discourse/test/javascripts/lib/debounce-promise-test.js.es6

95 lines
2.9 KiB
JavaScript

var clock, original, debounced, originalPromiseResolvesWith, callback;
var nothingFired = function(additionalMessage) {
ok(!original.called, "original function is not called " + additionalMessage);
ok(!callback.called, "debounced promise is not resolved " + additionalMessage);
};
var originalAndCallbackFiredOnce = function(additionalMessage) {
ok(original.calledOnce, "original function is called once " + additionalMessage);
ok(callback.calledOnce, "debounced promise is resolved once " + additionalMessage);
};
module("Discourse.debouncePromise", {
setup: function() {
clock = sinon.useFakeTimers();
originalPromiseResolvesWith = null;
original = sinon.spy(function() {
var promise = Ember.Deferred.create();
promise.resolve(originalPromiseResolvesWith);
return promise;
});
debounced = Discourse.debouncePromise(original, 100);
callback = sinon.spy();
},
teardown: function() {
clock.restore();
}
});
test("delays execution till the end of the timeout", function() {
debounced().then(callback);
nothingFired("immediately after calling debounced function");
clock.tick(99);
nothingFired("just before the end of the timeout");
clock.tick(1);
originalAndCallbackFiredOnce("exactly at the end of the timeout");
});
test("executes only once, no matter how many times debounced function is called during the timeout", function() {
debounced().then(callback);
debounced().then(callback);
clock.tick(100);
originalAndCallbackFiredOnce("(second call was supressed)");
});
test("prolongs the timeout when the debounced function is called for the second time during the timeout", function() {
debounced().then(callback);
clock.tick(50);
debounced().then(callback);
clock.tick(50);
nothingFired("at the end of the original timeout");
clock.tick(50);
originalAndCallbackFiredOnce("exactly at the end of the prolonged timeout");
});
test("preserves last call's context and params when executing delayed function", function() {
var firstObj = {};
var secondObj = {};
debounced.call(firstObj, "first");
debounced.call(secondObj, "second");
clock.tick(100);
ok(original.calledOn(secondObj), "the context of the second of two subsequent calls is preserved");
ok(original.calledWithExactly("second"), "param passed during the second of two subsequent calls is preserved");
});
test("can be called again after timeout passes", function() {
debounced().then(callback);
clock.tick(100);
debounced().then(callback);
clock.tick(100);
ok(original.calledTwice, "original function is called for the second time");
ok(callback.calledTwice, "debounced promise is resolved for the second time");
});
test("passes resolved value from the original promise as a param to the debounced promise's callback", function() {
originalPromiseResolvesWith = "original promise return value";
debounced().then(callback);
clock.tick(100);
ok(callback.calledWith("original promise return value"));
});