Add option to show expected output
This prints a diff between the given json file and the expected
(pretty) output, with this functionality hidden behind a cli flag
diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
index f42630a..475bf1c 100644
--- a/pre_commit_hooks/pretty_format_json.py
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -4,6 +4,7 @@
import io
import json
import sys
+import difflib
from collections import OrderedDict
from typing import List
from typing import Mapping
@@ -55,6 +56,14 @@
return s.split(',')
+def get_diff(source, target):
+ source_lines = ''.join(source).split('\n')
+ target_lines = ''.join(target).split('\n')
+ d = difflib.Differ()
+ diff = d.compare(source_lines, target_lines)
+ return '\n'.join(diff)
+
+
def main(argv=None): # type: (Optional[Sequence[str]]) -> int
parser = argparse.ArgumentParser()
parser.add_argument(
@@ -96,6 +105,13 @@
default=[],
help='Ordered list of keys to keep at the top of JSON hashes',
)
+ parser.add_argument(
+ '--show-expected',
+ action='store_true',
+ dest='show_expected',
+ default=False,
+ help='Show a diff between the input file and expected (pretty) output',
+ )
parser.add_argument('filenames', nargs='*', help='Filenames to fix')
args = parser.parse_args(argv)
@@ -115,16 +131,8 @@
if contents != pretty_contents:
print('File {} is not pretty-formatted'.format(json_file))
- contents_by_line = ''.join(contents).split('\n')
- pretty_contents_by_line = ''.join(pretty_contents).split('\n')
-
- diff = len(contents_by_line) - len(pretty_contents_by_line)
- if diff > 0:
- pretty_contents_by_line.extend([''] * diff)
-
- for line_num, line in enumerate(contents_by_line):
- if line != pretty_contents_by_line[line_num]:
- print('{}:{}'.format(json_file, line_num))
+ if args.show_expected:
+ print(get_diff(contents, pretty_contents))
if args.autofix:
_autofix(json_file, pretty_contents)
