assertMemoryDeallocation

XCTestCase+MemoryDeallocation.swift

import XCTest

public extension XCTestCase {
    /// This is a method to determine that an instance gets deallocated from memory correctly; ie: no memory leaks 😄.
    /// It leverages the `addTeardownBlock` method on `XCTest`:
    /// `* Teardown blocks are executed after the current test method has returned but before tearDown is invoked.`
    func assertMemoryDeallocation(
        in instance: AnyObject,
        file: StaticString = #filePath,
        line: UInt = #line
    ) {
        addTeardownBlock { [weak instance] in
            XCTAssertNil(
                instance,
                "Instance should have been deallocated. Potential memory leak!",
                file: file,
                line: line
            )
        }
    }
}