json-stringify-deterministic

    1.0.1 • Public • Published

    json-stringify-deterministic

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    Deterministic version of JSON.stringify(), so you can get a consistent hash from stringified results.

    Similar to json-stable-stringify but:

    • No Dependencies. Minimal as possible.
    • Better cycles detection.
    • Support serialization for object without .toJSON (such as RegExp).

    Install

    $ npm install json-stringify-deterministic --save

    Usage

    const stringify = require('json-stringify-deterministic')
    const obj = { c: 8, b: [{z: 6, y: 5, x: 4}, 7], a: 3 }
     
    console.log(stringify(obj))
    // => {"c":8,"b":[{"y":5,"x":4,"z":6},7],"a":3}

    ProTip: You can use it with sort-keys-recursive:

    const stringify = require('json-stringify-deterministic')
    const sortKeysRecursive = require('sort-keys-recursive')
     
    const obj = { c: 8, b: [{z: 6, y: 5, x: 4}, 7], a: 3 }
     
    console.log(stringify(sortKeysRecursive(obj)))
    // => {"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8}

    API

    stringify(<obj>, [opts])

    obj

    Required
    Type: object

    The input object to be serialized.

    opts

    opts.stringify

    Type: function Default: JSON.stringify

    Determinate how to stringify primitives values.

    opts.cycles

    Type: boolean Default: false

    Determinate how to resolve cycles.

    Under false, when a cycle is detected, [Circular] will be inserted in the node.

    opts.compare

    Type: function

    Custom comparison function for object keys.

    Your function opts.compare is called with these parameters:

    opts.cmp({ key: akey, value: avalue }, { key: bkey, value: bvalue })

    For example, to sort on the object key names in reverse order you could write:

    const stringify = require('json-stringify-deterministic')
     
    const obj = { c: 8, b: [{z: 6,y: 5,x: 4}, 7], a: 3 }
    const objSerializer = stringify(obj, function (a, b) {
      return a.key < b.key ? 1 : -1
    })
     
    console.log(objSerializer)
    // => {"c":8,"b":[{"z":6,"y":5,"x":4},7],"a":3}

    Or if you wanted to sort on the object values in reverse order, you could write:

    const stringify = require('json-stringify-deterministic')
     
    const obj = { d: 6, c: 5, b: [{z: 3, y: 2, x: 1}, 9], a: 10 }
    const objtSerializer = stringify(obj, function (a, b) {
      return a.value < b.value ? 1 : -1
    })
     
    console.log(objtSerializer)
    // => {"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10}
    opts.space

    Type: string
    Default: ''

    If you specify opts.space, it will indent the output for pretty-printing.

    Valid values are strings (e.g. {space: \t}). For example:

    const stringify = require('json-stringify-deterministic')
     
    const obj = { b: 1, a: { foo: 'bar', and: [1, 2, 3] } }
    const objSerializer = stringify(obj, { space: '  ' })
    console.log(objSerializer)
    // => {
    //   "a": {
    //     "and": [
    //       1,
    //       2,
    //       3
    //     ],
    //     "foo": "bar"
    //   },
    //   "b": 1
    // }
    opts.replacer

    Type: function

    The replacer parameter is a function opts.replacer(key, value) that behaves the same as the replacer from the core JSON object.

    License

    MIT © Kiko Beats.

    Install

    npm i json-stringify-deterministic

    DownloadsWeekly Downloads

    17,825

    Version

    1.0.1

    License

    MIT

    Last publish

    Collaborators

    • kikobeats