ImmutableJS fromJS() and Map() “ownerID” doesn't match

Question

I am using chai-immutable npm module for testing. Here is the test:

it("runs the test", () => {
    const initialState = Map();
    const entries = ["entry"];
    const nextState = setEntries(initialState, entries);

    expect(nextState).to.equal(fromJS({
        entries : ["entry"]
    }));
});

This is setEntries function

export function setEntries(state, entries) {
    return state.set("entries", List(entries));
}

The npm test fails:

What is this ownerID ? How to fix the issue?

EDIT:

I have created and rewritten the whole file from scratch and it worked. It was exact same replica of the previous file.

Still interested why it happened....

Answer 1

Did you have this piece of code somewhere when invoking the test runner?

import chai from 'chai';
import chaiImmutable from 'chai-immutable';

chai.use(chaiImmutable);

typically you would use that in a file, say test/test-config.js and then call your runner like this: mocha --compilers js:babel-core/register --require ./test/test-config.js --recursive

(I'm assuming you need babel compiler, but the important part there is the --require ./test/test-config.js )

Answer 2

I fix this issue with Immutable.is()

expect(is(
    nextStat,
    fromJS({entries : ["entry"]})
)).to.equal(true)