Mash: Replaces "exe:chrome" with "service:content_browser"

services/shell/public/tools/manifest/manifest_collator.py

 #!/usr/bin/env python
 # Copyright 2016 The Chromium Authors. All rights reserved.
 # Use of this source code is governed by a BSD-style license that can be
 # found in the LICENSE file.
 
 """ A collator for Service Manifests """
 
 import argparse
 import json
 import os
 import shutil
 import sys
 import urlparse
 
+
+# Keys which are completely overridden by manifest overlays
+_MANIFEST_OVERLAY_OVERRIDE_KEYS = [
+  "display_name",
+  "process-group",
+]
+
 eater_relative = '../../../../../../tools/json_comment_eater'
 eater_relative = os.path.join(os.path.abspath(__file__), eater_relative)
 sys.path.insert(0, os.path.normpath(eater_relative))
 try:
   import json_comment_eater
 finally:
   sys.path.pop(0)
 
+
 def ParseJSONFile(filename):
   with open(filename) as json_file:
     try:
       return json.loads(json_comment_eater.Nom(json_file.read()))
-    except ValueError:
+    except ValueError as e:
       print "%s is not a valid JSON document" % filename
-      return None
+      raise e
+
 
 def MergeDicts(left, right):
   for k, v in right.iteritems():
     if k not in left:
       left[k] = v
     else:
       if isinstance(v, dict):
         assert isinstance(left[k], dict)
         MergeDicts(left[k], v)
       elif isinstance(v, list):
         assert isinstance(left[k], list)
         left[k].extend(v)
       else:
         raise "Refusing to merge conflicting non-collection values."
   return left
 
 
-def MergeBaseManifest(parent, base):
-  MergeDicts(parent["capabilities"], base["capabilities"])
+def MergeManifestOverlay(manifest, overlay):
+  MergeDicts(manifest["capabilities"], overlay["capabilities"])
 
-  if "services" in base:
-    if "services" not in parent:
-      parent["services"] = []
-    parent["services"].extend(base["services"])
+  if "services" in overlay:
+    if "services" not in manifest:
+      manifest["services"] = []
+    manifest["services"].extend(overlay["services"])
 
-  if "process-group" in base:
-    parent["process-group"] = base["process-group"]
+  for key in _MANIFEST_OVERLAY_OVERRIDE_KEYS:
+    if key in overlay:
+      manifest[key] = overlay[key]
 
 
 def main():
   parser = argparse.ArgumentParser(
       description="Collate Service Manifests.")
   parser.add_argument("--parent")
   parser.add_argument("--output")
   parser.add_argument("--name")
-  parser.add_argument("--base-manifest", default=None)
+  parser.add_argument("--overlays", nargs="+", dest="overlays", default=[])
   args, children = parser.parse_known_args()
 
   parent = ParseJSONFile(args.parent)
-  if parent == None:
-    return 1
-
-  if args.base_manifest:
-    base = ParseJSONFile(args.base_manifest)
-    if base == None:
-      return 1
-    MergeBaseManifest(parent, base)
 
   service_path = parent['name'].split(':')[1]
   if service_path.startswith('//'):
     raise ValueError("Service name path component '%s' must not start " \
                      "with //" % service_path)
 
   if args.name != service_path:
     raise ValueError("Service name '%s' specified in build file does not " \
                      "match name '%s' specified in manifest." %
                      (args.name, service_path))
 
   services = []
   for child in children:
-    service = ParseJSONFile(child)
-    if service == None:
-      return 1
-    services.append(service)
+    services.append(ParseJSONFile(child))
 
   if len(services) > 0:
     parent['services'] = services
 
+  for overlay_path in args.overlays:
+    MergeManifestOverlay(parent, ParseJSONFile(overlay_path))
+
   with open(args.output, 'w') as output_file:
     json.dump(parent, output_file)
 
   return 0
 
 if __name__ == "__main__":
   sys.exit(main())