spec-js/operators/throttle-spec.js
"use strict";
var chai_1 = require('chai');
var Rx = require('../../dist/cjs/Rx');
var Observable = Rx.Observable;
/** @test {throttle} */
describe('Observable.prototype.throttle', function () {
asDiagram('throttle')('should immediately emit the first value in each time window', function () {
var e1 = hot('-a-xy-----b--x--cxxx-|');
var e1subs = '^ !';
var e2 = cold('----| ');
var e2subs = [' ^ ! ',
' ^ ! ',
' ^ ! '];
var expected = '-a--------b-----c----|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should simply mirror the source if values are not emitted often enough', function () {
var e1 = hot('-a--------b-----c----|');
var e1subs = '^ !';
var e2 = cold('----| ');
var e2subs = [' ^ ! ',
' ^ ! ',
' ^ ! '];
var expected = '-a--------b-----c----|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should throttle with duration Observable using next to close the duration', function () {
var e1 = hot('-a-xy-----b--x--cxxx-|');
var e1subs = '^ !';
var e2 = cold('----x-y-z ');
var e2subs = [' ^ ! ',
' ^ ! ',
' ^ ! '];
var expected = '-a--------b-----c----|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should interrupt source and duration when result is unsubscribed early', function () {
var e1 = hot('-a-x-y-z-xyz-x-y-z----b--x-x-|');
var unsub = ' ! ';
var e1subs = '^ ! ';
var e2 = cold('------------------| ');
var e2subs = ' ^ ! ';
var expected = '-a------------- ';
var result = e1.throttle(function () { return e2; });
expectObservable(result, unsub).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should not break unsubscription chains when result is unsubscribed explicitly', function () {
var e1 = hot('-a-x-y-z-xyz-x-y-z----b--x-x-|');
var e1subs = '^ ! ';
var e2 = cold('------------------| ');
var e2subs = ' ^ ! ';
var expected = '-a------------- ';
var unsub = ' ! ';
var result = e1
.mergeMap(function (x) { return Observable.of(x); })
.throttle(function () { return e2; })
.mergeMap(function (x) { return Observable.of(x); });
expectObservable(result, unsub).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should handle a busy producer emitting a regular repeating sequence', function () {
var e1 = hot('abcdefabcdefabcdefabcdefa|');
var e1subs = '^ !';
var e2 = cold('-----| ');
var e2subs = ['^ ! ',
' ^ ! ',
' ^ ! ',
' ^ ! ',
' ^!'];
var expected = 'a-----a-----a-----a-----a|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should mirror source if durations are always empty', function () {
var e1 = hot('abcdefabcdefabcdefabcdefa|');
var e1subs = '^ !';
var e2 = cold('|');
var expected = 'abcdefabcdefabcdefabcdefa|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
});
it('should take only the first value emitted if duration is a never', function () {
var e1 = hot('----abcdefabcdefabcdefabcdefa|');
var e1subs = '^ !';
var e2 = cold('-');
var e2subs = ' ^ !';
var expected = '----a------------------------|';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should unsubscribe duration Observable when source raise error', function () {
var e1 = hot('----abcdefabcdefabcdefabcdefa#');
var e1subs = '^ !';
var e2 = cold('-');
var e2subs = ' ^ !';
var expected = '----a------------------------#';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should raise error as soon as just-throw duration is used', function () {
var e1 = hot('----abcdefabcdefabcdefabcdefa|');
var e1subs = '^ ! ';
var e2 = cold('#');
var e2subs = ' (^!) ';
var expected = '----(a#) ';
var result = e1.throttle(function () { return e2; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
it('should throttle using durations of constying lengths', function () {
var e1 = hot('abcdefabcdabcdefghabca| ');
var e1subs = '^ ! ';
var e2 = [cold('-----| '),
cold('---| '),
cold('-------| '),
cold('--| '),
cold('----|')];
var e2subs = ['^ ! ',
' ^ ! ',
' ^ ! ',
' ^ ! ',
' ^! '];
var expected = 'a-----a---a-------a--a| ';
var i = 0;
var result = e1.throttle(function () { return e2[i++]; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
for (var j = 0; j < e2.length; j++) {
expectSubscriptions(e2[j].subscriptions).toBe(e2subs[j]);
}
});
it('should propagate error from duration Observable', function () {
var e1 = hot('abcdefabcdabcdefghabca| ');
var e1subs = '^ ! ';
var e2 = [cold('-----| '),
cold('---| '),
cold('-------# ')];
var e2subs = ['^ ! ',
' ^ ! ',
' ^ ! '];
var expected = 'a-----a---a------# ';
var i = 0;
var result = e1.throttle(function () { return e2[i++]; });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
for (var j = 0; j < e2.length; j++) {
expectSubscriptions(e2[j].subscriptions).toBe(e2subs[j]);
}
});
it('should propagate error thrown from durationSelector function', function () {
var e1 = hot('abcdefabcdabcdefghabca| ');
var e1subs = '^ ! ';
var e2 = [cold('-----| '),
cold('---| '),
cold('-------| ')];
var e2subs = ['^ ! ',
' ^ ! '];
var expected = 'a-----a---# ';
var i = 0;
var result = e1.throttle(function () {
if (i === 2) {
throw 'error';
}
return e2[i++];
});
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
for (var j = 0; j < e2subs.length; j++) {
expectSubscriptions(e2[j].subscriptions).toBe(e2subs[j]);
}
});
it('should complete when source does not emit', function () {
var e1 = hot('-----|');
var subs = '^ !';
var expected = '-----|';
function durationSelector() { return cold('-----|'); }
expectObservable(e1.throttle(durationSelector)).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(subs);
});
it('should raise error when source does not emit and raises error', function () {
var e1 = hot('-----#');
var subs = '^ !';
var expected = '-----#';
function durationSelector() { return cold('-----|'); }
expectObservable(e1.throttle(durationSelector)).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(subs);
});
it('should handle an empty source', function () {
var e1 = cold('|');
var subs = '(^!)';
var expected = '|';
function durationSelector() { return cold('-----|'); }
expectObservable(e1.throttle(durationSelector)).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(subs);
});
it('should handle a never source', function () {
var e1 = cold('-');
var subs = '^';
var expected = '-';
function durationSelector() { return cold('-----|'); }
expectObservable(e1.throttle(durationSelector)).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(subs);
});
it('should handle a throw source', function () {
var e1 = cold('#');
var subs = '(^!)';
var expected = '#';
function durationSelector() { return cold('-----|'); }
expectObservable(e1.throttle(durationSelector)).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(subs);
});
it('should throttle by promise resolves', function (done) {
var e1 = Observable.concat(Observable.of(1), Observable.timer(10).mapTo(2), Observable.timer(10).mapTo(3), Observable.timer(50).mapTo(4));
var expected = [1, 2, 3, 4];
e1.throttle(function () {
return new Promise(function (resolve) { resolve(42); });
}).subscribe(function (x) {
chai_1.expect(x).to.equal(expected.shift());
}, function () {
done(new Error('should not be called'));
}, function () {
chai_1.expect(expected.length).to.equal(0);
done();
});
});
it('should raise error when promise rejects', function (done) {
var e1 = Observable.concat(Observable.of(1), Observable.timer(10).mapTo(2), Observable.timer(10).mapTo(3), Observable.timer(50).mapTo(4));
var expected = [1, 2, 3];
var error = new Error('error');
e1.throttle(function (x) {
if (x === 3) {
return new Promise(function (resolve, reject) { reject(error); });
}
else {
return new Promise(function (resolve) { resolve(42); });
}
}).subscribe(function (x) {
chai_1.expect(x).to.equal(expected.shift());
}, function (err) {
chai_1.expect(err).to.be.an('error', 'error');
chai_1.expect(expected.length).to.equal(0);
done();
}, function () {
done(new Error('should not be called'));
});
});
describe('throttle(fn, { leading: true, trailing: true })', function () {
asDiagram('throttle(fn, { leading: true, trailing: true })')('should immediately emit the first value in each time window', function () {
var e1 = hot('-a-xy-----b--x--cxxx--|');
var e1subs = '^ !';
var e2 = cold('----| ');
var e2subs = [' ^ ! ',
' ^ ! ',
' ^ ! '];
var expected = '-a---y----b---x-c---x-|';
var result = e1.throttle(function () { return e2; }, { leading: true, trailing: true });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
});
describe('throttle(fn, { leading: false, trailing: true })', function () {
asDiagram('throttle(fn, { leading: false, trailing: true })')('should immediately emit the first value in each time window', function () {
var e1 = hot('-a-xy-----b--x--cxxx--|');
var e1subs = '^ !';
var e2 = cold('----| ');
var e2subs = [' ^ ! ',
' ^ ! ',
' ^ ! '];
var expected = '-----y--------x-----x-|';
var result = e1.throttle(function () { return e2; }, { leading: false, trailing: true });
expectObservable(result).toBe(expected);
expectSubscriptions(e1.subscriptions).toBe(e1subs);
expectSubscriptions(e2.subscriptions).toBe(e2subs);
});
});
});
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