when called with
- <function> [when] called with <array-like> <assertion?>
Apply the subject function to an array of parameters, then delegate the return value to another assertion.
function add(a, b) {
return a + b;
}
expect(add, 'when called with', [1, 2], 'to equal', 3);
In case of a failing expectation you get the following output:
expect(add, 'when called with', [1, 2], 'to equal', 9);
expected function add(a, b) { return a + b; } when called with [ 1, 2 ] to equal 9
expected 3 to equal 9
If you don't provide an assertion to delegate to, the return value will be provided as the fulfillment value of the promise:
return expect(add, 'called with', [1, 2]).then(function (result) {
expect(result, 'to equal', 3);
});