deep6

deep6 is a no-dependency ES6 mini-library:

• Advanced deep equivalency for JavaScript structures.
  • Extensible to accommodate custom objects.
• Traversing objects.
  • Extensible deep cloning.
• Written in ES6:
  • Use it in Node or browsers without transpiling.
  • Natively supports Map, Set, typed arrays.
  • Natively supports symbols and property descriptors.
  • Presented as ES6 modules, yet provides CommonJS modules for convenience.
• Efficient non-recursive algorithms.
  • ~500 tests to ensure correctness.
  • Support for circular dependencies.
  • Support for "loose" comparisons.
• Unification.
  • Identifying and capturing object fragments.

Intro

import equal, {match, clone, any} from 'deep6';

const x = {a: 1, b: 2, c: ['hi!', 42, null, {}]};

// deep equality
equal(x, {b: 2, a: 1, c: ['hi!', 42, null, {}]});     // true
equal(x, {b: 2, a: 1, c: ['hi!', 42, null, {z: 1}]}); // false

// pattern matching
match(x, {a: 1});         // true
match(x, {z: 1});         // false
match(x, {a: 1, c: any}); // true
match(x, {a: 1, c: []});  // false
match(x, {a: 1, d: any}); // false

// deep cloning
const y = clone(x);
equal(x, y);              // true

// circular dependencies are fine
const z = {},
  w = {};
z.z = z;
w.z = w;
const p = clone(w);
equal(z, w);              // true
equal(z, p);              // true

// more standard types
const m = {a: new Map(), b: Buffer.from([99, 98, 97])};
m.a.set('a', [Symbol(), new Set([1, 2, 3])]);
m.a.set('b', [/^abc/i, new Date()]);
const n = clone(m);
equal(m, n);              // true

// advanced: symbols
const s = Symbol(),
  t = {[s]: 42, [Symbol.for('deep6')]: 33},
  u = {[s]: 42, [Symbol.for('deep6')]: 33},
  v = clone(u, {symbols: true});
equal(t, u, {symbols: true}); // true
equal(t, v, {symbols: true}); // true

// advanced: clone non-enumerable properties
const r = {a: 1};
Object.defineProperty(r, 'b', {value: 2, enumerable: false});
const q = clone(r, {allProps: true});
r === q;                  // false
equal(r, {a: 1});         // true
equal(r, {a: 1, b: 2});   // false
r.a === q.a;              // true
r.b === q.b;              // true

Docs

All pertinent information is in the wiki.

Installation and use

npm install --save deep6

// ES6 modules
import equal, {clone} from 'deep6';
import matchString from 'deep6/unifiers/matchString';

// CommonJS modules
const {equal, clone} = require('deep6/cjs');
const matchString = require('deep6/cjs/unifiers/matchString').default;

Release History

• 1.1.3 updated dev deps.
• 1.1.2 updated dev deps.
• 1.1.1 reformulated any as a well-known symbol.
• 1.1.0 separated from yopl, extensive refactoring.
• 1.0.1 added the exports statement.
• 1.0.0 the first 1.0 release.