I've encountered a challenge with a method that is triggered by a d3 timer. Each time the method runs, it emits an object containing several values. One of these values is meant to increase gradually over time. My goal is to create a test to verify whether these values are actually ascending or not.
To address this issue, I decided to subscribe to the event emitter within my test. During the subscription process, I capture the received objects in a local array. Subsequently, I check if array[i] is less than array[i+1], indicating that the values are in fact increasing. Although my logic seems correct, I'm puzzled by an error message from Jasmine stating that the spec has no expectations, despite having one defined.
Below is the relevant code snippet:
let x = d3.timer((elapsed) => {
this.method(); // invoke the function
if(elapsed >= 500) {
x.stop(); // halt the timer execution.
}
});
method(elapsed) {
// perform necessary actions
if(elapsed > 500) {
this.output.emit({x: somevalue, y: somevalue, f: increasingvalue });
}
}
The Jasmine Spec:
it('my spec', inject([JumpService], (service: JumpService) => {
array = [];
//invoke service method
service.output.subscribe(e => {
array.push(e);
//A console statement will provide length and pushed object details.
for(let i = 0; i< array.length - 1; i++) {
expect(array[i].f).toBeLessThan(array[i+1].f);
}
});
}));
Could there be any mistakes in my approach? How should I handle such scenarios effectively? Any guidance would be greatly appreciated.
Thank you.