.NET Platform

Correct and improve existing MSTest tests using APIs supported by the installed version. Refine assertions and failure messages, update data-driven tests, fix setup and cleanup, and address MSTest diagnostics while preserving the project's established conventions.

• Making assertion failures easier to understand
• Correcting expected and actual argument order
• Improving existing data-driven tests

Find source files with no matching test references by parsing code without building or running tests. Produces a source-to-test map and suggested test locations, helping plan test additions across supported programming languages.

• List source files with no matching tests
• Choose locations for new test files
• Check source-to-test pairing after adding tests

Create, modify, debug, and review Windows Forms applications while preserving their editable layouts in Visual Studio Designer. Covers resizing, data binding, asynchronous UI behavior, and checks that distinguish successful builds from actual screen and designer verification.

• Fixing forms that fail to open in Visual Studio Designer
• Resolving clipped controls after resizing or DPI changes
• Repairing bound lists that do not refresh

Apply the System.Text.Json APIs introduced in .NET 11 to produce PascalCase JSON names and retrieve typed serialization metadata, the information used to convert objects. Create runnable examples and check metadata availability without exception-based probing.

• Produce PascalCase JSON property names
• Convert dictionary keys to PascalCase
• Retrieve typed serialization metadata without casts

Classify existing tests with standard tags for success cases, errors, boundaries, and other behaviors. Get a per-test mapping and distribution summary, or apply tags using supported framework syntax and verify compilation and test discovery.

• Comparing success-case and error-case test counts
• Adding standard tags to existing tests
• Reviewing the mix of boundary and integration tests

Move NuGet package versions from individual .NET projects into a shared management file. The skill audits version conflicts, preserves project conditions, validates builds before and after conversion, and produces comparison files and a migration report.

• Adopting central NuGet package version management
• Aligning inconsistent package versions across projects
• Moving shared version properties into central declarations

Fill in related settings for .NET project creation while preserving explicit user choices. Produce a table explaining each choice and an exact dotnet new command, checking available options against the selected template’s help.

• Choosing a target framework for Native AOT
• Reviewing HTTPS settings when authentication is enabled
• Organizing API options when controllers are selected

Upgrade MSTest v3 test projects to v4 by updating packages, adapting code to changed APIs, and checking execution behavior. It also helps resolve build errors and problems finding tests in CI after an upgrade.

• Upgrading an MSTest v3 project to v4
• Fixing compilation errors after an upgrade
• Updating custom TestMethodAttribute implementations

Find language-specific guidance files for a code-testing pipeline. This reference catalog points agents to build and test commands, mocking patterns, common errors, and selected workflow examples across languages including .NET, Python, TypeScript, Go, and Java.

• Finding test guidance for a project's programming language
• Locating build commands and test framework guidance
• Finding mocking patterns and common error references

Calculate change risk for a specific .NET method, class, or file by combining code complexity with measured test coverage. Get ranked results and recommendations on where to add tests or simplify logic.

• Calculate risk scores for a specific method
• Prioritize tests within a class
• Find complex, undertested methods in a file

Refactor C#/.NET code through renaming, extraction, consolidation, and other structural changes while preserving behavior. Check compatibility beyond code references, including public APIs and serialized names, then validate with builds and relevant tests.

• Rename C# members and update their references
• Extract shared logic from duplicate code
• Reorganize code while preserving public API compatibility

Install a .NET SDK, the tools used to build .NET projects, inside a project folder. Configure version selection and shared setup scripts to test previews or reproduce team and CI environments without changing the system installation.

• Trying a .NET preview without changing the system installation
• Pinning a project to a specific SDK version
• Creating repeatable setup scripts for teams and CI

Migrate legacy .NET project files to SDK-style format, reducing repetitive XML and explicit file lists. Convert package references, move assembly metadata into project settings, and consolidate shared build and package settings across multiple projects.

• Convert legacy .csproj or .vbproj files to SDK-style
• Migrate packages.config to PackageReference
• Replace AssemblyInfo.cs with generated assembly metadata

Upgrade an existing .NET 8 project to .NET 9 by addressing build errors and compatibility changes. Update related packages, containers, and build pipelines, then verify the migration with clean builds and tests.

• Upgrading a project from net8.0 to net9.0
• Resolving new build errors and warnings after upgrading
• Reviewing ASP.NET Core and EF Core behavior changes

Turn .NET runtime addresses in Android crash reports into function names, source files, and line numbers. The skill extracts build identifiers, downloads matching debug symbols, and uses llvm-symbolizer to produce a readable backtrace.

• Triaging native crashes in .NET MAUI or Mono Android apps
• Resolving libmonosgen-2.0.so and libcoreclr.so frames
• Investigating runtime-related SIGABRT or SIGSEGV crashes

Investigate MSBuild failures caused by projects or build configurations writing to the same output folders. Compare build logs, output paths, and project settings to identify collisions behind overwritten files, restore errors, or failures that disappear on retry.

• Investigate file access errors during parallel builds
• Find shared intermediate folders causing NuGet restore errors
• Check output paths when building for multiple frameworks

Review and fix how MSBuild manages lists of files and their metadata, or attached information. Check Include, Remove, Update, filtering, path transformations, duplicates, and execution grouping to clarify whether item operations behave as intended.

• Reviewing Include, Remove, and Update usage
• Investigating duplicate or overlapping file entries
• Checking metadata-based execution grouping

Choose diagnostic tools and collect performance traces for production .NET problems such as high CPU usage, memory growth, or slow requests. Get environment-specific collection commands and guidance on which tools to use for later analysis.

• Collecting traces during high CPU usage or slow requests
• Choosing diagnostic tools for Windows or Linux
• Collecting diagnostics from containers or Kubernetes

Fix Blazor issues during prerendering, when the server sends initial HTML before interactive features load. Preserve component state to avoid repeated data requests and flicker, handle unavailable services, and configure prerendering or page routing where needed.

• Fixing duplicate data requests on initial page loads
• Reducing flicker when a page becomes interactive
• Handling client services unavailable during prerendering

Review database access built with Entity Framework Core to find slow queries, excessive database calls, memory costs, and correctness issues. It traces application code and uses available SQL logs or execution plans to support targeted fixes.

• Reviewing slow EF Core queries and excessive database calls
• Investigating memory use in imports and background jobs
• Checking search filters, pagination, and index coverage

Investigate .NET app crashes on Apple platforms by converting runtime addresses in .ips logs into function names, source files, and line numbers. It locates matching debug symbols and supports retrieving logs from connected iOS devices.

• Investigating .NET MAUI or Mono crashes on Apple platforms
• Resolving runtime addresses to source files and line numbers
• Retrieving crash logs from a connected iPhone

Analyze CLR activation logs to explain how .NET Framework selects and loads its runtime, the software that executes managed code. Diagnose loading failures, unexpected version choices, installation dialogs, and conflicting activation paths within a process.

• Investigating failures to load the .NET Framework runtime
• Explaining why an unexpected CLR version was selected
• Tracing .NET 3.5 installation dialogs or their absence

Configure automatic crash dumps, files that capture application state, or collect one from a running modern .NET process. Follow platform and runtime guidance for desktop, server, Docker, or Kubernetes environments and receive the saved file location.

• Enabling automatic dump collection when a .NET app crashes
• Capturing a dump from a running .NET process
• Setting up dump collection in Docker or Kubernetes

Design, configure, run, and review BenchmarkDotNet measurements of small .NET operations. Compare implementations, runtime versions, or input sizes, while controlling setup work, measurement errors, and case counts so results support a concrete performance decision.

• Compare the performance of alternative implementations
• Reproduce a reported performance problem
• Measure performance before and after a code change