migration

Replace the deprecated textScaleFactor on MediaQueryData, Text, RichText and TextPainter with TextScaler. What dart fix rewrites (3 of 9 call sites in our sample), why its output can quietly undo Android 14 nonlinear font scaling, how to cap text size with clamp and withClampedTextScaling, and the equality and test gotchas. Measured on Flutter 3.44.8 with Dart 3.12.2.

A tested migration from FluentAssertions 8.11 to AwesomeAssertions 9.6 on .NET 10: the two-hop path through AwesomeAssertions 8.2, the License.Accepted compile error, the namespace rename, companion packages, and the silent DLL clash that can put the Xceed-licensed assembly back in your test run.

A tested migration of an xUnit v3 test project on .NET 10 from Moq 4.21.0 to NSubstitute 6.2.0: the full API mapping table, out parameters, events, protected members, partial mocks, and four gotchas that a mechanical find-and-replace walks straight into.

A tested, file-by-file conversion of a Flutter app's settings.gradle, build.gradle and app/build.gradle to Kotlin DSL on Flutter 3.44.8, AGP 9.0.1 and Gradle 9.1.0, with the real compiler errors each naive rename produces and the exact fix for signing configs, flavors, minifyEnabled and kotlinOptions.

Moving an agent from claude-sonnet-4-6 or claude-opus-4-7 to claude-sonnet-5-5 or claude-opus-5-5 is not just a model ID swap. Thinking is always on, thinking-off and forced tool_choice now return 400, the effort defaults moved, Sonnet counts about 30% more tokens, and Claude Code ignores your old effortLevel on Opus 5.5. Here is the full checklist with before/after code.

Replace the deprecated Color.withOpacity, opacity, value, red, green, blue and alpha with withValues, .a/.r/.g/.b and toARGB32. What dart fix rewrites for you, the four getters it leaves behind, why exact color assertions and Map<Color, T> lookups break after the swap, and how withOpacity silently drops Display P3. Measured on Flutter 3.44.8 with Dart 3.12.2.

Rename MaterialState, MaterialStateProperty, MaterialStateColor and the rest of the family to their WidgetState equivalents. What dart fix rewrites, the input border subclasses it cannot touch, why a fromMap with & or | keys cannot be const, and how fromMap throws where resolveWith quietly fell back. Measured on Flutter 3.44.8 with Dart 3.12.2.

Replace hand-rolled WidgetsBindingObserver lifecycle code with AppLifecycleListener: the callback mapping, the state machine it enforces, the new hidden state that breaks exhaustive switches, desktop exit requests, and the test that suddenly asserts. Tested on Flutter 3.44.8 with 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.

Upgrading a Blazor Web App whose pages live in a Razor class library or a .Client project from .NET 8 to .NET 10: what stays the same (both AdditionalAssemblies registrations), and the four things that break, from a 404 on blazor.web.js in thin hosts to NotFoundPage pages that render blank. Measured on ASP.NET Core 8.0.32 and 10.0.10.