Clash Royale CLAN TAG#URR8PPP

Expect several but not all true

Suppose I have an array arr = [true, false, false, true, false].
I wish to assert that exactly two values are true in this array. Obviously, I could do something like this (with lodash):

arr = [true, false, false, true, false]

Chai.expect(_.filter(arr, item => item == true)).to.have.length(2)


Is there a more Chai-y or Jest-y way to do this?

expect(arr).toEqual(expect.arrayContaining([true, true]))

1 Answer
1

Closest assertion methods are as follows:

Both options will not suit because of your expected values being a value type and functions above use === for comparison (it can be changed, at least in Chai, but still no difference for our case).

===

// Jest example
describe('arrayContaining', () =>
const expected = [true, true];

it('does not match: not enough `true` values received', () =>
expect([true, false, false]).not.toEqual(expect.arrayContaining(expected));
);

it('does not match: not enough toatl values received', () =>
expect([true]).not.toEqual(expect.arrayContaining(expected));
);
);


Both assertions above will fail, it means that these assertion rules/functions can not spot a difference between expected and actual values in the given case.

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