, "urlopen", response)
         result = pastebin.create_new_paste(b"full-paste-contents")
-        assert result == "bad response: something bad occurred"
+        assert result == "bad response: invalid format ('something bad occurred')"