UI Test reporting

Step.swift

public typealias Given = Step
public typealias When = Step
public typealias Then = Step
public typealias And = Step

public struct Step {
	
	@discardableResult
	public init(_ handler: @autoclosure () -> Void, file: String = #file, line lineNumber: Int = #line) {
		step(handler, file: file, line: lineNumber)
	}
	
	@discardableResult
	public init(I handler: @autoclosure () -> Void, file: String = #file, line lineNumber: Int = #line) {
		step(handler, file: file, line: lineNumber)
	}
	
	@discardableResult
	public init(_ handler: () -> Void, file: String = #file, line lineNumber: Int = #line) {
		step(handler, file: file, line: lineNumber)
	}
	
	@discardableResult
	public init(I handler: () -> Void, file: String = #file, line lineNumber: Int = #line) {
		step(handler, file: file, line: lineNumber)
	}
	
	private func step(_ handler: () -> Void, file: String, line lineNumber: Int) {
		let codeLine = CodeLineCache.line(in: file, at: lineNumber)
		XCTContext.runActivity(named: codeLine) { _ in
			handler()
		}
	}
}

private struct CodeLineCache {
	private static var cache = [String: [String.SubSequence]]()
	
	static func line(in file: String, at lineNumber: Int) -> String {
		if let lines = cache[file] {
			return getLine(lineNumber, from: lines)
		}
		let lines = getLines(of: file)
		cache[file] = lines
		return getLine(lineNumber, from: lines)
	}
	
	private static func getLine(_ lineNumber: Int, from lines: [String.SubSequence]) -> String {
		let lineIndex = lineNumber - 1
		return String(lines[lineIndex]).trimmingCharacters(in: .whitespacesAndNewlines)
	}
	
	private static func getLines(of file: String) -> [String.SubSequence] {
		return (try? String(contentsOf: URL(fileURLWithPath: file)).split(separator: "\n", omittingEmptySubsequences: false)) ?? []
	}
}