for pointfree episode 153

RefreshableTests.swift

@testable import SwiftUICaseStudies
import XCTest

class RefreshableTests: XCTestCase {

  func testVanilla() async {
    var k: CheckedContinuation<Void, Never>? = nil

    let viewModel = PullToRefreshViewModel(
      fetch: {
        await withCheckedContinuation {
          k = $0
        }
        return "\($0) is a good number."
      }
    )

    viewModel.incrementButtonTapped()
    XCTAssertEqual(viewModel.count, 1)


    let task = Task {
      await viewModel.getFact()
    }
    while k == nil {
      await Task.yield()
    }
    XCTAssertEqual(viewModel.isLoading, true)
    k!.resume()
    await task.value
    XCTAssertEqual(viewModel.fact, "1 is a good number.")
    XCTAssertEqual(viewModel.isLoading, false)
  }

  func testVanilla_Cancellation() async {
    var k: CheckedContinuation<Void, Never>? = nil

    let viewModel = PullToRefreshViewModel(
      fetch: {
        await withCheckedContinuation {
          k = $0
        }
        return "\($0) is a good number."
      }
    )

    viewModel.incrementButtonTapped()
    XCTAssertEqual(viewModel.count, 1)

    Task {
      await viewModel.getFact()
    }
    while k == nil {
      await Task.yield()
    }
    XCTAssertEqual(viewModel.isLoading, true)
    viewModel.cancelButtonTapped()
    XCTAssertNil(viewModel.fact)
    XCTAssertEqual(viewModel.isLoading, false)
  }
}