lib/tests/util/support/Pipe.test.ts

import { expect } from 'chai'
import * as sinon from 'sinon'
import { Pipe, AsyncPipe } from '../../../lib'

describe('util -> support -> Pipe', () => {
    describe('static.wrap', () => {
        it('should return a Pipe containing the input value', () => {
            const sym = Symbol()
            const pipe = Pipe.wrap(sym)
            expect(pipe).to.be.an.instanceof(Pipe)
            expect(pipe.get()).to.be.equal(sym)
        })
    })

    describe('constructor', () => {
        it('should instantiate a Pipe with the input value', () => {
            const sym = Symbol()
            const pipe = new Pipe(sym)
            expect(pipe).to.be.an.instanceof(Pipe)
            expect(pipe.get()).to.be.equal(sym)
        })
    })

    describe('tap', () => {
        const pipe = Pipe.wrap(123)

        it('should call the input operator with the value of the pipe', () => {
            const spy = sinon.spy()
            pipe.tap(spy)
            expect(spy.callCount).to.be.equal(1)
            expect(spy.firstCall.firstArg).to.be.equal(123)
        })

        it('should return a new Pipe', () => {
            const ret = pipe.tap(x => x)
            expect(ret).to.be.an.instanceof(Pipe)
            expect(ret).to.not.be.equal(pipe)
        })

        it('should return the operator value in the new pipe', () => {
            const ret = pipe.tap(() => 456)
            expect(ret.get()).to.be.equal(456)
        })

        it('should not modify the base pipe', () => {
            pipe.tap(() => false)
            expect(pipe.get()).to.be.equal(123)
        })
    })

    describe('peek', () => {
        const pipe = Pipe.wrap(123)

        it('should call the input operator with the value of the pipe', () => {
            const spy = sinon.spy()
            pipe.peek(spy)
            expect(spy.callCount).to.be.equal(1)
            expect(spy.firstCall.firstArg).to.be.equal(123)
        })

        it('should return the same pipe', () => {
            const ret = pipe.peek(x => x)
            expect(ret).to.be.eql(pipe)
        })

        it('should not modify the base pipe', () => {
            pipe.peek(() => false)
            expect(pipe.get()).to.be.equal(123)
        })
    })

    describe('when', () => {
        const pipe = Pipe.wrap(123)

        describe('condition is true', () => {
            it('should call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.when(true, spy)
                expect(spy.callCount).to.be.equal(1)
                expect(spy.firstCall.firstArg).to.be.equal(123)
            })

            it('should return a new Pipe', () => {
                const ret = pipe.when(true, x => x)
                expect(ret).to.be.an.instanceof(Pipe)
                expect(ret).to.not.be.equal(pipe)
            })

            it('should return the operator value in the new pipe', () => {
                const ret = pipe.when(true, () => 456)
                expect(ret.get()).to.be.equal(456)
            })

            it('should not modify the base pipe', () => {
                pipe.when(true, () => 456)
                expect(pipe.get()).to.be.equal(123)
            })
        })

        describe('condition evaluates to true', () => {
            it('should call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.when(() => true, spy)
                expect(spy.callCount).to.be.equal(1)
                expect(spy.firstCall.firstArg).to.be.equal(123)
            })

            it('should return a new Pipe', () => {
                const ret = pipe.when(() => true, x => x)
                expect(ret).to.be.an.instanceof(Pipe)
                expect(ret).to.not.be.equal(pipe)
            })

            it('should return the operator value in the new pipe', () => {
                const ret = pipe.when(() => true, () => 456)
                expect(ret.get()).to.be.equal(456)
            })

            it('should not modify the base pipe', () => {
                pipe.when(() => true, () => 456)
                expect(pipe.get()).to.be.equal(123)
            })
        })

        describe('condition is false', () => {
            it('should not call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.when(false, spy)
                expect(spy.callCount).to.be.equal(0)
            })

            it('should return the same Pipe', () => {
                const ret = pipe.when(false, x => x)
                expect(ret).to.be.equal(pipe)
            })
        })

        describe('condition evaluates to false', () => {
            it('should not call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.when(() => false, spy)
                expect(spy.callCount).to.be.equal(0)
            })

            it('should return the same Pipe', () => {
                const ret = pipe.when(() => false, x => x)
                expect(ret).to.be.equal(pipe)
            })
        })
    })

    describe('unless', () => {
        const pipe = Pipe.wrap(123)

        describe('condition is false', () => {
            it('should call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.unless(false, spy)
                expect(spy.callCount).to.be.equal(1)
                expect(spy.firstCall.firstArg).to.be.equal(123)
            })

            it('should return a new Pipe', () => {
                const ret = pipe.unless(false, x => x)
                expect(ret).to.be.an.instanceof(Pipe)
                expect(ret).to.not.be.equal(pipe)
            })

            it('should return the operator value in the new pipe', () => {
                const ret = pipe.unless(false, () => 456)
                expect(ret.get()).to.be.equal(456)
            })

            it('should not modify the base pipe', () => {
                pipe.unless(false, () => 456)
                expect(pipe.get()).to.be.equal(123)
            })
        })

        describe('condition evaluates to false', () => {
            it('should call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.unless(() => false, spy)
                expect(spy.callCount).to.be.equal(1)
                expect(spy.firstCall.firstArg).to.be.equal(123)
            })

            it('should return a new Pipe', () => {
                const ret = pipe.unless(() => false, x => x)
                expect(ret).to.be.an.instanceof(Pipe)
                expect(ret).to.not.be.equal(pipe)
            })

            it('should return the operator value in the new pipe', () => {
                const ret = pipe.unless(() => false, () => 456)
                expect(ret.get()).to.be.equal(456)
            })

            it('should not modify the base pipe', () => {
                pipe.unless(() => false, () => 456)
                expect(pipe.get()).to.be.equal(123)
            })
        })

        describe('condition is true', () => {
            it('should not call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.unless(true, spy)
                expect(spy.callCount).to.be.equal(0)
            })

            it('should return the same Pipe', () => {
                const ret = pipe.unless(true, x => x)
                expect(ret).to.be.equal(pipe)
            })
        })

        describe('condition evaluates to true', () => {
            it('should not call the input operator with the value of the pipe', () => {
                const spy = sinon.spy()
                pipe.unless(() => true, spy)
                expect(spy.callCount).to.be.equal(0)
            })

            it('should return the same Pipe', () => {
                const ret = pipe.unless(() => true, x => x)
                expect(ret).to.be.equal(pipe)
            })
        })
    })

    describe('get', () => {
        it('should return the value in the pipe', () => {
            expect(Pipe.wrap(123).get())
                .to.be.equal(123)

            const sym = Symbol()
            expect(Pipe.wrap(sym).get())
                .to.be.eql(sym)
        })
    })

    describe('async', () => {
        it('should return an async pipe', () => {
            expect(Pipe.wrap(123).async())
                .to.be.an.instanceof(AsyncPipe)
        })
    })
})