Flexible XCTest assertions in Swift.
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This is a Swift µframework providing simple, flexible assertions for XCTest in Swift.

Requires Swift 1.2 (Xcode 6.3)


Assert that an optional array is equal to another array:

let array: [Int]? = [1, 2, 3]
assert(maybeAnArray(), ==, [1, 2, 3])

If you tried to use XCTAssertEqual, you’d have to unwrap the optional first:

XCTAssertEqual(array, [1, 2, 3])
// => error: value of optional type '[Int]?' not unwrapped; did you mean to use '!' or '?'?

This works great with optionals of other types, too:

let string: String? = "hello"
assert(string, ==, "hello")

Here, too, XCTAssertEqual would force you to unwrap the optional:

XCTAssertEqual(string, "hello")
// => error: cannot find an overload for 'XCTAssertEqual' that accepts an argument list of type '(String?, String)'

You can also pass in methods:

let set: Set<Int>? = Set([1, 2, 3])
assert(set, Set.contains, 3)

And you can use the predicate form for any other test you might want to write:

let string: String? = ""
assert(string, { $0.isEmpty })

These last two are approximately equivalent to using Swift’s optional chaining, but you might find them handy.


  1. Add this repo as a submodule in e.g. External/Assertions:

     git submodule add https://github.com/robrix/Assertions.git External/Assertions
  2. Drag Assertions.xcodeproj into your .xcworkspace/.xcodeproj.

  3. Add Assertions.framework to your test target’s Link Binary With Libraries build phase.