Load JSON file

XCTest+loadJSON.swift

import XCTest

extension XCTest {
    func loadFromJSON<T: Codable>(jsonFileName filename: String) -> T? {
        guard let url = Bundle(for: type(of: self)).url(forResource: filename, withExtension: "json") else {
            XCTFail("Unable to read \(filename) from stub")
            return nil
        }

        do {
            let contents = try Data(contentsOf: url)
            return try JSONDecoder().decode(T.self, from: contents)
        } catch {
            XCTFail("Unable to read \(filename) from stub")
            return nil
        }
    }

    // wrapper for removing nil value
    func fromJson<T: Codable>(_ filename: String) -> T {
        return loadFromJSON(jsonFileName: filename)!
    }
}