cargo-llvm-cov vs ReportGenerator

cargo-llvm-cov is a Cargo subcommand that uses rustc’s LLVM source-based instrumentation to generate code coverage reports. It works with cargo test, cargo run, and cargo nextest through a Cargo-compatible command-line interface, and supports proc-macro UI tests. Line and region coverage are available; branch coverage is optional and requires nightly Rust. Doc-test coverage is also optional and requires nightly features. Reports can be generated as text, HTML, JSON, LCOV, Cobertura XML, or Codecov Custom Coverage format. The project provides GitHub Actions examples for uploading reports to Codecov and a GitLab CI example using Cobertura output. LCOV results can be viewed in VS Code with the Coverage Gutters extension. With compatible Clang and LLVM tools configured, the tool can include C and C++ code linked to a Rust library or binary. It supports Linux, macOS, and Windows, and is licensed under either Apache-2.0 or MIT at the user's choice. Installation requires rustc 1.87 or newer, while running it requires Cargo 1.60 or newer. Branch and doc-test coverage are unstable and have known issues, respectively.

ReportGenerator is a command-line tool that turns code coverage reports into readable reports and visualizes covered source lines. It runs on Windows, Linux, and macOS, and accepts input from tools and formats including coverlet, OpenCover, dotCover, Visual Studio, NCover, Cobertura, JaCoCo, Clover, gcov, and lcov. Reports visualize line and branch coverage; method coverage is a PRO feature. A history chart tracks coverage over time, and the summary table can be filtered and sorted. Risk hotspot analysis can use cyclomatic complexity, NPath complexity, and CRAP score when those values are available, with configurable warning thresholds. Output choices include HTML, Clover, Cobertura, OpenCover, SonarQube, lcov, TeamCity summary, XML, Markdown, JSON, CSV, and text. The maker says GitHub Actions and Azure DevOps are supported. The project is open source under the Apache License, with basic features free and additional features requiring PRO. Lifetime licenses cost $79 as a one-time purchase for an individual, $249, paid once for up to 10 developers, or $599, paid once for unlimited developers.