Example
We can use jasmine.createSpy() to create a standalone spy. This is often useful if we need to pass a function as a callback to another function and want to test how it is used.
// source code
function each(arr, fn) {
arr.forEach(fn);
}
// test code
describe('each', function() {
let mockFn = jasmine.createSpy();
it('calls a function for each item in the array ', function() {
let arr = [1,2,3,4,5]
each(arr, mockFn);
expect(mockFn.calls.count()).toBe(arr.length);
})
});
