Swift Testing

Expressive tests written with macros, made for Swift from the start.

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Introduced

2024

WWDC24

Kind

Framework

Runs on

Xcode 16 or later

Get it from

Included with Xcode

iOS

iPadOS

Mac Catalyst

macOS

tvOS

visionOS

watchOS

Overview

Mark a function with @Test and check results with #expect. When something fails, you see the actual values involved, not just “assertion failed”.

Tests can take arguments to run once per input, carry tags and traits, and run in parallel by default. It lives alongside XCTest, so you can adopt it one file at a time.

@Test

Any function can be a test: no subclass, no test prefix, async and throwing allowed.

#expect and #require

One macro for checks that captures the values involved when something fails.

Parameterized tests

Pass a collection of arguments and the same test runs once per input.

Traits and tags

Disable, time-limit, serialize or group tests with a short annotation.

PriceTests.swift

import Testing

@Test("Discounts never go below zero",
      arguments: [0, 10, 50, 100])
func discount(percent: Int) {
    let price = Price(amount: 20)
    let result = price.applying(discount: percent)
    #expect(result.amount >= 0)
}

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