Improve error message in the extension api docs build script. When the json file used to build the html documentation is unreadable or has a syntax error, gives a clear error message.

BUG=18717
TEST=Manualy tested a missing input file and a file with a syntax error.

Review URL: http://codereview.chromium.org/343052

git-svn-id: svn://svn.chromium.org/chrome/trunk/src@30620 0039d316-1c4b-4281-b951-d872f2087c98

1 files changed, 13 insertions, 3 deletions

diff --git a/chrome/common/extensions/docs/build/build.py b/chrome/common/extensions/docs/build/build.py
index 18af04c..8d55ab1 100755
--- a/chrome/common/extensions/docs/build/build.py
+++ b/chrome/common/extensions/docs/build/build.py
@@ -130,9 +130,19 @@ def FindTestShell():
                    "To specify a path to test_shell use --test-shell-path")
 
 def GetAPIModuleNames():
-  contents = open(_extension_api_json, 'r').read();
-  extension_api = json.loads(contents, encoding="ASCII")
-  return set( module['namespace'].encode() for module in extension_api)
+  try:
+    contents = open(_extension_api_json, 'r').read()
+  except IOError, msg:
+    raise Exception("Failed to read the file that defines the extensions API.  "
+                    "The specific error was: %s." % msg)
+
+  try:
+    extension_api = json.loads(contents, encoding="ASCII")
+  except ValueError, msg:
+    raise Exception("File %s has a syntax error: %s" %
+                    (_extension_api_json, msg))
+
+  return set(module['namespace'].encode() for module in extension_api)
 
 def GetStaticFileNames():
   static_files = os.listdir(_static_dir)