Bug 1286900 - Ensure WPT tests have a version control checkout; r=ted

We add a mozharness action to the TestingMixin base class that ensures
we're running from a VCS checkout and we add this action to the WPT
script.

This ensures that we always have a source checkout available, even
in buildbot. (Before, we only had a source checkout in TaskCluster.)

MozReview-Commit-ID: 26NxwDZywXr

--HG--
extra : rebase_source : 6aea0390b0c9ff43972ef6fe6592f104401cc3fc

testing/mozharness/mozharness/mozilla/testing/testbase.py

@@ -9,7 +9,6 @@ import copy
 import os
 import platform
 import pprint
-import re
 import urllib2
 import json
 import socket
@@ -21,6 +20,9 @@ from mozharness.base.python import (
     VirtualenvMixin,
     virtualenv_config_options,
 )
+from mozharness.base.vcs.vcsbase import (
+    VCSMixin,
+)
 from mozharness.mozilla.buildbot import BuildbotMixin, TBPL_WARNING
 from mozharness.mozilla.proxxy import Proxxy
 from mozharness.mozilla.structuredlog import StructuredOutputParser
@@ -102,7 +104,8 @@ testing_config_options = [
 
 # TestingMixin {{{1
 class TestingMixin(VirtualenvMixin, BuildbotMixin, ResourceMonitoringMixin,
-                   TaskClusterArtifactFinderMixin, TooltoolMixin, TryToolsMixin):
+                   TaskClusterArtifactFinderMixin, TooltoolMixin, TryToolsMixin,
+                   VCSMixin):
     """
     The steps to identify + download the proper bits for [browser] unit
     tests and Talos.
@@ -120,6 +123,55 @@ class TestingMixin(VirtualenvMixin, BuildbotMixin, ResourceMonitoringMixin,
     default_tools_repo = 'https://hg.mozilla.org/build/tools'
     proxxy = None
 
+    def query_abs_dirs(self):
+        dirs = super(TestingMixin, self).query_abs_dirs()
+
+        if self.topsrcdir:
+            dirs['checkout'] = self.topsrcdir
+        else:
+            dirs['checkout'] = os.path.join(dirs['base_work_dir'], 'checkout')
+
+        if 'HG_SHARE_BASE_DIR' in os.environ:
+            dirs['hg_shared'] = os.environ['HG_SHARE_BASE_DIR']
+        else:
+            dirs['hg_shared'] = os.path.join(dirs['base_work_dir'], 'hg-shared')
+
+        return dirs
+
+    def ensure_firefox_checkout(self):
+        """Action that ensures we have a source checkout available.
+
+        If a source checkout is not available, we create one.
+        """
+        if self.topsrcdir:
+            self.info('already running from a source checkout; nothing to do')
+            return
+
+        self.info('not running from source checkout')
+
+        bb_config = getattr(self, 'buildbot_config', None)
+        if not bb_config:
+            self.fatal('buildbot config not loaded; unable to proceed '
+                       '(a buildbot config must be loaded to obtain VCS info)')
+
+        bb_props = bb_config['properties']
+
+        dirs = self.query_abs_dirs()
+
+        args = {
+            'repo': 'https://hg.mozilla.org/%s' % bb_props['repo_path'],
+            'dest': dirs['checkout'],
+            'vcs_share_base': dirs['hg_shared'],
+            'revision': bb_props['revision'],
+            'clone_with_purge': True,
+            # Always use the unified repo as the upstream because it is
+            # stored more efficiently.
+            'clone_upstream_url': 'https://hg.mozilla.org/mozilla-unified',
+        }
+
+        self.vcs_checkout(vcs='hg', **args)
+        self.topsrcdir = dirs['checkout']
+
     def _query_proxxy(self):
         """manages the proxxy"""
         if not self.proxxy:

testing/mozharness/scripts/web_platform_tests.py

@@ -58,6 +58,7 @@ class WebPlatformTest(TestingMixin, MercurialScript, BlobUploadMixin):
             all_actions=[
                 'clobber',
                 'read-buildbot-config',
+                'ensure-firefox-checkout',
                 'download-and-extract',
                 'fetch-geckodriver',
                 'create-virtualenv',