Bug 1410969 - Return dict from find_paths_and_tags(); r=ahal

This will make the return value more easily extensible and will help
consumers know what the data structures represent.

MozReview-Commit-ID: DaeYsqfMW37

--HG--
extra : rebase_source : 440d16f0604b21f0ec885e1bca5066c32b18f641

testing/mach_commands.py

@@ -256,15 +256,14 @@ class Test(MachCommandBase):
         if not what:
             from tryselect.selectors.syntax import AutoTry
             at = AutoTry(self.topsrcdir, resolver, self._mach_context)
-            changed_files, changed_tags = at.find_paths_and_tags(
+            res = at.find_paths_and_tags(False, detect_paths=True)
-                False, detect_paths=True)
+            if res['paths']:
-            if changed_files:
                 print("Tests will be run based on modifications to the "
-                      "following files:\n\t%s" % "\n\t".join(changed_files))
+                      "following files:\n\t%s" % "\n\t".join(res['paths']))
 
             # TODO this code is redundant with what `find_paths_and_tags` does.
             reader = self.mozbuild_reader(config_mode='empty')
-            files_info = reader.files_info(changed_files)
+            files_info = reader.files_info(res['paths'])
 
             paths, tags, flavors = set(), set(), set()
             for info in files_info.values():

tools/tryselect/selectors/syntax.py

@@ -487,7 +487,11 @@ class AutoTry(object):
                 if tags:
                     print("Pushing tests based on the following tags:\n\t%s" %
                           "\n\t".join(tags))
-        return paths, tags
+
+        return {
+            'paths': paths,
+            'tags': tags,
+        }
 
     def normalise_list(self, items, allow_subitems=False):
         rv = defaultdict(list)
@@ -585,8 +589,10 @@ class AutoTry(object):
                     kwargs[key] = defaults[key]
 
         if not any(kwargs[item] for item in ("paths", "tests", "tags")):
-            kwargs["paths"], kwargs["tags"] = self.find_paths_and_tags(kwargs["verbose"],
+            res = self.find_paths_and_tags(kwargs['verbose'],
-                                                                       kwargs["detect_paths"])
+                                           kwargs['detect_paths'])
+            kwargs['paths'] = res['paths']
+            kwargs['tags'] = res['tags']
 
         builds, platforms, tests, talos, jobs, paths, tags, extra = self.validate_args(**kwargs)