--- title: Swift Testing explained with code examples | daily.dev description: Swift Testing is the modern macro-based testing framework that replaces XCTest as the default for new Swift projects, using @Test, #expect, and #require... canonical: https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5 twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: Swift Testing explained with code examples | daily.dev og:description: Swift Testing is the modern macro-based testing framework that replaces XCTest as the default for new Swift projects, using @Test, #expect, and #require... og:url: https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5 og:image: https://api.daily.dev/og/posts/pGXKVbvK5.png og:image:alt: Swift Testing explained with code examples og:image:width: 1200 og:image:height: 630 og:locale: en --- > ## Documentation Index > Fetch the complete documentation index at: https://daily.dev/llms.txt > Use this file to discover all available pages before exploring further. # Swift Testing explained with code examples **[SwiftLee](https://daily.dev/sources/avanderlee)** · 9 min read · 1 upvotes · 0 comments ## Summary Swift Testing is the modern macro-based testing framework that replaces XCTest as the default for new Swift projects, using @Test, #expect, and #require instead of dozens of assertion methods. The guide walks through writing and organizing tests with structs and nested types, parameterized tests to reduce boilerplate, exit tests (available since Swift 6.2 with Xcode 26) for testing fatalError/precondition code paths, attaching values like CSV data or images to test reports, and migrating incrementally from XCTest since UI automation and performance tests still require the older framework. It also mentions an AI Agent Skill the author built to teach coding agents these Swift Testing conventions. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Questions this post answers ### What is the difference between Swift Testing's @Test macro and XCTest's test method naming convention? Swift Testing replaces the requirement to prefix test methods with 'test' by using an explicit @Test macro instead. Tests can even be defined as free functions outside of a class, unlike XCTest which requires subclassing XCTestCase and naming methods with a 'test' prefix for the runner to discover them. _Developers comparing Swift Testing and XCTest conventions can track framework changes like this on daily.dev._ ### How do I test that a precondition or fatalError call actually crashes my Swift code? Swift Testing added exit tests, which run the test body in a child process and validate how that process exits, using syntax like #expect(processExitsWith: .failure). This requires Swift 6.2 and Xcode 26 or later, works on macOS and Linux but not iOS, and any captured values must conform to both Sendable and Codable since they cross into the child process. _Developers adopting exit tests for crash paths can follow Swift testing updates like this on daily.dev._ ### Can XCTest and Swift Testing coexist in the same project during migration? Yes, both frameworks can run in the same test target, allowing incremental migration. UI automation tests using XCUIApplication and performance tests using XCTMetric still require XCTest, so a typical migration path converts assertions first, then reorganizes test suites, and finally introduces parameterized tests where repetition is spotted. _Teams planning an XCTest to Swift Testing migration can keep up with guidance like this on daily.dev._ ## Similar posts on daily.dev - [Swift Testing — Hopes Entrusted to the Future](https://daily.dev/posts/swift-testing-hopes-entrusted-to-the-future-mjeviiebe) · Medium · 0 upvotes · 0 comments - [Swift Testing Agent Skill: Write high quality tests with AI](https://daily.dev/posts/swift-testing-agent-skill-write-high-quality-tests-with-ai-tbmj7iytj) · SwiftLee · 0 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#ios](https://daily.dev/tags/ios), [#swift](https://daily.dev/tags/swift) [View this post on daily.dev](https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5) ```json {"@context":"https://schema.org","@graph":[{"@type":"Organization","@id":"https://daily.dev/#organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180},"sameAs":["https://twitter.com/dailydotdev","https://github.com/dailydotdev","https://www.linkedin.com/company/daily-dev-ltd"]},{"@type":"WebSite","@id":"https://daily.dev/#website","url":"https://daily.dev","name":"daily.dev","publisher":{"@id":"https://daily.dev/#organization"},"potentialAction":{"@type":"SearchAction","target":{"@type":"EntryPoint","urlTemplate":"https://daily.dev/search?q={search_term_string}"},"query-input":"required name=search_term_string"}}]} {"@context":"https://schema.org","@type":"TechArticle","headline":"Swift Testing explained with code examples","url":"https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5"},"datePublished":"2026-08-17T08:57:09.693Z","dateModified":"2026-09-13T21:22:58.915Z","description":"Swift Testing is the modern macro-based testing framework that replaces XCTest as the default for new Swift projects, using @Test, #expect, and #require...","image":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2b606e574e48c4c4b0314f03b64603c9?_a=AQAEuop","thumbnailUrl":"https://media.daily.dev/image/upload/f_auto,q_auto/v1/posts/2b606e574e48c4c4b0314f03b64603c9?_a=AQAEuop","isAccessibleForFree":true,"articleSection":"SwiftLee","inLanguage":"en","publisher":{"@type":"Organization","name":"daily.dev","url":"https://daily.dev","logo":{"@type":"ImageObject","url":"https://daily.dev/apple-touch-icon.png","width":180,"height":180}},"author":{"@type":"Organization","name":"SwiftLee","logo":"https://media.daily.dev/image/upload/t_logo,f_auto/v1/logos/407bdbf78c69402985a468cb336a76ae","url":"https://daily.dev/sources/avanderlee"},"commentCount":0,"discussionUrl":"https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5","interactionStatistic":[{"@type":"InteractionCounter","interactionType":{"@type":"LikeAction"},"userInteractionCount":1},{"@type":"InteractionCounter","interactionType":{"@type":"CommentAction"},"userInteractionCount":0}],"keywords":"testing,ios,swift","timeRequired":"PT9M"} {"@context":"https://schema.org","@type":"BreadcrumbList","itemListElement":[{"@type":"ListItem","position":1,"name":"Home","item":"https://daily.dev"},{"@type":"ListItem","position":2,"name":"SwiftLee","item":"https://daily.dev/sources/avanderlee"},{"@type":"ListItem","position":3,"name":"Swift Testing explained with code examples"}]} {"@context":"https://schema.org","@type":"FAQPage","@id":"https://daily.dev/posts/swift-testing-explained-with-code-examples-pgxkvbvk5#faq","mainEntity":[{"@type":"Question","name":"What is the difference between Swift Testing's @Test macro and XCTest's test method naming convention?","acceptedAnswer":{"@type":"Answer","text":"Swift Testing replaces the requirement to prefix test methods with 'test' by using an explicit @Test macro instead. 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