Add new script jsoncheck.py

Add a new script that can reformat JSON files and check for niceness.
We can use this later as niceness check for openstack-doc-test.

Change-Id: I33c5309bfa2e1abfa6a35d1cfcdc984775e85f05

README.rst

@@ -103,6 +103,8 @@ Release notes
 * ``openstack-auto-commands``: Improved screen generation and swift
   subcommand xml output.
 * ``openstack-doc-tools``: Warn about non-breaking space.
+* New command ``openstack-jsoncheck`` to check for niceness of JSON
+  files and reformat them.
 
 0.13
 ----

os_doc_tools/jsoncheck.py

@@ -0,0 +1,122 @@
+#!/usr/bin/env python
+
+#    Licensed under the Apache License, Version 2.0 (the "License"); you may
+#    not use this file except in compliance with the License. You may obtain
+#    a copy of the License at
+#
+#         http://www.apache.org/licenses/LICENSE-2.0
+#
+#    Unless required by applicable law or agreed to in writing, software
+#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
+#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
+#    License for the specific language governing permissions and limitations
+#    under the License.
+
+"""
+
+Usage:
+    jsoncheck.py [-f] FILES
+
+Checks JSON syntax and optionally reformats (pretty-prints) the valid files.
+
+Optional:
+    - demjson Python library (better diagnostics for invalid JSON synax)
+
+"""
+
+from __future__ import print_function
+
+import argparse
+import collections
+import json
+import sys
+import textwrap
+
+try:
+    import demjson
+except ImportError:
+    demjson = None
+    sys.stderr.write("Cannot import the demjson Python module. Diagnostics "
+                     "for invalid JSON files\nwill be limited.\n")
+
+
+def indent_note(errstr):
+    """Indents and wraps a string."""
+    return textwrap.fill(errstr, initial_indent=8 * ' ',
+                         subsequent_indent=12 * ' ',
+                         width=80)
+
+
+def get_demjson_diagnostics(raw):
+    """Get diagnostics string for invalid JSON files from demjson."""
+    errstr = None
+    try:
+        demjson.decode(raw, strict=True)
+    except demjson.JSONError as err:
+        errstr = err.pretty_description()
+    return errstr
+
+
+class ParserException(Exception):
+    pass
+
+
+def parse_json(raw):
+    """Parse raw JSON file."""
+    try:
+        parsed = json.loads(raw, object_pairs_hook=collections.OrderedDict)
+    except ValueError as err:
+        note = indent_note(str(err))
+        # if demjson is available, print its diagnostic string as well
+        if demjson:
+            demerr = get_demjson_diagnostics(raw)
+            if demerr:
+                note += "\n" + indent_note(demerr)
+        raise ParserException(note)
+    else:
+        return parsed
+
+
+class FormattingException(Exception):
+    pass
+
+
+def check_format(parsed, raw, path=None):
+    """Check formatting; pretty-print JSON file while retaining key order."""
+    formatted = json.dumps(parsed, sort_keys=False, separators=(',', ': '),
+                           indent=4)
+    if formatted != raw:
+        if path:
+            with open(path, 'w') as outfile:
+                outfile.write(formatted)
+            errstr = indent_note("Reformatted")
+        else:
+            errstr = indent_note("Reformatting needed")
+        raise FormattingException(errstr)
+
+
+def main():
+    parser = argparse.ArgumentParser(description="Validate and reformat JSON"
+                                     "files.")
+    parser.add_argument('files', metavar='FILES', nargs='+')
+    parser.add_argument('-f', '--format', action='store_true',
+                        help='reformat valid JSON files')
+    args = parser.parse_args()
+
+    for path in args.files:
+        with open(path, 'r') as infile:
+            raw = infile.read()
+            infile.close()
+            try:
+                parsed = parse_json(raw)
+            except ParserException as err:
+                print("%s\n%s" % (path, err))
+            else:
+                try:
+                    check_format(parsed, raw, path if args.format else None)
+                except FormattingException as err:
+                    print("%s\n%s" % (path, err))
+
+
+if __name__ == "__main__":
+    sys.exit(main())

setup.cfg

@@ -36,6 +36,7 @@ console_scripts =
      openstack-auto-commands = os_doc_tools.commands:main
      openstack-generate-docbook = os_doc_tools.handle_pot:generatedocbook
      openstack-generate-pot = os_doc_tools.handle_pot:generatepot
+     openstack-jsoncheck = os_doc_tools.jsoncheck:main
 
 [build_sphinx]
 source-dir = doc/source