collection-deep-merge
v1.3.0
Published
Deep merge array of objects by passed key. Objects with same key vals will merge together
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collection-deep-merge
Genereal purpose arrays of objects by key merger.
Ready for browsers (const
, let
compatible) and node.js v4+.
IE11+, FF36+, Safari5.1+, Android
Works well as redux store helper.
Extensible via custom merger and comparator (Dependency Injection factory). Look more below.
It does not mutate arguments, it returns a new collection (Immutability).
usage
Open test.js with examples
const mergeById = mergeCollectionsBy('id')
//
// Deep merge object-items
const list1 = [ { a: 1, b: { c: 1 } }, { a: 2, b: { d: 2 } } ];
const list2 = [ { a: 1, b: { c: 3 } }, { a: 2, b: { c: 4 } } ];
const merged = [ { a: 1, b: { c: 3 } }, { a: 2, b: { c: 4, d: 2 } } ];
mergeById(list, [ item ]) ==== merged // deep equal
//
// Merge item with a collection
const list = [ { a: 1, b: 2 }, { a: 2, d: 4 } ];
const item = { a: 1, c: 3 };
const merged = [{ a: 1, b: 2, c: 3 }, { a: 2, d: 4 }]
mergeById(list, [ item ]) ==== merged // deep equal
tips & tricks
Custom item[key]
s comparators and item
s mergers
const mergeCollectionsBy = require('collection-deep-merge');
const is = (a, b) => a !== undefined && a === b;
// You can merge in a shallow manner
// or implement very custom strategy
const merge = (a, b) => {/* custom merger */};
const mergeDeepById = mergeCollectionsBy('id', { is, merge });
Shallow merge
import mergeCollectionsBy, { mergeShallow } = 'collection-deep-merge';
const mergeShallowById = mergeCollectionsBy('id', { merge: mergeShallow });
Nested collections
You can implement custom merger based on
const { mergeDeep } = require('collection-deep-merge')
with an especial behaviour on nested collections.
You should support followed api:
- merger is immutable
- merger invokes with
(Object a, Object b)
args - merger returns
Object c
Alternatives
array-join
collection-deep-merge like its fullJoin
with deep item-objects merge
Map from ES6
New native Map has all you need:
- preserve order
- O(1) access
- iterable
You can implement tiny union function (w/o deep items merging):
function union(map1, map2) {
return new Map([...map1, ...map2]);
}
or you can use the collection-deep-merge if you want to merge items deeply
O(n*m) + O(?)
complexity (n*m
not so good; ?
stands for deep merge).
import mergeArrays from 'collection-deep-merge';
const mergeById = mergeArrays('id', { eq: (item1, item2) => {} });
const mergeMapsById = (map1, map2) => {
mergeById([...map1], [...map2])
};
or ... // todo: create map-deep-union
library special for Maps with O(n)+O(?)
complexity.