deepmerge-plus
v3.0.2
Published
A library for deep (recursive) merging of Javascript objects
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deepmerge-plus
Merge the enumerable attributes of two objects deeply.
npm install deepmerge-plus
Check out the changes from version 1.x to 2.0.0
For the old array element-merging algorithm, see the arrayMerge
option below.
example
var moment = require('moment')
var monday = moment('2016-09-27T01:08:12.761Z')
var tuesday = moment('2016-09-28T01:18:12.761Z')
var target = {
date: monday
}
var source = {
date: tuesday
}
let options = {
isMergeableObject(value, isMergeableObject) {
let bool;
if (bool = moment.isMoment(value)) {
return false;
}
return isMergeableObject(value)
}
}
var expected = {
date: tuesday
}
var actual = merge(target, source, options) // => expected
var x = {
foo: { bar: 5 },
array: [{
does: 'work',
too: [ 1, 2, 3 ]
}]
}
var y = {
foo: { baz: 4 },
quux: 5,
array: [{
does: 'work',
too: [ 4, 5, 6 ]
}, {
really: 'yes'
}]
}
var expected = {
foo: {
bar: 5,
baz: 4
},
array: [{
does: 'work',
too: [ 1, 2, 3 ]
}, {
does: 'work',
too: [ 4, 5, 6 ]
}, {
really: 'yes'
}],
quux: 5
}
merge(x, y) // => expected
methods
var merge = require('deepmerge')
merge(x, y, [options])
Merge two objects x
and y
deeply, returning a new merged object with the
elements from both x
and y
.
If an element at the same key is present for both x
and y
, the value from
y
will appear in the result.
Merging creates a new object, so that neither x
or y
are be modified.
merge.all(arrayOfObjects, [options])
Merges any number of objects into a single result object.
var x = { foo: { bar: 3 } }
var y = { foo: { baz: 4 } }
var z = { bar: 'yay!' }
var expected = { foo: { bar: 3, baz: 4 }, bar: 'yay!' }
merge.all([x, y, z]) // => expected
options
arrayMerge
The merge will also concatenate arrays and merge array values by default.
However, there are nigh-infinite valid ways to merge arrays, and you may want to supply your own. You can do this by passing an arrayMerge
function as an option.
function overwriteMerge(destinationArray, sourceArray, options) {
return sourceArray
}
merge(
[1, 2, 3],
[3, 2, 1],
{ arrayMerge: overwriteMerge }
) // => [3, 2, 1]
To prevent arrays from being merged:
const dontMerge = (destination, source) => source
const output = merge({ coolThing: [1,2,3] }, { coolThing: ['a', 'b', 'c'] }, { arrayMerge: dontMerge })
output // => { coolThing: ['a', 'b', 'c'] }
To use the old (pre-version-2.0.0) array merging algorithm, pass in this function:
const isMergeableObject = require('is-mergeable-object')
const emptyTarget = value => Array.isArray(value) ? [] : {}
const clone = (value, options) => merge(emptyTarget(value), value, options)
function oldArrayMerge(target, source, optionsArgument) {
const destination = target.slice()
source.forEach(function(e, i) {
if (typeof destination[i] === 'undefined') {
const cloneRequested = !optionsArgument || optionsArgument.clone !== false
const shouldClone = cloneRequested && isMergeableObject(e)
destination[i] = shouldClone ? clone(e, optionsArgument) : e
} else if (isMergeableObject(e)) {
destination[i] = merge(target[i], e, optionsArgument)
} else if (target.indexOf(e) === -1) {
destination.push(e)
}
})
return destination
}
merge(
[{ a: true }],
[{ b: true }, 'ah yup'],
{ arrayMerge: oldArrayMerge }
) // => [{ a: true, b: true }, 'ah yup']
clone
Deprecated.
Defaults to true
.
If clone
is false
then child objects will be copied directly instead of being cloned. This was the default behavior before version 2.x.
install
With npm do:
npm install deepmerge
Just want to download the file without using any package managers/bundlers? Download the UMD version from unpkg.com.
test
With npm do:
npm test
license
MIT