132 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
			
		
		
	
	
			132 lines
		
	
	
		
			3.4 KiB
		
	
	
	
		
			Markdown
		
	
	
	
	
	
# fast-json-stable-stringify
 | 
						|
 | 
						|
Deterministic `JSON.stringify()` - a faster version of [@substack](https://github.com/substack)'s json-stable-strigify without [jsonify](https://github.com/substack/jsonify).
 | 
						|
 | 
						|
You can also pass in a custom comparison function.
 | 
						|
 | 
						|
[](https://travis-ci.org/epoberezkin/fast-json-stable-stringify)
 | 
						|
[](https://coveralls.io/github/epoberezkin/fast-json-stable-stringify?branch=master)
 | 
						|
 | 
						|
# example
 | 
						|
 | 
						|
``` 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));
 | 
						|
```
 | 
						|
 | 
						|
output:
 | 
						|
 | 
						|
```
 | 
						|
{"a":3,"b":[{"x":4,"y":5,"z":6},7],"c":8}
 | 
						|
```
 | 
						|
 | 
						|
 | 
						|
# methods
 | 
						|
 | 
						|
``` js
 | 
						|
var stringify = require('fast-json-stable-stringify')
 | 
						|
```
 | 
						|
 | 
						|
## var str = stringify(obj, opts)
 | 
						|
 | 
						|
Return a deterministic stringified string `str` from the object `obj`.
 | 
						|
 | 
						|
 | 
						|
## options
 | 
						|
 | 
						|
### cmp
 | 
						|
 | 
						|
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:
 | 
						|
 | 
						|
``` js
 | 
						|
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:
 | 
						|
 | 
						|
``` 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);
 | 
						|
```
 | 
						|
 | 
						|
which results in the output string:
 | 
						|
 | 
						|
```
 | 
						|
{"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:
 | 
						|
 | 
						|
```
 | 
						|
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);
 | 
						|
```
 | 
						|
 | 
						|
which outputs:
 | 
						|
 | 
						|
```
 | 
						|
{"d":6,"c":5,"b":[{"z":3,"y":2,"x":1},9],"a":10}
 | 
						|
```
 | 
						|
 | 
						|
### cycles
 | 
						|
 | 
						|
Pass `true` in `opts.cycles` to stringify circular property as `__cycle__` - the result will not be a valid JSON string in this case.
 | 
						|
 | 
						|
TypeError will be thrown in case of circular object without this option.
 | 
						|
 | 
						|
 | 
						|
# install
 | 
						|
 | 
						|
With [npm](https://npmjs.org) do:
 | 
						|
 | 
						|
```
 | 
						|
npm install fast-json-stable-stringify
 | 
						|
```
 | 
						|
 | 
						|
 | 
						|
# benchmark
 | 
						|
 | 
						|
To run benchmark (requires Node.js 6+):
 | 
						|
```
 | 
						|
node benchmark
 | 
						|
```
 | 
						|
 | 
						|
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
 | 
						|
```
 | 
						|
 | 
						|
 | 
						|
## Enterprise support
 | 
						|
 | 
						|
fast-json-stable-stringify package is a part of [Tidelift enterprise subscription](https://tidelift.com/subscription/pkg/npm-fast-json-stable-stringify?utm_source=npm-fast-json-stable-stringify&utm_medium=referral&utm_campaign=enterprise&utm_term=repo) - it provides a centralised commercial support to open-source software users, in addition to the support provided by software maintainers.
 | 
						|
 | 
						|
 | 
						|
## Security contact
 | 
						|
 | 
						|
To report a security vulnerability, please use the
 | 
						|
[Tidelift security contact](https://tidelift.com/security).
 | 
						|
Tidelift will coordinate the fix and disclosure. Please do NOT report security vulnerability via GitHub issues.
 | 
						|
 | 
						|
 | 
						|
# license
 | 
						|
 | 
						|
[MIT](https://github.com/epoberezkin/fast-json-stable-stringify/blob/master/LICENSE)
 |