Medium blogpost snippet

SecureStorageTests.swift

func test_givenUnlockedSecureStorage_whenSavingValue_itCanBeLaterRead() {
    let storage = SecureStorage<String>()
    let unlockExpectation = self.expectation(description: "secure storage is unlocked")
    let saveExpectation = self.expectation(description: "value is saved")
    let readExpectation = self.expectation(description: "value is read")

    storage.unlock { (unlocked) in
        XCTAssertTrue(unlocked)
        unlockExpectation.fulfill()
    }

    wait(for: [unlockExpectation], timeout: 1)

    storage.save("secret") {
        saveExpectation.fulfill()
    }

    wait(for: [saveExpectation], timeout: 1)

    storage.read { value in
        XCTAssertEqual(value, "secret")
        readExpectation.fulfill()
    }

    wait(for: [readExpectation], timeout: 1)
}