What is the difference between Webpack-merge and Object.assign()?

Question

I'm working with webpack and finally I can't see the opportunity of this package since it seems Object.assign make the job, but maybe there is something between the lines about this package ?

Thanks

Answer 1

The difference between "webpack-merge" npm package and Object.assign() (or object spread) is how they handle property with the same name:

const webpackMerge = require("webpack-merge");

const object1 = {
  'x': [{'a': 'a' }, { 'b': 'b' }]
}

const object2 = {
  'x': [{'c': 'c' }, { 'd': 'd' }]
}

console.log('result webpackMerge: ',
  webpackMerge(object1, object2)
)

console.log('result Object.assign: ',
  Object.assign({}, object1, object2)
)

console.log('result Object.spread: ',
  {...object1, ...object2}
)

The above will give you:

result webpackMerge:  { x: [ { a: 'a' }, { b: 'b' }, { c: 'c' }, { d: 'd' } ] }
result Object.assign:  { x: [ { c: 'c' }, { d: 'd' } ] }
result Object spread:  { x: [ { c: 'c' }, { d: 'd' } ] }

As you can see above Object.assign() (or Object spread) overwrite the value of previous properties with the latter one, while webpack-merge concat the element of the array.

see above code in Runkit