Protocol to create models from json

ModelMockable.swift

import Foundation

final class MockableTests {
    struct MockNotFound: Error {
        let message: String
    }
}

extension Bundle {
    static let tests = Bundle(for: MockableTests.self)
}

protocol ModelMockable: Decodable {
    static func mock(fileName: String) throws -> Self
}

extension ModelMockable {
    // tries to find <Model>.json file in test bundle
    static func mock(fileName: String = "\(Self.self)") throws -> Self {
        guard let jsonURL = Bundle.tests.url(forResource: fileName, withExtension: "json") else {
            throw MockableTests.MockNotFound(message: "Unable to find json mocks for \(fileName)")
        }
        let json = try Data(contentsOf: jsonURL)
        return try JSONDecoder().decode(Self.self, from: json)
    }
}