XCTestCase+Fixture.swift

extension XCTestCase {

    enum FixtureError: Error {
        case resourceNotFound
        case invalidFormat
    }

    /// Loads the json fixture with the given name from disk and returns a json object.
    /// - Parameter fileName: The anme of the fixture on disk (without the type suffix).
    /// - Throws: Any errors encountered during the process.
    func jsonFixture(named fileName: String) throws -> [String: Any] {
        let bundle = Bundle(for: type(of: self))
        let path = bundle.path(forResource: fileName, ofType: "json")
        guard let url = path.flatMap(URL.init(fileURLWithPath:)) else { throw FixtureError.resourceNotFound }
        let data = try Data(contentsOf: url)
        guard let json = try JSONSerialization.jsonObject(with: data, options: []) as? [String: Any] else { throw FixtureError.invalidFormat }
        return json
    }

}