sabirvirtuoso/Kraken

//
//  Kraken
//
//  Copyright (c) 2016 Syed Sabir Salman-Al-Musawi <sabirvirtuoso@gmail.com>
//
//  Permission is hereby granted, free of charge, to any person obtaining a copy
//  of this software and associated documentation files (the "Software"), to deal
//  in the Software without restriction, including without limitation the rights
//  to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
//  copies of the Software, and to permit persons to whom the Software is
//  furnished to do so, subject to the following conditions:
//
//  The above copyright notice and this permission notice shall be included in
//  all copies or substantial portions of the Software.
//
//  THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
//  IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
//  FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
//  AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
//  LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
//  OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
//  THE SOFTWARE.
//

import XCTest
@testable import Kraken

private protocol ServiceA: Injectable {
}

private protocol ServiceB: Injectable {
}

private protocol AutoWiredService: Injectable {
    var serviceA: ServiceA! { get set }
    var serviceB: ServiceB! { get set }
}

private class ServiceAImpl: ServiceA {
    required init() {
    }
}

private class ServiceBImpl: ServiceB {
    required init() {
    }
}

private class AutoWiredServiceImpl: AutoWiredService {

    var serviceA: ServiceA!
    var serviceB: ServiceB!

    required init() {
    }

    init(serviceA: ServiceA, serviceB: ServiceB) {
        self.serviceA = serviceA
        self.serviceB = serviceB
    }

}

class AutoWiringTests: XCTestCase {

    override func setUp() {
        Kraken.reset()
    }

    func testThatItCanResolveWithAutoWiring() {
        // given
        Kraken.register(ServiceA.self, implementationType: ServiceAImpl.self)
        Kraken.register(ServiceB.self, implementationType: ServiceBImpl.self)

        try! Kraken.register(AutoWiredService.self) {
            AutoWiredServiceImpl(serviceA: $0, serviceB: $1) as AutoWiredService
        }

        // when
        let service: AutoWiredService = inject(AutoWiredService.self)

        // then
        XCTAssert(service is AutoWiredServiceImpl)

        let serviceA = service.serviceA
        XCTAssertTrue(serviceA is ServiceAImpl)

        let serviceB = service.serviceB
        XCTAssertTrue(serviceB is ServiceBImpl)
    }

    func testThatAutoWiringIsNotSupportedIfNoFactoryWithArgumentIsRegistered() {
        // given
        Kraken.register(ServiceA.self, factory: { ServiceAImpl() as ServiceA })

        // when
        let serviceA = try! Kraken.resolveByAutoWiring(ServiceA.self)

        // then
        XCTAssertNil(serviceA)
    }

    func testThatAutoWiringIsNotSupportedIfAutoWiringFactoryIsNilDueToMissingDependency() {
        // given
        Kraken.register(ServiceA.self, implementationType: ServiceAImpl.self)

        try! Kraken.register(AutoWiredService.self) {
            AutoWiredServiceImpl(serviceA: $0, serviceB: $1) as AutoWiredService
        }

        // when
        let service = try! Kraken.resolveByAutoWiring(AutoWiredService.self)

        // then
        XCTAssertNil(service)
    }

    func testThatAutoWiringThrowsErrorIfAutoWiringFails() {
        // given
        Kraken.register(ServiceA.self, implementationType: ServiceAImpl.self)
        Kraken.register(ServiceB.self, implementationType: ServiceBImpl.self)

        try! Kraken.register(AutoWiredService.self) {
            AutoWiredServiceImpl(serviceA: $0, serviceB: $1) as AutoWiredService
        }

        Kraken.remove(ServiceA.self)

        // when
        AssertThrows(expression: try Kraken.resolveByAutoWiring(AutoWiredService.self)) { error in
            guard case let KrakenError.autoWiringFailed(key, _) = error else {
                return false
            }

            // then
            let expectedKey = String(describing: AutoWiredService.self)
            XCTAssertEqual(key, expectedKey)

            return true
        }
    }

}