Bug 1413928 - [tryselect] Add a new 'path' template r=maja_zf

This sets the MOZHARNESS_TEST_PATHS environment variables for all tasks.
When specifying paths, this will cause many test tasks to only run the
tests under that directory as opposed to the normal default.

MozReview-Commit-ID: IHRXXi5mB4G

--HG--
extra : rebase_source : e7132311641f4d36a5bff56424988fbb3ae87238

tools/tryselect/templates.py

@@ -10,12 +10,15 @@ tasks. They live under taskcluster/taskgraph/templates.
 from __future__ import absolute_import, print_function, unicode_literals
 
 import os
+import sys
 from abc import ABCMeta, abstractmethod
 from argparse import Action
 
+import mozpack.path as mozpath
 from mozbuild.base import BuildEnvironmentNotFoundException, MozbuildObject
 
 here = os.path.abspath(os.path.dirname(__file__))
+build = MozbuildObject.from_environment(cwd=here)
 
 
 class Template(object):
@@ -48,7 +51,6 @@ class Artifact(Template):
         if no_artifact:
             return
 
-        build = MozbuildObject.from_environment(cwd=here)
         try:
             if build.substs.get("MOZ_ARTIFACT_BUILDS"):
                 print("Artifact builds enabled, pass --no-artifact to disable")
@@ -59,6 +61,30 @@ class Artifact(Template):
             pass
 
 
+class Path(Template):
+
+    def add_arguments(self, parser):
+        parser.add_argument('paths', nargs='*',
+                            help='Run tasks containing tests under the specified path(s).')
+
+    def context(self, paths, **kwargs):
+        if not paths:
+            return
+
+        for p in paths:
+            if not os.path.exists(p):
+                print("error: '{}' is not a valid path.".format(p), file=sys.stderr)
+                sys.exit(1)
+
+        paths = [mozpath.relpath(mozpath.join(os.getcwd(), p), build.topsrcdir) for p in paths]
+        return {
+            'env': {
+                # can't use os.pathsep as machine splitting could be a different platform
+                'MOZHARNESS_TEST_PATHS': ':'.join(paths),
+            }
+        }
+
+
 class Environment(Template):
 
     def add_arguments(self, parser):
@@ -107,6 +133,7 @@ class Rebuild(Template):
 
 all_templates = {
     'artifact': Artifact,
+    'path': Path,
     'env': Environment,
     'rebuild': Rebuild,
 }

tools/tryselect/test/test_templates.py

@@ -23,6 +23,13 @@ TEMPLATE_TESTS = {
         ([], None),
         (['--env', 'foo=bar', '--env', 'num=10'], {'env': {'foo': 'bar', 'num': '10'}}),
     ],
+    'path': [
+        ([], None),
+        (['dom/indexedDB'], {'env': {'MOZHARNESS_TEST_PATHS': 'dom/indexedDB'}}),
+        (['dom/indexedDB', 'testing'],
+         {'env': {'MOZHARNESS_TEST_PATHS': 'dom/indexedDB:testing'}}),
+        (['invalid/path'], SystemExit),
+    ],
     'rebuild': [
         ([], None),
         (['--rebuild', '10'], {'rebuild': 10}),