Using XCTest in the swift repl or standalone script

xctesting_in_repl_or_script.swift

// Start repl with:
// $ xcrun swift -F xcrun swift -F /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Frameworks/

// Or run as script:
// $ xcrun swift -F xcrun swift -F /Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Frameworks/ %


import Foundation

if dlopen("/Applications/Xcode.app/Contents/Developer/Platforms/iPhoneOS.platform/Developer/Library/Frameworks/XCTest.framework/XCTest", RTLD_NOW) == nil {
  perror(dlerror())
}
if dlopen("/Applications/Xcode.app/Contents/Developer/Toolchains/XcodeDefault.xctoolchain/usr/lib/swift/iphoneos/libswiftXCTest.dylib", RTLD_NOW) == nil {
  perror(dlerror())
}

import XCTest

class ATest : XCTestCase {
    func testIt() {
        XCTAssertTrue(false, "Now I see this!")
    }
    func testThat() {
        XCTAssertNil(nil, "Passes!")
    }
}

class BTest : XCTestCase {
  func testIt() {
    XCTAssertFalse(false, "whatever")
  }
  func testThat() {
    XCTAssertEqual(1, 0, "I fail too")
  }
}

// MARK: -
func selectors<T: XCTestCase>(forType type: T.Type) -> [Selector] {
  var selectors = [Selector]()
  var count : UInt32 = 0
  let methods = class_copyMethodList(type, &count)!
  for i in 0..<count {
    let method = methods.advanced(by: Int(i)).pointee!
    selectors.append(method_getName(method)!)
  }
  return selectors
}

func runTests(_ types: XCTestCase.Type...) {
  let suite = XCTestSuite(name: "Required")
  for t in types {
    let tests = selectors(forType: t).filter() { String($0).hasPrefix("test") }
    tests.map(t.init)
         .forEach(suite.addTest)
  }
  suite.run()
}

runTests(ATest.self, BTest.self)