mergeObjectArraysByName.js

const stateFiles = [
  {name: 'john'},
  {name: 'lewis'},
]

const files = [
  {name: 'ana'},
  {name: 'john', email: "john@mail.com"},

]

function mergeObjectArraysByName(prev, next) {
	return prev.reduce((acc, prevItem, i) => {
		const exists = acc.find(nextItem => prevItem.name === nextItem.name);
		
		return exists ? acc : [prevItem,...acc];
	}, next);
}


const newFiles = mergeObjectArraysByName(stateFiles, files)

console.log(newFiles)
console.log(newFiles.length)