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spec-js/observables/fromEvent-spec.js

"use strict";
var chai_1 = require('chai');
var Rx = require('../../dist/cjs/Rx');
var Observable = Rx.Observable;
/** @test {fromEvent} */
describe('Observable.fromEvent', function () {
    asDiagram('fromEvent(element, \'click\')')('should create an observable of click on the element', function () {
        var target = {
            addEventListener: function (eventType, listener) {
                Observable.timer(50, 20, rxTestScheduler)
                    .mapTo('ev')
                    .take(2)
                    .concat(Observable.never())
                    .subscribe(listener);
            },
            removeEventListener: function () { return void 0; },
            dispatchEvent: function () { return void 0; },
        };
        var e1 = Observable.fromEvent(target, 'click');
        var expected = '-----x-x---';
        expectObservable(e1).toBe(expected, { x: 'ev' });
    });
    it('should setup an event observable on objects with "on" and "off" ', function () {
        var onEventName;
        var onHandler;
        var offEventName;
        var offHandler;
        var obj = {
            on: function (a, b) {
                onEventName = a;
                onHandler = b;
            },
            off: function (a, b) {
                offEventName = a;
                offHandler = b;
            }
        };
        var subscription = Observable.fromEvent(obj, 'click')
            .subscribe(function () {
            //noop
        });
        subscription.unsubscribe();
        chai_1.expect(onEventName).to.equal('click');
        chai_1.expect(typeof onHandler).to.equal('function');
        chai_1.expect(offEventName).to.equal(onEventName);
        chai_1.expect(offHandler).to.equal(onHandler);
    });
    it('should setup an event observable on objects with "addEventListener" and "removeEventListener" ', function () {
        var onEventName;
        var onHandler;
        var offEventName;
        var offHandler;
        var obj = {
            addEventListener: function (a, b, useCapture) {
                onEventName = a;
                onHandler = b;
            },
            removeEventListener: function (a, b, useCapture) {
                offEventName = a;
                offHandler = b;
            }
        };
        var subscription = Observable.fromEvent(obj, 'click')
            .subscribe(function () {
            //noop
        });
        subscription.unsubscribe();
        chai_1.expect(onEventName).to.equal('click');
        chai_1.expect(typeof onHandler).to.equal('function');
        chai_1.expect(offEventName).to.equal(onEventName);
        chai_1.expect(offHandler).to.equal(onHandler);
    });
    it('should setup an event observable on objects with "addListener" and "removeListener" ', function () {
        var onEventName;
        var onHandler;
        var offEventName;
        var offHandler;
        var obj = {
            addListener: function (a, b) {
                onEventName = a;
                onHandler = b;
            },
            removeListener: function (a, b) {
                offEventName = a;
                offHandler = b;
            }
        };
        var subscription = Observable.fromEvent(obj, 'click')
            .subscribe(function () {
            //noop
        });
        subscription.unsubscribe();
        chai_1.expect(onEventName).to.equal('click');
        chai_1.expect(typeof onHandler).to.equal('function');
        chai_1.expect(offEventName).to.equal(onEventName);
        chai_1.expect(offHandler).to.equal(onHandler);
    });
    it('should error on invalid event targets', function () {
        var obj = {
            addListener: function () {
                //noop
            }
        };
        var subscribe = function () { return Observable.fromEvent(obj, 'click').subscribe(); };
        chai_1.expect(subscribe).to.throw(TypeError, 'Invalid event target');
    });
    it('should pass through options to addEventListener', function () {
        var actualOptions;
        var expectedOptions = { capture: true, passive: true };
        var obj = {
            addEventListener: function (a, b, c) {
                actualOptions = c;
            },
            removeEventListener: function (a, b, c) {
                //noop
            }
        };
        var subscription = Observable.fromEvent(obj, 'click', expectedOptions)
            .subscribe(function () {
            //noop
        });
        subscription.unsubscribe();
        chai_1.expect(actualOptions).to.equal(expectedOptions);
    });
    it('should pass through events that occur', function (done) {
        var send;
        var obj = {
            on: function (name, handler) {
                send = handler;
            },
            off: function () {
                //noop
            }
        };
        Observable.fromEvent(obj, 'click').take(1)
            .subscribe(function (e) {
            chai_1.expect(e).to.equal('test');
        }, function (err) {
            done(new Error('should not be called'));
        }, function () {
            done();
        });
        send('test');
    });
    it('should pass through events that occur and use the selector if provided', function (done) {
        var send;
        var obj = {
            on: function (name, handler) {
                send = handler;
            },
            off: function () {
                //noop
            }
        };
        function selector(x) {
            return x + '!';
        }
        Observable.fromEvent(obj, 'click', selector).take(1)
            .subscribe(function (e) {
            chai_1.expect(e).to.equal('test!');
        }, function (err) {
            done(new Error('should not be called'));
        }, function () {
            done();
        });
        send('test');
    });
    it('should not fail if no event arguments are passed and the selector does not return', function (done) {
        var send;
        var obj = {
            on: function (name, handler) {
                send = handler;
            },
            off: function () {
                //noop
            }
        };
        function selector() {
            //noop
        }
        Observable.fromEvent(obj, 'click', selector).take(1)
            .subscribe(function (e) {
            chai_1.expect(e).not.exist;
        }, function (err) {
            done(new Error('should not be called'));
        }, function () {
            done();
        });
        send();
    });
    it('should return a value from the selector if no event arguments are passed', function (done) {
        var send;
        var obj = {
            on: function (name, handler) {
                send = handler;
            },
            off: function () {
                //noop
            }
        };
        function selector() {
            return 'no arguments';
        }
        Observable.fromEvent(obj, 'click', selector).take(1)
            .subscribe(function (e) {
            chai_1.expect(e).to.equal('no arguments');
        }, function (err) {
            done(new Error('should not be called'));
        }, function () {
            done();
        });
        send();
    });
    it('should pass multiple arguments to selector from event emitter', function (done) {
        var send;
        var obj = {
            on: function (name, handler) {
                send = handler;
            },
            off: function () {
                //noop
            }
        };
        function selector(x, y, z) {
            return [].slice.call(arguments);
        }
        Observable.fromEvent(obj, 'click', selector).take(1)
            .subscribe(function (e) {
            chai_1.expect(e).to.deep.equal([1, 2, 3]);
        }, function (err) {
            done(new Error('should not be called'));
        }, function () {
            done();
        });
        send(1, 2, 3);
    });
    it('should not throw an exception calling toString on obj with a null prototype', function (done) {
        // NOTE: Can not test with Object.create(null) or `class Foo extends null`
        // due to TypeScript bug. https://github.com/Microsoft/TypeScript/issues/1108
        var NullProtoEventTarget = (function () {
            function NullProtoEventTarget() {
            }
            NullProtoEventTarget.prototype.on = function () { };
            NullProtoEventTarget.prototype.off = function () { };
            return NullProtoEventTarget;
        }());
        NullProtoEventTarget.prototype.toString = null;
        var obj = new NullProtoEventTarget();
        chai_1.expect(function () {
            Observable.fromEvent(obj, 'foo').subscribe();
            done();
        }).to.not.throw(TypeError);
    });
});
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