UMD bundle is 567B minified+gzipped
Merge the enumerable attributes of two objects deeply.
Check out the changes from version 1.x to 2.0.0
For the old array element-merging algorithm, see the arrayMerge option below.
If you have require('deepmerge') (as opposed to import merge from 'deepmerge') anywhere in your codebase, Webpack 3 and 4 have a bug that breaks bundling.
If you see Error: merge is not a function, add this alias to your Webpack config:
alias: {
deepmerge$: path.resolve(__dirname, 'node_modules/deepmerge/dist/umd.js'),
}
var x = {
foo: { bar: 3 },
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: 3,
baz: 4
},
array: [{
does: 'work',
too: [ 1, 2, 3 ]
}, {
does: 'work',
too: [ 4, 5, 6 ]
}, {
really: 'yes'
}],
quux: 5
}
merge(x, y) // => expectedvar merge = require('deepmerge')
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.
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]) // => expectedThe 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.
The options object will include the default isMergeableObject implementation if the top-level consumer didn't pass a custom function in.
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 emptyTarget = value => Array.isArray(value) ? [] : {}
const clone = (value, options) => merge(emptyTarget(value), value, options)
function oldArrayMerge(target, source, options) {
const destination = target.slice()
source.forEach(function(e, i) {
if (typeof destination[i] === 'undefined') {
const cloneRequested = options.clone !== false
const shouldClone = cloneRequested && options.isMergeableObject(e)
destination[i] = shouldClone ? clone(e, options) : e
} else if (options.isMergeableObject(e)) {
destination[i] = merge(target[i], e, options)
} 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']By default, deepmerge clones every property from almost every kind of object.
You may not want this, if your objects are of special types, and you want to copy the whole object instead of just copying its properties.
You can accomplish this by passing in a function for the isMergeableObject option.
If you only want to clone properties of plain objects, and ignore all "special" kinds of instantiated objects, you probably want to drop in is-plain-object.
const isPlainObject = require('is-plain-object')
function SuperSpecial() {
this.special = 'oh yeah man totally'
}
const instantiatedSpecialObject = new SuperSpecial()
const target = {
someProperty: {
cool: 'oh for sure'
}
}
const source = {
someProperty: instantiatedSpecialObject
}
const defaultOutput = merge(target, source)
defaultOutput.someProperty.cool // => 'oh for sure'
defaultOutput.someProperty.special // => 'oh yeah man totally'
defaultOutput.someProperty instanceof SuperSpecial // => false
const customMergeOutput = merge(target, source, {
isMergeableObject: isPlainObject
})
customMergeOutput.someProperty.cool // => undefined
customMergeOutput.someProperty.special // => 'oh yeah man totally'
customMergeOutput.someProperty instanceof SuperSpecial // => trueDeprecated.
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.
With npm do:
npm install deepmergeJust want to download the file without using any package managers/bundlers? Download the UMD version from unpkg.com.
With npm do:
npm testMIT
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