CH

check-rust-coverage

Detects and lists specific lines of Rust code not covered by existing tests.

Install

mkdir -p .claude/skills/check-rust-coverage && curl -L -o skill.zip "https://agentskills.codes/api/skills/download/1049" && unzip -o skill.zip -d .claude/skills/check-rust-coverage && rm skill.zip

Installs to .claude/skills/check-rust-coverage

Activation

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Check which Rust lines are not covered by Rust tests. Use this when you developed new Rust code and want to ensure it is tested.
128 chars✓ has a “when” trigger
Beginner

Key capabilities

  • Run coverage analysis on Rust crates
  • Identify untested lines of code
  • Output uncovered line numbers

How it works

It executes cargo llvm-cov to generate coverage data and filters the JSON output to display lines with zero hits.

Inputs & outputs

You give it
Path to a Rust crate
You get back
List of uncovered lines per file

When to use check-rust-coverage

  • Check test coverage for new crate features
  • Identify untested edge cases in source code
  • Audit project test maturity

About this skill

Check Rust Coverage

Determine which Rust lines are not covered by Rust tests.

Arguments

  • <path>: Path to a Rust crate.
  • <path 1> <path 2>: Multiple crate paths.

If a path doesn't include src/, assume it to be in the src/redisearch_rs directory. E.g. numeric_range_tree becomes src/redisearch_rs/numeric_range_tree. If a path points to a directory, consider all Rust crates in that directory.

Instructions

Run

cargo llvm-cov test --manifest-path <crate_directory>/Cargo.toml --quiet --json 2>/dev/null | jq -r '"Uncovered Lines:",
(.data[0].files[] |
  select(.summary.lines.percent < 100) |
  .filename as $f |
  [.segments[] | select(.[2] == 0 and .[4] == true) | .[0]] |
  unique |
  if length > 0 then "\($f): \(join(", "))" else empty end
)'

to get the list of uncovered lines for each file in the target crate.

When not to use it

  • When the project is not a Rust crate
  • When tests are not configured for the target

Prerequisites

cargo-llvm-covjq

Limitations

  • Requires cargo-llvm-cov installation
  • Only works for Rust projects

How it compares

It provides a direct, automated path to identifying specific untested lines rather than relying on manual coverage report inspection.

Compared to similar skills

check-rust-coverage side by side with the closest alternatives in the catalog.

SkillInstallsUpdatedSafetyDifficulty
check-rust-coverage (this skill)55moReviewBeginner
rust-tests-guidelines75moNo flagsBeginner
check-code-quality128dReviewAdvanced
lint12moReviewIntermediate

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