Regenerate MANIFEST.json when WPT tests are run

third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py

Index: third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
diff --git a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
index ef62e807f288f4d51d1ca50b30d716fdb515c3f0..14ea0ea1a7909e9a791ee150081adcf045b40c57 100644
--- a/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
+++ b/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py
@@ -36,6 +36,7 @@ import difflib
 import errno
 import functools
 import json
+import hashlib
 import logging
 import optparse
 import re
@@ -739,8 +740,31 @@ class Port(object):
 
     @memoized
     def _wpt_manifest(self):
-        path = self._filesystem.join(self.layout_tests_dir(), 'external', 'wpt', 'MANIFEST.json')
-        return json.loads(self._filesystem.read_text_file(path))
+        manifest_path = self._filesystem.join(self.layout_tests_dir(), 'external', 'wpt', 'MANIFEST.json')
+
+        original_hash = self._get_manifest_hash(manifest_path)
+        self._generate_manifest()
+        updated_hash = self._get_manifest_hash(manifest_path)
+
+        if original_hash != updated_hash:
+            _log.warning('MANIFEST.json has been updated to reflect changes in external/wpt!')

[jeffcarp, 2017/01/23 22:27:51]

I spent an hour trying to write a unit test for this and couldn't quite get
there. Replacing Port._generate_manifest caused weird errors like this:

  Traceback (most recent call last):
    File
"/usr/local/google/home/jeffcarp/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base_unittest.py",
line 316, in test_warn_if_new_test_found_in_manifest
      port.tests([])
    File
"/usr/local/google/home/jeffcarp/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py",
line 670, in tests
      tests = self.real_tests(paths)
    File
"/usr/local/google/home/jeffcarp/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/layout_tests/port/base.py",
line 683, in real_tests
      skipped_directories, functools.partial(Port.is_test_file, self),
self.test_key)
    File
"/usr/local/google/home/jeffcarp/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/common/find_files.py",
line 63, in find
      filesystem, base_dir, paths), skipped_directories, file_filter,
directory_sort_key)
    File
"/usr/local/google/home/jeffcarp/chromium/src/third_party/WebKit/Tools/Scripts/webkitpy/common/find_files.py",
line 88, in _normalized_find
      for path in paths_to_walk))
  TypeError: type object argument after * must be a sequence, not generator

[jeffcarp, 2017/01/24 20:32:39]

Replacing line 269 of base_unittest.py below with this is enough to cause the
error:
port = self.make_port(with_tests=True,
executive=MockExecutive(run_command_fn=lambda: ''))

I need to mock out the call that _generate_manifest makes so that the
MANIFEST.json changes mid-run, which is why I was originally trying to replace
run_command_fn but it led to this issue. Currently looking into it.

[jeffcarp, 2017/01/24 20:42:59]

I figured it out (see newest patch). My guess is that if run_command_fn returned
anything, it caused the above code to break in that way. Returning nothing seems
to solve the problem.

+
+        return json.loads(self._filesystem.read_text_file(manifest_path))
+
+    def _get_manifest_hash(self, manifest_path):
+        hash_context = hashlib.md5()
+        manifest_buffer = self._filesystem.read_binary_file(manifest_path)
+        assert manifest_buffer
+        hash_context.update(manifest_buffer)
+        return hash_context.hexdigest()
+
+    def _generate_manifest(self):
+        wpt_path = self._webkit_finder.path_from_webkit_base('LayoutTests', 'external', 'wpt')
+        manifest_path = self._webkit_finder.path_from_webkit_base(
+            'Tools', 'Scripts', 'webkitpy', 'thirdparty', 'wpt', 'wpt', 'manifest')
+
+        _log.info('Generating MANIFEST.json')
+        self._executive.run_command([manifest_path, '--work', '--tests-root', wpt_path])
 
     def _manifest_items_for_path(self, path_in_wpt):
         """Returns a manifest item for the given WPT path, or None if not found.