json-stringify-deterministic

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

Similar to json-stable-stringifybut:

• 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

conststringify=require('json-stringify-deterministic')constobj={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:

conststringify=require('json-stringify-deterministic')constsortKeysRecursive=require('sort-keys-recursive')constobj={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:

conststringify=require('json-stringify-deterministic')constobj={c: 8,b: [{z: 6,y: 5,x: 4},7],a: 3}constobjSerializer=stringify(obj,function(a,b){returna.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:

conststringify=require('json-stringify-deterministic')constobj={d: 6,c: 5,b: [{z: 3,y: 2,x: 1},9],a: 10}constobjtSerializer=stringify(obj,function(a,b){returna.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:

conststringify=require('json-stringify-deterministic')constobj={b: 1,a: {foo: 'bar',and: [1,2,3]}}constobjSerializer=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.