--- title: What testing issue showed up with @Observable? | daily.dev description: Tests were passing but bugs reached production because @Observable updates lazily, causing synchronous test expectations to miss intermediate states. The... canonical: https://daily.dev/posts/what-testing-issue-showed-up-with-observable--ty6y7dj3h twitter:card: summary_large_image twitter:site: @dailydotdev og:type: website og:site_name: daily.dev og:title: What testing issue showed up with @Observable? | daily.dev og:description: Tests were passing but bugs reached production because @Observable updates lazily, causing synchronous test expectations to miss intermediate states. The... og:url: https://daily.dev/posts/what-testing-issue-showed-up-with-observable--ty6y7dj3h og:image: https://api.daily.dev/og/posts/Ty6y7DJ3H.png og:image:alt: What testing issue showed up with @Observable? 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. # What testing issue showed up with @Observable? **[Rebeloper](https://daily.dev/sources/rebeloper)** · 1 min read · 0 upvotes · 0 comments ## Summary Tests were passing but bugs reached production because @Observable updates lazily, causing synchronous test expectations to miss intermediate states. The solution involved asserting sequences and waiting for stable snapshots, which slowed tests but increased confidence in catching real issues. ## Full article daily.dev links to this article rather than hosting it. Read it at the original source: ## Similar posts on daily.dev - [Beta Preview: DebugSnapshots](https://daily.dev/posts/beta-preview-debugsnapshots-bzx1spcku) · Point-Free Pointers · 0 upvotes · 0 comments --- Tags: [#testing](https://daily.dev/tags/testing), [#swift](https://daily.dev/tags/swift), [#swiftui](https://daily.dev/tags/swiftui) [View this post on daily.dev](https://daily.dev/posts/what-testing-issue-showed-up-with-observable--ty6y7dj3h) ```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":"What testing issue showed up with @Observable?","url":"https://daily.dev/posts/what-testing-issue-showed-up-with-observable--ty6y7dj3h","mainEntityOfPage":{"@type":"WebPage","@id":"https://daily.dev/posts/what-testing-issue-showed-up-with-observable--ty6y7dj3h"},"datePublished":"2026-02-12T11:10:38.040Z","dateModified":"2026-02-12T11:10:54.582Z","description":"Tests were passing but bugs reached production because @Observable updates lazily, causing synchronous test expectations to miss intermediate states. 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