`qmk format-json`: Add an in-place mode to format json command (#21610)

lib/python/qmk/cli/format/json.py

@@ -15,6 +15,8 @@ from qmk.path import normpath
 
 @cli.argument('json_file', arg_only=True, type=normpath, help='JSON file to format')
 @cli.argument('-f', '--format', choices=['auto', 'keyboard', 'keymap'], default='auto', arg_only=True, help='JSON formatter to use (Default: autodetect)')
+@cli.argument('-i', '--inplace', action='store_true', arg_only=True, help='If set, will operate in-place on the input file')
+@cli.argument('-p', '--print', action='store_true', arg_only=True, help='If set, will print the formatted json to stdout ')
 @cli.subcommand('Generate an info.json file for a keyboard.', hidden=False if cli.config.user.developer else True)
 def format_json(cli):
     """Format a json file.
@@ -61,5 +63,14 @@ def format_json(cli):
 
                 json_file['layers'][layer_num] = current_layer
 
-    # Display the results
-    print(json.dumps(json_file, cls=json_encoder, sort_keys=True))
+    output = json.dumps(json_file, cls=json_encoder, sort_keys=True)
+
+    if cli.args.inplace:
+        with open(cli.args.json_file, 'w+', encoding='utf-8') as outfile:
+            outfile.write(output)
+
+    # Display the results if print was set
+    # We don't operate in-place by default, so also display to stdout
+    # if in-place is not set.
+    if cli.args.print or not cli.args.inplace:
+        print(output)