URLProtocolMock.swift

URLProtocolMock.swift

import Foundation

final class URLProtocolMock: URLProtocol {
    static var data = [URL: (error: Error?, data: Data?)]()

    override class func canInit(with request: URLRequest) -> Bool {
        return true
    }

    override class func canonicalRequest(for request: URLRequest) -> URLRequest {
        return request
    }

    override func startLoading() {
        guard let url = request.url, let (error, data) = URLProtocolMock.data[url] else {
            fatalError("\(String(describing: request.url)) not mocked")
        }

        if let data {
            self.client?.urlProtocol(self, didLoad: data)
        } else if let error {
            self.client?.urlProtocol(self, didFailWithError: error)
        } else {
            fatalError("Mock should contain either data or error")
        }

        self.client?.urlProtocolDidFinishLoading(self)
    }

    override func stopLoading() {}
}