json-format

# JSON Formatter Format and validate JSON — pretty-print with configurable indentation or minify to a single line. ## Input - A JSON string (object, array, string, number, boolean, or null) - May be already formatted or a single minified line - Optional action: format (default), minify, or validate-only - Optional indent size: 2 (default) or 4 spaces ## Output - **format**: Pretty-printed JSON with proper indentation and line breaks - **minify**: Single-line compact JSON with no whitespace - **validate**: A message confirming valid or invalid JSON (with error details) ## Instructions 1. Receive the raw JSON string from the user. 2. Determine the requested action (default: format). 3. Attempt to parse the JSON: - Call `JSON.parse(input)` conceptually — parse the string strictly following JSON spec. - If parsing fails, report the error with as much detail as possible (e.g., "Unexpected token at position 42", "Missing closing bracket"). 4. For **format** action: - Serialize the parsed value back to a string with the requested indent size (default: 2 spaces). - Use `JSON.stringify(parsed, null, indentSize)` semantics: keys are sorted by insertion order (not alphabetically), arrays and objects are expanded across multiple lines, strings are double-quoted. 5. For **minify** action: - Serialize with no indentation or extra whitespace: `JSON.stringify(parsed)` semantics. 6. For **validate** action: - If parsing succeeded, report "Valid JSON" along with type and top-level key count if it is an object. - If parsing failed, report the error message. 7. If sort-keys option is requested, sort all object keys alphabetically at every nesting level before serializing. 8. Output the result. ## Options - `indent`: `2` (default) | `4` — number of spaces per indent level - `action`: `format` (default) | `minify` | `validate` - `sort-keys`: `false` (default) | `true` — sort object keys alphabetically ## Examples **Format (default, 2-space indent)** Input: ``` {"name":"Alice","age":30,"hobbies":["reading","coding"]} ``` Output: ```json { "name": "Alice", "age": 30, "hobbies": [ "reading", "coding" ] } ``` **Minify** Input: ```json { "name": "Alice", "age": 30 } ``` Output: ``` {"name":"Alice","age":30} ``` **Validate — invalid JSON** Input: ``` {name: 'Alice', age: 30} ``` Output: ``` Invalid JSON: Unexpected token 'n' at position 1. Keys must be double-quoted strings and string values must use double quotes, not single quotes. ``` **Format with 4-space indent and sort-keys** Input: ``` {"z":3,"a":1,"m":2} ``` Output: ```json { "a": 1, "m": 2, "z": 3 } ``` ## Error Handling - If the input is empty or whitespace-only, respond: "No input provided. Please paste a JSON string." - If `JSON.parse` fails, report the error message and the approximate position or line number if determinable. Do not attempt to silently fix the JSON — report the exact parse error. (If the user wants repair, suggest using the json-repair skill.) - If the input is valid JSON but the user asked to "format" a primitive (e.g., just `42` or `"hello"`), format it as-is (a primitive is valid JSON). - Never truncate the output — always return the full formatted result.