Close jsondiff input files after loading documents

jsonpatch_cli.py

@@ -8,6 +8,7 @@
 import jsonpatch
 import tempfile
 import argparse
+from contextlib import ExitStack
 
 
 jsondiff_parser = argparse.ArgumentParser(
@@ -35,8 +36,12 @@ def jsondiff_main():
 def diff_files():
     """ Diffs two JSON files and prints a patch """
     args = jsondiff_parser.parse_args()
-    doc1 = json.load(args.FILE1)
-    doc2 = json.load(args.FILE2)
+    with ExitStack() as inputs:
+        for stream in (args.FILE1, args.FILE2):
+            if stream is not sys.stdin:
+                inputs.enter_context(stream)
+        doc1 = json.load(args.FILE1)
+        doc2 = json.load(args.FILE2)
     patch = jsonpatch.make_patch(doc1, doc2, generate_test_ops=args.test_ops)
     if patch.patch:
         print(json.dumps(patch.patch, indent=args.indent, ensure_ascii=not(args.preserve_unicode)))

tests.py

@@ -2711,6 +2711,63 @@ def test_jsondiff_equal_files(self):
         res = self.run_script('jsondiff', src, dst)
         self.assertEqual((res.returncode, res.stdout), (0, ''), res.stderr)
 
+    def test_jsondiff_closes_inputs(self):
+        for target in (1, 2):
+            with self.subTest(target=target):
+                src = self.write('a.json', {'a': 1})
+                dst = self.write('b.json', {'a': target})
+                parser = jsonpatch_cli.jsondiff_parser
+                args = parser.parse_args([src, dst])
+                self.addCleanup(args.FILE1.close)
+                self.addCleanup(args.FILE2.close)
+                output = io.StringIO()
+                with mock.patch.object(parser, 'parse_args', return_value=args), \
+                        contextlib.redirect_stdout(output):
+                    if target == 1:
+                        jsonpatch_cli.diff_files()
+                        self.assertEqual(output.getvalue(), '')
+                    else:
+                        with self.assertRaises(SystemExit) as caught:
+                            jsonpatch_cli.diff_files()
+                        self.assertEqual(caught.exception.code, 1)
+                        self.assertEqual(jsonpatch.apply_patch({'a': 1}, json.loads(output.getvalue())),
+                                         {'a': target})
+                self.assertTrue(args.FILE1.closed)
+                self.assertTrue(args.FILE2.closed)
+
+    def test_jsondiff_closes_both_inputs_after_parse_error(self):
+        for invalid in (0, 1):
+            with self.subTest(invalid=invalid):
+                paths = [self.write('a.json', {}), self.write('b.json', {})]
+                with open(paths[invalid], 'w', encoding='utf-8') as f:
+                    f.write('{')
+                parser = jsonpatch_cli.jsondiff_parser
+                args = parser.parse_args(paths)
+                self.addCleanup(args.FILE1.close)
+                self.addCleanup(args.FILE2.close)
+                with mock.patch.object(parser, 'parse_args', return_value=args):
+                    with self.assertRaises(json.JSONDecodeError):
+                        jsonpatch_cli.diff_files()
+                self.assertTrue(args.FILE1.closed)
+                self.assertTrue(args.FILE2.closed)
+
+    def test_jsondiff_keeps_stdin_open(self):
+        for stdin_first in (False, True):
+            with self.subTest(stdin_first=stdin_first):
+                path = self.write('a.json', {'a': 1})
+                stdin = io.StringIO('{"a": 1}')
+                self.addCleanup(stdin.close)
+                parser = jsonpatch_cli.jsondiff_parser
+                with mock.patch.object(sys, 'stdin', stdin):
+                    args = parser.parse_args(['-', path] if stdin_first else [path, '-'])
+                    owned = args.FILE2 if stdin_first else args.FILE1
+                    self.addCleanup(owned.close)
+                    with mock.patch.object(parser, 'parse_args', return_value=args), \
+                            contextlib.redirect_stdout(io.StringIO()):
+                        jsonpatch_cli.diff_files()
+                self.assertFalse(stdin.closed)
+                self.assertTrue(owned.closed)
+
     def test_jsondiff_indent(self):
         src = self.write('a.json', {'a': 1})
         dst = self.write('b.json', {'b': 1})