@reactivex/rxjs/spec-js/operators/filter-spec.js

Reactive Extensions for modern JavaScript

"use strict";
var chai_1 = require('chai');
var Rx = require('../../dist/cjs/Rx');
var Observable = Rx.Observable;
/** @test {filter} */
describe('Observable.prototype.filter', function () {
    function oddFilter(x) {
        return (+x) % 2 === 1;
    }
    function isPrime(i) {
        if (+i <= 1) {
            return false;
        }
        var max = Math.floor(Math.sqrt(+i));
        for (var j = 2; j <= max; ++j) {
            if (+i % j === 0) {
                return false;
            }
        }
        return true;
    }
    asDiagram('filter(x => x % 2 === 1)')('should filter out even values', function () {
        var source = hot('--0--1--2--3--4--|');
        var subs = '^                !';
        var expected = '-----1-----3-----|';
        expectObservable(source.filter(oddFilter)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^                  !';
        var expected = '--3---5----7-------|';
        expectObservable(source.filter(isPrime)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter with an always-true predicate', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '--3-4-5-6--7-8--9--|';
        var predicate = function () { return true; };
        expectObservable(source.filter(predicate)).toBe(expected);
    });
    it('should filter with an always-false predicate', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '-------------------|';
        var predicate = function () { return false; };
        expectObservable(source.filter(predicate)).toBe(expected);
    });
    it('should filter in only prime numbers, source unsubscribes early', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^           !       ';
        var unsub = '            !       ';
        var expected = '--3---5----7-       ';
        expectObservable(source.filter(isPrime), unsub).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers, source throws', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--#');
        var subs = '^                  !';
        var expected = '--3---5----7-------#';
        expectObservable(source.filter(isPrime)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers, but predicate throws', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^       !           ';
        var expected = '--3---5-#           ';
        var invoked = 0;
        function predicate(x, index) {
            invoked++;
            if (invoked === 4) {
                throw 'error';
            }
            return isPrime(x);
        }
        ;
        expectObservable(source.filter(predicate)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers, predicate with index', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^                  !';
        var expected = '--3--------7-------|';
        function predicate(x, i) {
            return isPrime((+x) + i * 10);
        }
        expectObservable(source.filter(predicate)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should invoke predicate once for each checked value', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '--3---5----7-------|';
        var invoked = 0;
        var predicate = function (x) {
            invoked++;
            return isPrime(x);
        };
        var r = source
            .filter(predicate)
            .do(null, null, function () {
            chai_1.expect(invoked).to.equal(7);
        });
        expectObservable(r).toBe(expected);
    });
    it('should filter in only prime numbers, predicate with index, ' +
        'source unsubscribes early', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^           !       ';
        var unsub = '            !       ';
        var expected = '--3--------7-       ';
        function predicate(x, i) {
            return isPrime((+x) + i * 10);
        }
        expectObservable(source.filter(predicate), unsub).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers, predicate with index, source throws', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--#');
        var subs = '^                  !';
        var expected = '--3--------7-------#';
        function predicate(x, i) {
            return isPrime((+x) + i * 10);
        }
        expectObservable(source.filter(predicate)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should filter in only prime numbers, predicate with index and throws', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^       !           ';
        var expected = '--3-----#           ';
        var invoked = 0;
        function predicate(x, i) {
            invoked++;
            if (invoked === 4) {
                throw 'error';
            }
            return isPrime((+x) + i * 10);
        }
        ;
        expectObservable(source.filter(predicate)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should compose with another filter to allow multiples of six', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '--------6----------|';
        expectObservable(source
            .filter(function (x) { return x % 2 === 0; })
            .filter(function (x) { return x % 3 === 0; })).toBe(expected);
    });
    it('should be able to accept and use a thisArg', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '--------6----------|';
        function Filterer() {
            this.filter1 = function (x) { return x % 2 === 0; };
            this.filter2 = function (x) { return x % 3 === 0; };
        }
        var filterer = new Filterer();
        expectObservable(source
            .filter(function (x) { return this.filter1(x); }, filterer)
            .filter(function (x) { return this.filter2(x); }, filterer)
            .filter(function (x) { return this.filter1(x); }, filterer)).toBe(expected);
    });
    it('should be able to use filter and map composed', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var expected = '----a---b----c-----|';
        var values = { a: 16, b: 36, c: 64 };
        expectObservable(source
            .filter(function (x) { return x % 2 === 0; })
            .map(function (x) { return x * x; })).toBe(expected, values);
    });
    it('should propagate errors from the source', function () {
        var source = hot('--0--1--2--3--4--#');
        var subs = '^                !';
        var expected = '-----1-----3-----#';
        expectObservable(source.filter(oddFilter)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should support Observable.empty', function () {
        var source = cold('|');
        var subs = '(^!)';
        var expected = '|';
        expectObservable(source.filter(oddFilter)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should support Observable.never', function () {
        var source = cold('-');
        var subs = '^';
        var expected = '-';
        expectObservable(source.filter(oddFilter)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should support Observable.throw', function () {
        var source = cold('#');
        var subs = '(^!)';
        var expected = '#';
        expectObservable(source.filter(oddFilter)).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
    it('should send errors down the error path', function (done) {
        Observable.of(42).filter((function (x, index) {
            throw 'bad';
        }))
            .subscribe(function (x) {
            done(new Error('should not be called'));
        }, function (err) {
            chai_1.expect(err).to.equal('bad');
            done();
        }, function () {
            done(new Error('should not be called'));
        });
    });
    it('should not break unsubscription chain when unsubscribed explicitly', function () {
        var source = hot('-1--2--^-3-4-5-6--7-8--9--|');
        var subs = '^           !       ';
        var unsub = '            !       ';
        var expected = '--3---5----7-       ';
        var r = source
            .mergeMap(function (x) { return Observable.of(x); })
            .filter(isPrime)
            .mergeMap(function (x) { return Observable.of(x); });
        expectObservable(r, unsub).toBe(expected);
        expectSubscriptions(source.subscriptions).toBe(subs);
    });
});
//# sourceMappingURL=filter-spec.js.map