fixjson

Install the fixjson command globally using npm to use it as a CLI tool.

$ npm install -g fixjson

The fixjson CLI reads input in relaxed JSON5 format and outputs valid, pretty-printed JSON.

• If you provide file paths (including globs like dir/**/*.json), it processes those files.
• If you provide a directory, it formats all JSON files within that directory.
• If no path is provided, it reads from STDIN.

Common use cases include fixing trailing commas, adding missing commas, quoting object keys, converting single quotes to double quotes, handling newlines in strings, and converting hex numbers to decimal.

fixjson [--write|--indent|--minify|--stdin-filename] [paths...]

The fixjson CLI is designed to be used with editor extensions for automatic formatting. Supported integrations include:

• Vim: via vim-fixjson, ALE, neoformat, or vim-autoformat.
• Other editors that can call CLI tools for formatting.

The FixJSON class accepts an optional Config object to control how JSON is parsed and written.

Key configuration options:

• write: If true, the tool will overwrite the original files. If false (default), it outputs the fixed JSON to stdout.
• indent: Controls indentation. Can be a number (representing the number of spaces) or left undefined to use automatic detection via detect-indent.
• minify: If true, the output will be minified (no indentation).
• stdinFilename: A string used as the filename label when reading from stdin.
• stdout: A NodeJS.WriteStream to redirect the output (defaults to process.stdout).

export interface Config {
    write?: boolean;
    indent?: number;
    minify?: boolean;
    stdinFilename?: string;
    stdout?: NodeJS.WriteStream;
}

The following flags are available for the fixjson command:

• --write or -w: Overwrites the input files with the fixed JSON.
• --indent {num} or -i {num}: Sets the indentation width. If this option is not provided, the tool automatically detects the indentation spaces.
• --minify: Minifies the output JSON.
• --stdin-filename: Used when reading from STDIN to specify the filename (useful for tools that rely on file extensions).
• [paths...]: One or more file paths or globs to process.

# Example: Overwrite files with detected indentation
fixjson --write file.json

# Example: Use a specific indentation width
fixjson --indent 2 file.json

# Example: Process all JSON files in a directory using a glob
fixjson "dir/**/*.json"

The fixFile helper function provides a shorthand way to read a file, fix its JSON content, and return the result as a string. This is an asynchronous operation.

import { fixFile } from './index';

async function run() {
  const fixedContent = await fixFile('config.json', { indent: 2 });
  console.log(fixedContent);
}
run();

The fixString helper function provides a shorthand way to fix a JSON string without manually instantiating the FixJSON class. It returns the formatted JSON string.

import { fixString } from './index';

const input = '{ name: "rhysd" }';
const output = fixString(input, { indent: 4 });
console.log(output);

The following options are available for the fixjson command line interface:

-w, --write          Overwrite a file instead of outputting to stdout (boolean, default: false)
--minify             Disable pretty print (boolean, default: false)
-i, --indent         Indent of JSON output (number, default: undefined)
--stdin-filename     Assuming a file name when reading from stdin (string, default: undefined)