Error: Object.fromEntries is not a function

[balazsorban44]

Hi! I have a beginner question.

The following:

it("Object.fromEntries", () => {
  expect(Object.fromEntries([["a", 1]])).toEqual({a: 1})
})

Throws this error:

console.error node_modules/jest-environment-jsdom/node_modules/jsdom/lib/jsdom/virtual-console.js:29 Error: Uncaught [TypeError: Object.fromEntries is not a function]
I use CRA 3.0, but I tried in a previous version, and did not work either.

I am interested in the reason why this does not work?

Adding this: Object.fromEntries = l => l.reduce((a, [k,v]) => ({...a, [k]: v}), {}) to the test file solves the issue, but I just would like to understand the reason why I need it.

Thanks!

[ianschmitz]

The reason is that function isn't implemented yet in node. https://kangax.github.io/compat-table/es2016plus/ is a good resource to see the support of newer APIs in different browsers and node versions.

You can either use a polyfill or avoid using the API until it is has better support.