Improve run-webkit-tests error reporting when ref tests have missing images.

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/controllers/test_result_writer_unittest.py

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@@ skipping 61 matching lines @@
         failure = test_failures.FailureReftestMismatch()
         failure.reference_filename = 'notfound.html'
         written_files = self.run_test(failures=[failure], files={})
         self.assertEqual(written_files, {})
 
         failure = test_failures.FailureReftestMismatchDidNotOccur()
         failure.reference_filename = 'notfound.html'
         written_files = self.run_test(failures=[failure], files={})
         self.assertEqual(written_files, {})
 
+    def test_reftest_image_missing(self):
+        failure = test_failures.FailureReftestNoImageGenerated()
+        failure.reference_filename = '/src/exists-expected.html'
+        files = {'/src/exists-expected.html': 'yup'}
+        written_files = self.run_test(failures=[failure], files=files)
+        self.assertEqual(written_files, {'/tmp/exists-expected.html': 'yup'})
+
+        failure = test_failures.FailureReftestNoReferenceImageGenerated()
+        failure.reference_filename = '/src/exists-expected.html'
+        files = {'/src/exists-expected.html': 'yup'}
+        written_files = self.run_test(failures=[failure], files=files)
+        self.assertEqual(written_files, {'/tmp/exists-expected.html': 'yup'})

[qyearsley, 2017/03/27 23:15:09]

It's not very obvious how to interpret these tests; what does it mean when a
file is written to /tmp? Does that just mean the reference test failed?

[skobes, 2017/03/27 23:30:17]

I cargo-culted this from test_reference_exists, it's verifying that the
-expected.html file is written even when missing-image failures are passed into
write_test_result.

I suppose ideally we'd check that when only one image is missing, the other is
still written, but that requires some refactoring of run_test that I'm not sure
is worth the trouble.

+
     def test_baseline_name(self):
         fs = MockFileSystem()
         self.assertEqual(baseline_name(fs, 'x/y/foo.html', 'txt'), 'x/y/foo-expected.txt')
         self.assertEqual(baseline_name(fs, 'foo.html', 'txt'), 'foo-expected.txt')
         self.assertEqual(baseline_name(fs, 'foo', 'txt'), 'foo-expected.txt')