What problem does it solve? Static calls like DateTime.UtcNow and File.ReadAllText make .NET code untestable and hard to control in unit tests. This Skill performs codemod-style bulk replacement of those static call sites with injected abstractions such as TimeProvider or IFileSystem, including constructor injection and test updates, within a bounded file, project, or namespace scope. ## Core Features & Use Cases - Mechanical call-site replacement: Maps static calls (DateTime.Now/UtcNow, File.*, Directory.Exists, Environment, Console, Process) to their wrapper equivalents while preserving DateTimeKind and surrounding code structure. - Constructor injection and ambient seams: Adds constructor or primary-constructor parameters following existing naming conventions, and applies an ambient static seam pattern for static classes that cannot receive injection. - Test migration: Updates affected unit tests to use FakeTimeProvider, MockFileSystem, or mocks, and verifies the result with dotnet build. - Use Case: Migrate DateTime.UtcNow to TimeProvider across one service project, adding constructor injection to affected classes and switching their tests to FakeTimeProvider, then confirm the build passes. ## Quick Start Replace all DateTime.UtcNow calls in the Services project with TimeProvider, add constructor injection, and update the unit tests to use FakeTimeProvider.
