swift-testing

# Swift Testing

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Swift Testing is a package with expressive and intuitive APIs that make testing
your Swift code a breeze.

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## Feature overview

### Clear, expressive API

Swift Testing has a clear and expressive API built using macros, so you can
declare complex behaviors with a small amount of code. The `#expect` API uses
Swift expressions and operators, and captures the evaluated values so you can
quickly understand what went wrong when a test fails.

```swift
import Testing

@Test func helloWorld() {
  let greeting = "Hello, world!"
  #expect(greeting == "Hello") // Expectation failed: (greeting → "Hello, world!") == "Hello"
}
```

### Custom test behaviors

You can customize the behavior of tests or test suites using traits specified in
your code. Traits can describe the runtime conditions for a test, like which
device a test should run on, or limit a test to certain operating system
versions. Traits can also help you use continuous integration effectively by
specifying execution time limits for your tests.

```swift
@Test(.enabled(if: AppFeatures.isCommentingEnabled))
func videoCommenting() async throws {
    let video = try #require(await videoLibrary.video(named: "A Beach"))
    #expect(video.comments.contains("So picturesque!"))
}
```

### Easy and flexible organization

Swift Testing provides many ways to keep your tests organized. Structure
related tests using a hierarchy of groups and subgroups. Apply tags to flexibly
manage, edit, and run tests with common characteristics across your test suite,
like tests that target a specific device or use a specific module. You can also
give tests a descriptive name so you know what they’re doing at a glance.

```swift
@Test(.tags(.metadata))
func `Check video metadata`() {
    let video = Video(fileName: "By Lake Tahoe.mov")
    let expectedMetadata = Metadata(duration: .seconds(90), filmingLocation: "California")
    #expect(video.metadata == expectedMetadata)
}
```

### Scalable coverage and execution

Parameterized tests let you write less code by running the same test over many
different inputs. And all tests integrate seamlessly with Swift Concurrency and
run in paral