What problem does it solve? Static calls like DateTime.UtcNow and File.ReadAllText make C# code untestable and tightly coupled. This Skill performs codemod-style bulk replacement of those call sites with injected abstractions such as TimeProvider or IFileSystem, including constructor injection and test updates, within a bounded scope. ## Core Features & Use Cases - Bulk call-site replacement: Migrates DateTime.Now/UtcNow to TimeProvider, File.* to IFileSystem, and similar statics across a file, project, or namespace. - Constructor injection handling: Adds the new dependency via traditional or primary constructors, and applies an ambient-context seam for static classes that cannot receive injection. - Test updates and verification: Updates unit tests to use FakeTimeProvider or MockFileSystem, verifies DI registration, and runs dotnet build to confirm the migration compiles. - Use Case: You want to make an OrderProcessor class testable. Run the migration on its project to replace every DateTime.UtcNow with TimeProvider.GetUtcNow(), inject TimeProvider into the constructor, and update its tests to use FakeTimeProvider. ## Quick Start Migrate all DateTime.UtcNow call sites in the Services project to TimeProvider, add constructor injection, and update the affected unit tests to use FakeTimeProvider.
