Parse-json-path NPM

✂️ parse-json-path

Slice a string at characters `.` - `[` - and `]` - but not '\\.'

Features

Handles '.' in key name by prepending a '\\' to it.
- For example keyFoo.keyBar.key\\.Baz
Returns fully numeric keys as integer values representing an array index.
Handles numeric and escaped-dot tokens at combination within key names.

Motivation

In a whole handful of minutes I didn't come across something that did the specific thing. Also, I think having type declarations is pretty handy, even for projects not utilizing typescript, so I became the change I wanted to see in the world. 🌈

About

A majority of the module is a RegExp pattern:

/((.\\\.|[^[\].])*).(?=\.|\n|\r|$)/g

The array of matched substrings are then matched against a simpler pattern - /[0-9]+/gu - if there is a singlular match of the whole string, parseInt provides the value of that element. This accounts for puzzing yet possible scenarios where keys of a JSON file are something like --

  {
    "0.0": "value",
    "1.0": "value"
  }

-- which is valid JSON according to the spec.

Install

yarn add parse-json-path
npm i parse-json-path

Module use

CommonJS module

const parseJsonPath = require('parse-json-path')

/* ... */

parseJsonPath(someString)

ES2017

import { parseJsonPath } from 'parse-json-path'

/* ... */

parseJsonPath(someString)

API

parseJsonPath(string, boolean)

Parameter	Type
`path`	`string`
`silentFail`	`undefined \| boolean`

In the case that the value to be parsed is:

Not a string
Without matches against the first regex

The function accepts an optional second argument - silentFail?: boolean. If truthy, the above scenarios result in a return value of undefined, rather than throwing an Error. Results can then be handled as needed.

Sample of inputs the resuturned JSON selectors

>> Test report and samples last generated on 2019-11-23T06:31:34.516Z

parseJsonPath('key1.easy')
//=> [ 'key1', 'easy' ]

parseJsonPath('key1.dot\\.key.1')
//=> [ 'key1', 'dot.key', 1 ]

parseJsonPath('key1.dot\\.key.3.array4key.nested')
//=> [ 'key1', 'dot.key', 3, 'array4key', 'nested' ]

parseJsonPath('0\\.sneakyKey')
//=> [ '0.sneakyKey' ]

parseJsonPath('0.0\\.sneakyKey')
//=> [ 0, '0.sneakyKey' ]

Test Output

  √ Parse key path: key1.easy
  √ Parse key path: key1.dot\.key.1
  √ Parse key path: key1.dot\.key.3.array4key.nested
  √ Parse key path: 0\.sneakyKey
  √ Parse key path: 0.0\.sneakyKey

  5 tests passed