objectSimilarity.js

const generateHash = require('object-hash')
const randomColor = require('randomcolor')

const similarity = {}

const uniqRandomColor = (options = {}) => {
  let color = randomColor(options)
  while (Object.values(similarity).includes(color)) {
    color = randomColor(options)
  }

  return color
}

const objectSimilarity = (objects = [], options = {}) => {
  return objects.map((object) => {
    const hash = generateHash(object)

    const color = similarity[hash]
      ? similarity[hash]
      : (similarity[hash] = uniqRandomColor(options))

    return { object, color, hash }
  })
}

export { objectSimilarity }



describe('uniqRandomColor', () => {
  it('similarity', () => {
    const data = objectSimilarity([{ foo: 1 }, { foo: 1 }, { bar: 1 }])
    const colors = {}
    data.map((e) => {
      colors[e.hash] ||= []
      colors[e.hash].push(e.color)
    })

    Object.entries(colors).map(([hash, colors]) => {
      const uniq = [...new Set(colors)]
      expect(uniq.length).to.be.equal(1)
    })
  })
})