In update-w3c-test-expectations, handle failure to fetch results.

Specifically, when no layout tests are fetched for a particular build,
log a warning and continue instead of raising an exception and aborting.

I noticed this error when running the script on my workstation.

This CL also adds several TODO notes.

BUG=629275

Review-Url: https://codereview.chromium.org/2277303003
Cr-Commit-Position: refs/heads/master@{#414497}

third_party/WebKit/Tools/Scripts/webkitpy/common/net/buildbot_mock.py

@@ -31,6 +31,9 @@ from webkitpy.common.net.layouttestresults import LayoutTestResults
 from webkitpy.common.net.layouttestresults_unittest import LayoutTestResultsTest
 
 
+# TODO(qyearsley): Instead of canned results from another module, other unit
+# tests may be a little easier to understand if this returned None by default
+# when there are no canned results to return.
 class MockBuildBot(BuildBot):
 
     def __init__(self):

third_party/WebKit/Tools/Scripts/webkitpy/common/net/layouttestresults.py

@@ -51,9 +51,16 @@ class LayoutTestResult(object):
         return 'PASS' in self.actual_results()
 
     def did_run_as_expected(self):
+        # TODO(qyearsley): For correctness, this should be:
+        #     return not self._result_dict.get('is_unexpected', False)
+        # (Right now for expected results it's not added to the result dict
+        # but in theory it could be present.)
         return 'is_unexpected' not in self._result_dict
 
     def is_missing_image(self):
+        # TODO(qyearsley): Change this to:
+        #     self._result_dict.get('is_missing_image', False)
+        # The following method should likewise be changed.
         return 'is_missing_image' in self._result_dict
 
     def is_missing_text(self):

third_party/WebKit/Tools/Scripts/webkitpy/w3c/update_w3c_test_expectations.py

@@ -8,14 +8,20 @@ based on layout test failures in try jobs.
 This script is used as part of the w3c test auto-import process.
 """
 
+import logging
+
 from webkitpy.common.net.rietveld import Rietveld
-from webkitpy.common.net.buildbot import BuildBot
+from webkitpy.common.net.buildbot import BuildBot, Build
 from webkitpy.common.net.git_cl import GitCL
 from webkitpy.common.webkit_finder import WebKitFinder
 from webkitpy.w3c.test_parser import TestParser
 
+_log = logging.getLogger(__name__)
+
 
 def main(host):
+    # TODO(qyearsley): Add a "main" function to W3CExpectationsLineAdder
+    # and move most or all of this logic in there.
     host.initialize_scm()
     port = host.port_factory.get()
     expectations_file = port.path_to_generic_test_expectations_file()
@@ -72,7 +78,11 @@ class W3CExpectationsLineAdder(object):
         Collects the builder name, platform and a list of tests that did not
         run as expected.
 
+        TODO(qyearsley): Rather than taking a BuildBot object, this should use
+        the Host's BuildBot object.
+
         Args:
+            buildbot: A BuildBot object.
             builder: A Builder object.
             build: A Build object.
 
@@ -84,9 +94,13 @@ class W3CExpectationsLineAdder(object):
                     'bug': 'crbug.com/11111'
                 }
             }
+            If there are no failing results or no results could be fetched,
+            this will return an empty dict.
         """
-        results_url = buildbot.results_url(builder_name, build_number)
-        layout_test_results = buildbot.fetch_layout_test_results(results_url)
+        layout_test_results = buildbot.fetch_results(Build(builder_name, build_number))
+        if layout_test_results is None:
+            _log.warning('No results for builder %s, build %s', builder_name, build_number)
+            return {}
         platform = self._host.builders.port_name_for_builder_name(builder_name)
         result_list = layout_test_results.didnt_run_as_expected_results()
         failing_results_dict = self._generate_results_dict(platform, result_list)

third_party/WebKit/Tools/Scripts/webkitpy/w3c/update_w3c_test_expectations_unittest.py

@@ -5,8 +5,11 @@
 import unittest
 
 from webkitpy.common.host_mock import MockHost
+from webkitpy.common.net.buildbot import Build
+from webkitpy.common.net.buildbot_mock import MockBuildBot
+from webkitpy.common.net.layouttestresults import LayoutTestResult, LayoutTestResults
 from webkitpy.common.webkit_finder import WebKitFinder
-from webkitpy.common.net.layouttestresults import LayoutTestResult
+from webkitpy.layout_tests.builder_list import BuilderList
 from webkitpy.w3c.update_w3c_test_expectations import W3CExpectationsLineAdder
 
 
@@ -36,6 +39,59 @@ class UpdateW3CTestExpectationsTest(unittest.TestCase, W3CExpectationsLineAdder)
                 'one': {'expected': 'FAIL', 'actual': 'TIMEOUT', 'bug': 'crbug.com/626703'}
             }
         }
+        self.host.builders = BuilderList({
+            'mac': {'port_name': 'test-mac'},
+        })
+
+    def tearDown(self):
+        self.host = None
+
+    def test_get_failing_results_dict_only_passing_results(self):
+        self.host.buildbot.set_results(Build('mac', 123), LayoutTestResults({
+            'tests': {
+                'fake': {
+                    'test.html': {
+                        'passing-test.html': {
+                            'expected': 'PASS',
+                            'actual': 'PASS',
+                        },
+                    },
+                },
+            },
+        }))
+        line_adder = W3CExpectationsLineAdder(self.host)
+        self.assertEqual(line_adder.get_failing_results_dict(self.host.buildbot, 'mac', 123), {})
+
+    def test_get_failing_results_dict_no_results(self):
+        self.host.buildbot = MockBuildBot()
+        self.host.buildbot.set_results(Build('mac', 123), None)
+        line_adder = W3CExpectationsLineAdder(self.host)
+        self.assertEqual(line_adder.get_failing_results_dict(self.host.buildbot, 'mac', 123), {})
+
+    def test_get_failing_results_dict_some_failing_results(self):
+        self.host.buildbot.set_results(Build('mac', 123), LayoutTestResults({
+            'tests': {
+                'fake': {
+                    'test.html': {
+                        'failing-test.html': {
+                            'expected': 'PASS',
+                            'actual': 'IMAGE',
+                            'is_unexpected': True,
+                        },
+                    },
+                },
+            },
+        }))
+        line_adder = W3CExpectationsLineAdder(self.host)
+        self.assertEqual(line_adder.get_failing_results_dict(self.host.buildbot, 'mac', 123), {
+            'fake/test.html/failing-test.html': {
+                'Mac': {
+                    'actual': 'IMAGE',
+                    'expected': 'PASS',
+                    'bug': 'crbug.com/626703',
+                },
+            },
+        })
 
     def test_merge_same_valued_keys(self):
         self.assertEqual(