S SimplicityTools Measure complexity before it measures your team.

Analyzer

SF0002

Flags PackageReference entries that contribute no detected symbol usage in C# source so dependency cost does not accumulate silently.

Diagnostic contract

Unused packages add restore time, transitive risk, and maintenance cost. The cleanest dependency is the one you do not carry.

SF0002 SimplicityFirst.HalfRule Warning Code fix available
When it fires

A PackageReference maps to assemblies in the compilation, but no symbols from those assemblies are used in countable C# source files.

Rule message

PackageReference {0} has no detected symbol usage in C# source. Remove the dependency or justify it with source usage.

Help link target

/analyzers/sf0002/

When it fires

These are the concrete cases to look for in code review and IDE diagnostics.

  • The analyzer reads PackageReference items from the project file and maps them to referenced assemblies.
  • It scans countable source files for used symbols and treats packages with zero symbol usage as unused.
  • The rule reports at compilation end so it can evaluate the full project graph instead of guessing per syntax node.

Bad / better example

Use these examples to explain the rule, not just silence it.

Before

<ItemGroup>
  <PackageReference Include="Serilog" Version="4.0.0" />
  <PackageReference Include="Microsoft.Extensions.Logging" Version="9.0.0" />
</ItemGroup>

If no Serilog symbols are used in the project, this reference is dead weight.

After

<ItemGroup>
  <PackageReference Include="Microsoft.Extensions.Logging" Version="9.0.0" />
</ItemGroup>

The project keeps only the package that contributes real code usage.

Code fix

The code fix removes the targeted PackageReference node from the project file without rewriting unrelated XML.

  • Run a normal build after applying the fix so any non-symbol usage contracts become obvious.
  • Analyzer-only, build-only, or source-generator dependencies may need a deliberate justification instead of a blind delete.
  • This is the second in-repo diagnostic with an automatic code fix.

Source and follow-up links

Use these links when you need to validate behavior against the source or connect the docs back to project tracking.

Source

Analyzer implementation

UnusedDependencyAnalyzer.cs

 Code fix

Implementation details

UnusedDependencyCodeFixProvider.cs

 Tracking

Issue #55

Documentation tracker for the analyzer pages and related integration guidance.

 Guide

csproj reference

Keep analyzer installation isolated while pruning package sprawl in application projects.

 Filter

HalfRule

Unused dependencies are a direct HalfRule smell.