| # fast-json-stable-stringify |
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| Deterministic `JSON.stringify()` - a faster version of [@substack](https://github.com/substack)'s json-stable-strigify without [jsonify](https://github.com/substack/jsonify). |
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| You can also pass in a custom comparison function. |
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| [![Build Status](https://travis-ci.org/epoberezkin/fast-json-stable-stringify.svg?branch=master)](https://travis-ci.org/epoberezkin/fast-json-stable-stringify) |
| [![Coverage Status](https://coveralls.io/repos/github/epoberezkin/fast-json-stable-stringify/badge.svg?branch=master)](https://coveralls.io/github/epoberezkin/fast-json-stable-stringify?branch=master) |
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| # example |
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| ``` js |
| var stringify = require('fast-json-stable-stringify'); |
| var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 }; |
| console.log(stringify(obj)); |
| ``` |
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| output: |
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| ``` |
| {"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8} |
| ``` |
| |
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| # methods |
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| ``` js |
| var stringify = require('fast-json-stable-stringify') |
| ``` |
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| ## var str = stringify(obj, opts) |
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| Return a deterministic stringified string `str` from the object `obj`. |
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| ## options |
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| ### cmp |
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| If `opts` is given, you can supply an `opts.cmp` to have a custom comparison |
| function for object keys. Your function `opts.cmp` is called with these |
| parameters: |
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| ``` js |
| opts.cmp({ key: akey, value: avalue }, { key: bkey, value: bvalue }) |
| ``` |
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| For example, to sort on the object key names in reverse order you could write: |
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| ``` js |
| var stringify = require('fast-json-stable-stringify'); |
| |
| var obj = { c: 8, b: [{z:6,y:5,x:4},7], a: 3 }; |
| var s = stringify(obj, function (a, b) { |
| return a.key < b.key ? 1 : -1; |
| }); |
| console.log(s); |
| ``` |
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| which results in the output string: |
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| ``` |
| {"c":8,"b":[{"z":6,"y":5,"x":4},7],"a":3} |
| ``` |
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| Or if you wanted to sort on the object values in reverse order, you could write: |
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| ``` |
| var stringify = require('fast-json-stable-stringify'); |
| |
| var obj = { d: 6, c: 5, b: [{z:3,y:2,x:1},9], a: 10 }; |
| var s = stringify(obj, function (a, b) { |
| return a.value < b.value ? 1 : -1; |
| }); |
| console.log(s); |
| ``` |
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| which outputs: |
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| ``` |
| {"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10} |
| ``` |
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| ### cycles |
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| Pass `true` in `opts.cycles` to stringify circular property as `__cycle__` - the result will not be a valid JSON string in this case. |
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| TypeError will be thrown in case of circular object without this option. |
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| # install |
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| With [npm](https://npmjs.org) do: |
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| ``` |
| npm install fast-json-stable-stringify |
| ``` |
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| # benchmark |
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| To run benchmark (requires Node.js 6+): |
| ``` |
| node benchmark |
| ``` |
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| Results: |
| ``` |
| fast-json-stable-stringify x 17,189 ops/sec ±1.43% (83 runs sampled) |
| json-stable-stringify x 13,634 ops/sec ±1.39% (85 runs sampled) |
| fast-stable-stringify x 20,212 ops/sec ±1.20% (84 runs sampled) |
| faster-stable-stringify x 15,549 ops/sec ±1.12% (84 runs sampled) |
| The fastest is fast-stable-stringify |
| ``` |
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| # license |
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| [MIT](https://github.com/epoberezkin/fast-json-stable-stringify/blob/master/LICENSE) |