Coverage Report Skill

This skill generates a comprehensive code coverage report for the Pinhole project using Rust's built-in LLVM coverage tools.

What This Skill Does

•Cleans up any existing coverage files
•Runs all tests with coverage instrumentation
•Merges coverage data from all test runs
•
Generates and displays a coverage report showing:
- •Overall coverage percentage
- •Per-file coverage statistics
- •Functions and lines covered/missed
•Cleans up temporary coverage files

Implementation

Execute these steps in order:

Step 1: Clean existing coverage files

bash

cd /Users/michael/dev/pinhole
find . -name "*.profraw" -o -name "*.profdata" | xargs rm -f 2>/dev/null || true
echo "Cleaned up existing coverage files"

Step 2: Run tests with coverage instrumentation

bash

cd /Users/michael/dev/pinhole
RUSTFLAGS="-C instrument-coverage" LLVM_PROFILE_FILE="pinhole-%p-%m.profraw" cargo test --workspace 2>&1

Important: This step compiles all code with instrumentation and runs 113 tests. It may take 60-120 seconds. If it times out, run it in the background using run_in_background: true.

Step 3: Find LLVM tools

bash

LLVM_PROFDATA=$(find ~/.rustup/toolchains -name "llvm-profdata" -type f 2>/dev/null | head -1)
LLVM_COV=$(find ~/.rustup/toolchains -name "llvm-cov" -type f 2>/dev/null | head -1)
echo "Using LLVM tools:"
echo "  profdata: $LLVM_PROFDATA"
echo "  cov: $LLVM_COV"

Step 4: Merge all profraw files

bash

cd /Users/michael/dev/pinhole
LLVM_PROFDATA=$(find ~/.rustup/toolchains -name "llvm-profdata" -type f 2>/dev/null | head -1)
$LLVM_PROFDATA merge -sparse $(find . -name "*.profraw" -type f) -o pinhole-combined.profdata
echo "Merged $(find . -name "*.profraw" -type f | wc -l) profraw files"

Step 5: Generate coverage report

bash

cd /Users/michael/dev/pinhole
LLVM_COV=$(find ~/.rustup/toolchains -name "llvm-cov" -type f 2>/dev/null | head -1)

$LLVM_COV report \
  --use-color \
  --instr-profile=pinhole-combined.profdata \
  --object target/debug/deps/pinhole-f2d40409e97edad8 \
  --object target/debug/deps/pinhole_client-8357b1173bc4a611 \
  --object target/debug/deps/pinhole_protocol-87558801f9169407 \
  --object target/debug/deps/action_dispatch_test-01015fd0d88dfe14 \
  --object target/debug/deps/client_server_test-3352a4d0dd8268bc \
  --object target/debug/deps/concurrent_connections_test-c695af612c5195eb \
  --object target/debug/deps/malformed_messages_test-7bcae52bc4bb5be1 \
  --object target/debug/deps/route_matching_test-04f8290cb25818d9 \
  --object target/debug/deps/storage_corruption_test-b8e06c1d4322ae4e \
  --object target/debug/deps/error_handling_test-32f92ec7df6e739a \
  --object target/debug/deps/message_serialization_test-6ab18a04f316113a \
  --object target/debug/deps/message_size_limit_test-23701d252bc9cf3e \
  --object target/debug/deps/tls_integration_test-a042db6c8858784d \
  --ignore-filename-regex='/.cargo/registry' \
  --ignore-filename-regex='rustc/' 2>&1

Note: If test binary hashes have changed (after code modifications), you'll see warnings about missing objects. The report will still work with the available binaries.

Step 6: Clean up coverage files

bash

cd /Users/michael/dev/pinhole
find . -name "*.profraw" -o -name "*.profdata" | xargs rm -f 2>/dev/null || true
echo "Cleaned up coverage files"

Expected Output

The final report shows a table with columns:

•Filename: Source file path
•Regions / Cover: Code regions and coverage percentage
•Functions / Executed: Functions and execution percentage
•Lines / Cover: Lines of code and coverage percentage
•Branches / Cover: Branch coverage (if available)
•TOTAL: Overall coverage across all files

Notes

•Target: 70%+ code coverage
•Last known: 87.73% overall coverage
•Test count: 113 tests across workspace
•Workspace crates: pinhole-framework, pinhole-client, pinhole-protocol, todomvc-example
•Binary hashes in step 5 may need updating after code changes