odin-javascript-exercises/node_modules/fast-json-stable-stringify/index.js
2017-12-15 12:56:14 -06:00

59 lines
1.8 KiB
JavaScript

'use strict';
module.exports = function (data, opts) {
if (!opts) opts = {};
if (typeof opts === 'function') opts = { cmp: opts };
var cycles = (typeof opts.cycles === 'boolean') ? opts.cycles : false;
var cmp = opts.cmp && (function (f) {
return function (node) {
return function (a, b) {
var aobj = { key: a, value: node[a] };
var bobj = { key: b, value: node[b] };
return f(aobj, bobj);
};
};
})(opts.cmp);
var seen = [];
return (function stringify (node) {
if (node && node.toJSON && typeof node.toJSON === 'function') {
node = node.toJSON();
}
if (node === undefined) return;
if (typeof node == 'number') return isFinite(node) ? '' + node : 'null';
if (typeof node !== 'object') return JSON.stringify(node);
var i, out;
if (Array.isArray(node)) {
out = '[';
for (i = 0; i < node.length; i++) {
if (i) out += ',';
out += stringify(node[i]) || 'null';
}
return out + ']';
}
if (node === null) return 'null';
if (seen.indexOf(node) !== -1) {
if (cycles) return JSON.stringify('__cycle__');
throw new TypeError('Converting circular structure to JSON');
}
var seenIndex = seen.push(node) - 1;
var keys = Object.keys(node).sort(cmp && cmp(node));
out = '';
for (i = 0; i < keys.length; i++) {
var key = keys[i];
var value = stringify(node[key]);
if (!value) continue;
if (out) out += ',';
out += JSON.stringify(key) + ':' + value;
}
seen.splice(seenIndex, 1);
return '{' + out + '}';
})(data);
};