dart

A broadcast StreamController drops every event that fired before you subscribed. Here is a dependency-free BehaviorSubject replacement built on Stream.multi, a replayLatest() extension for existing streams, the async* shortcut that silently loses events, and the StreamBuilder initialData detail, all verified on Dart 3.12.2.

A one-time, crash-safe import of existing Hive boxes into a drift SQLite database on the user's device: schema design, the import function, idempotency, deleting the boxes, and the two gotchas that silently corrupt data (DateTime precision and class-name collisions). Tested on Flutter 3.44.8 with hive_ce 2.22.0 and drift 2.35.2.

WillPopScope and onPopInvoked are deprecated, and predictive back on Android 14+ ignores them. How to move each onWillPop pattern to PopScope.canPop and onPopInvokedWithResult, the confirm-dialog loop you have to guard against, the PopScope<T> type crash, and what dart fix will not do for you. Tested on Flutter 3.44.8.

The Flutter SDK pins versions of meta, vector_math, test_api and matcher, so every SDK change re-resolves your lockfile, and flutter upgrade runs pub upgrade on the project you stand in. Pin one Flutter version per repo and enforce the lockfile in CI.

Drive NavigationBar.selectedIndex from StatefulNavigationShell.currentIndex, never from a setState field or a copy made in initState. Measured on Flutter 3.44.8 and go_router 18.0.2: which patterns drift on deep links, context.go and cross-branch pushes, why location-based indexes lie, and how to react to tab changes with didUpdateWidget.

Genkit Dart 1.0.0 freezes the API, moves HTTP serving into core with GenkitRouter, and changes the streamed error frame. Shipped Flutter apps on a 0.17 client need sendLegacyErrorFrame.

A build mode (debug, profile, release) decides how Flutter compiles your Dart code. A flavor (dev, staging, prod) is a native build variant you define in Gradle and Xcode that decides which app you ship. They are independent axes: 2 flavors times 3 modes is 6 builds. Verified on Flutter 3.44.8 with AGP 9.0.1, source checked against 3.47.7.

Flutter moved PageTransitionsBuilder and two built-in builders into the widgets layer and CupertinoPageTransitionsBuilder out of Material. What actually breaks (one import, with a misleading 'Not a constant expression' error), what dart fix does and gets wrong for material_ui projects, and how to rewrite custom builders and routes so they no longer depend on Material at all.

A widget asked for height: double.infinity inside a parent with no height limit, like a Column or ListView. Use Expanded, a finite height, LimitedBox, or SliverFillRemaining instead.

The official google_mobile_ads sample renders nothing until onAdLoaded, so your content jumps by 150 dp seconds after the screen appears. Ask for the anchored adaptive size first, reserve it with a SizedBox, persist the height across launches, and only then load the ad. Measured on Flutter 3.44.8 with google_mobile_ads 9.1.0.