MagicJSON

Parse then re-stringify JSON strings and files, preserving indentation and line endings.

The primary use case is to load/edit/save JSON files like package.json in a lossless-ish way.

Usage

import MagicJSON from 'magic-json'

// Read and parse some JSON object from a file:
const pkg = await MagicJSON.fromFile('./package.json')

// Edit the object at will:
pkg.version = '2.0.0'
delete pkg.private

// Then write it back to the same file,
// with the same indentation and line endings:
await MagicJSON.write(pkg)

API

MagicJSON can be used as a drop-in replacement for the JavaScript JSON API.

MagicJSON.parse<T = any>(text: string, reviver?: (this: any, key: string, value: any) => any): T

• This API has the same signature as JSON.parse(), which it calls under the hood. Once parsed, the source text is analyzed to determine the indentation and line endings. This information is then stored in an internal WeakMap.

MagicJSON.stringify(value: any, replacer?: (this: any, key: string, value: any) => any, space?: string | number): string

• This API has the same signature as JSON.stringify(), which it calls under the hood. It uses the information stored by .parse() to revive the text with the same indentation (unless the space parameter is given) and line endings.

Notes

• MagicJSON.stringify() works the same as JSON.stringify() if value is not a MagicJSON object.
• If value is a MagicJSON object and space is given, it overrides the detected indentation.

async MagicJSON.fromFile<T = any>(filepath: string): Promise<T>

• Reads some JSON text from a file and calls .parse() on it.

async MagicJSON.write(value: any, filepath?: string): Promise<void>

• Calls .stringify() and writes the result back to the same file the JSON text was loaded from, unless a different filepath is given.

Notes

• If filepath is given, it overrides the path associated with the object.
• filepath is mandatory if either value is not a MagicJSON object or it wasn't loaded with .fromFile().

MagicJSON.isMagic(value: any): boolean

• Returns true if value is a MagicJSON object, false otherwise.

MagicJSON.isManaged(value: any): boolean

• Deprecated. Use MagicJSON.isMagic(value) instead.

Changelog

See releases.

License

MIT