How do I use classes from my module in XCTestCase?

Question

I am trying to test this class (Swiftris/Swifteris/Array2D.swift):

class Array2D<T> {

    let rows: Int
    let columns: Int

    var array: Array<T?>

    init(rows: Int, columns: Int) {
        self.rows = rows
        self.columns = columns

        array = Array<T?>(count:rows * columns, repeatedValue: nil)
    }

    subscript(column: Int, row: Int) -> T? {
        get {
            return array[(row * columns) + column]
        }
        set {
            array[(row * columns) + column] = newValue
        }
    }
}

With this simple test (Swiftris/SwiftrisTests/Array2DTest.swift):

import UIKit
import XCTest

class Array2DTest: XCTestCase {

    override func setUp() {
        super.setUp()
        // Put setup code here. This method is called before the invocation of each test method in the class.
    }

    func testHasRows() {
        var array: Array2D = Array2D(rows: 10, columns: 15)
        XCTAssertEqual(array.rows, 20, "an Array2D instance should have the correct number of rows")
    }
}

It unexplainably fails to resolve Array2D:

Swifteris/SwifterisTests/Array2DTest.swift:12:20: Use of undeclared type 'Array2D'

Do I need to import my own module into my tests? This is pretty puzzling since I did the exact same thin in another project and had no trouble resolving classes under test.

I´m running the tests though Xcode - in case this matters. – max Nov 01 '14 at 14:28 — max, Nov 01 '14 at 14:28

score 8 · Accepted Answer · edited May 23 '17 at 12:20

You have 2 options.

Add `Array2D.swift` to `SwifterisTests` Target Membership

It's very simple

screenshot

Import `Swifteris` to `Array2DTest.swift`

Basically this method is recommended, but it's relatively annoying.

At first, you have to declare all testable classes/methods/properties as public:

Array2D.swift:

public class Array2D<T> {

    public let rows: Int
    public let columns: Int

    private var array: Array<T?>

    public init(rows: Int, columns: Int) {
        self.rows = rows
        self.columns = columns

        array = Array<T?>(count:rows * columns, repeatedValue: nil)
    }

    public subscript(column: Int, row: Int) -> T? {
        get {
            return array[(row * columns) + column]
        }
        set {
            array[(row * columns) + column] = newValue
        }
    }
}

Then, import main module Swifteris to test module SwifterisTests

import XCTest
import Swifteris

// Here Array2D is avaiable.

More discussion on this Q/A: Swift, access modifiers and unit testing

Any idea why doing `Array2D(rows: 9, columns: 10)` gives me `Argument for generic parameter 'T' could not be inferred`? — max, Nov 02 '14 at 11:25
Because you didn't provide any information about `T`. For example , `var array = Array2D(rows: 9, columns: 10)` would be OK, in that case `T` will be bound to `String`. — rintaro, Nov 02 '14 at 11:47

How do I use classes from my module in XCTestCase?

1 Answers1

Add Array2D.swift to SwifterisTests Target Membership

Import Swifteris to Array2DTest.swift

Add `Array2D.swift` to `SwifterisTests` Target Membership

Import `Swifteris` to `Array2DTest.swift`