Object literals: Compared values have no visual difference.

System:
    OS: Windows 10
    CPU: x64 Intel(R) Core(TM) i7-4790K CPU @ 4.00GHz
Binaries:
    npm: 5.8.0 - C:\Users\Owner\AppData\Roaming\npm\npm.CMD

I am on jest@22.4.3.

The two objects are the same. I’ve done some research, and it seems that the Compared values have no visual difference. occurs when there is an anonymous function in question. This is not the case.

Here’s the code:

const stripData = obj => obj.data
const assign = child => parent => Object.assign(parent, child)
const arrAssign = (arr, k) => data => data.map((d, i) => assign({[k]: d})(arr[i]))

/* function being tested */
const insertAndPair = (obj, key1, key2) => compose(
  d => assign({ [key1]: arrAssign(obj.slice(-1)[0][key1], key2)(d) })(obj.slice(-1)),
  stripData
)

Here’s the test:

it('given an array and key then an object, assigns the first'
  + ' element in the array to the object with the given key', () => {

    const arr = [{
      vals: [
        { x: [], y: 'hello'},
        { x: [], y: 'hey'}
      ]
    }]

    expect(
      insertAndPair(arr, 'vals', 'x')({data: [1, 2]})
    ).toEqual([ { vals: [
      { x: 1, y: 'hello' },
      { x: 2, y: 'hey' }
    ] } ])
  })

Pardon my convoluted code, haha!

[Kaelinator]

Wrapping them both in JSON.stringify passes the test, but I find this to be a workaround rather than a fix.

[Yorkshireman]

@SimenB how about “Compared values have no visual difference but may have different properties.”