From 31e740ed055dabb84c743d1e390d56b62f6e0264 Mon Sep 17 00:00:00 2001
From: Joey Pinhas <joey.pinhas@datadoghq.com>
Date: Sun, 15 Sep 2019 13:48:00 -0400
Subject: [PATCH] Use unified_diff

---
 pre_commit_hooks/pretty_format_json.py |  2 +-
 tests/pretty_format_json_test.py       | 32 ++++++++++++++------------
 2 files changed, 18 insertions(+), 16 deletions(-)

diff --git a/pre_commit_hooks/pretty_format_json.py b/pre_commit_hooks/pretty_format_json.py
index 3967c30..f5476a5 100644
--- a/pre_commit_hooks/pretty_format_json.py
+++ b/pre_commit_hooks/pretty_format_json.py
@@ -59,7 +59,7 @@ def parse_topkeys(s):  # type: (str) -> List[str]
 def get_diff(source, target):  # type: (str, str) -> str
     source_lines = source.splitlines(True)
     target_lines = target.splitlines(True)
-    diff = ''.join(difflib.ndiff(source_lines, target_lines))
+    diff = ''.join(difflib.unified_diff(source_lines, target_lines))
     return diff
 
 
diff --git a/tests/pretty_format_json_test.py b/tests/pretty_format_json_test.py
index 04e4614..396c5e4 100644
--- a/tests/pretty_format_json_test.py
+++ b/tests/pretty_format_json_test.py
@@ -111,22 +111,24 @@ def test_diffing_output(capsys):
     resource_path = get_resource_path('not_pretty_formatted_json.json')
     expected_retval = 1
     expected_out = '''\
-  {
--     "foo":
--     "bar",
--         "alist": [2, 34, 234],
-+   "alist": [
-+     2,
-+     34,
-+     234
-+   ],
--   "blah": null
-+   "blah": null,
-?               +
-+   "foo": "bar"
-  }
+---
++++
+@@ -1,6 +1,9 @@
+ {
+-    "foo":
+-    "bar",
+-        "alist": [2, 34, 234],
+-  "blah": null
++  "alist": [
++    2,
++    34,
++    234
++  ],
++  "blah": null,
++  "foo": "bar"
+ }
 
-'''
+'''  # noqa: W291
     expected_err = 'File {} is not pretty-formatted\n'.format(resource_path)
 
     actual_retval = main([resource_path])