tilaven/diff-coverage

⚡🧠️ diff-coverage

Diff-cover, supercharged in Rust 🦀. Get instant, actionable coverage insights at ⚡ blazing speed ⚡ with a 🧠️ tiny memory footprint 🧠️. Built for modern CI and massive repos, it turns slow coverage checks into fast, reliable feedback you can trust.

Usage

shell
diff-coverage coverage.xml --diff-file diff.diff

# Multiple coverage inputs (repeat or comma‑separated)
diff-coverage coverage1.xml coverage2.xml --diff-file diff.diff

# Multiple coverage inputs in a directory
diff-coverage ./coverage/ --diff-file diff.diff

# Fail the build if diff coverage drops below a threshold
diff-coverage ./coverage/ coverage.xml --diff-file diff.diff --fail-under 80

# Output to CI formats
diff-coverage coverage.xml --diff-file diff.diff --output gitlab=diff-cover.json
diff-coverage coverage.xml --diff-file diff.diff --output json=diff-cover.json --output summary

# Skip external packages from uncovered line calculations (regex supported)
diff-coverage coverage.xml --diff-file diff.diff --skip-coverage-path '^pkg/mongodb'

Options

• --diff-file : diff to analyze
• --fail-under : minimum acceptable diff coverage
• --missing-coverage : how to handle files missing from coverage (uncovered or ignore, default: ignore)
• --skip-coverage-path : regex of file paths to skip from uncovered line calculations (repeatable or comma-separated)
• --output <FORMAT=PATH>: output target(s), repeatable or comma‑separated Formats: cli, summary, gitlab, json (note: cli and summary don’t take a path)
• -h, --help: show help
• -V, --version: show version

Performance highlights

Benchmark 1

• Git diff file: 40MB size and 1,808,684 lines long
• Coverage file: 46MB size and 1,115,971 lines long

Benchmark 2

• Git diff file: 40MB size and 1,808,684 lines long
• 50 coverage files: each 620KB size and 24,116 lines long

Peak RSS shown in MB (kB ÷ 1024).
Full benchmark results

Installation

Prebuilt ***aries

Download the prebuilt archives from the https://github.com/tilaven/diff-coverage/releases.

Cargo install

bash
cargo install diff-coverage

Docker

bash
docker run --rm -v "$PWD":/work -w /work tilaven/diff-coverage:<version>-alpine \
  coverage.xml --diff-file diff.diff

Debian-based image (e.g. trixie) is available via versioned tags:

bash
docker run --rm -v "$PWD":/work -w /work tilaven/diff-coverage:<version>-debian-trixie \
  coverage.xml --diff-file diff.diff

Minimal scratch image is available via versioned tags:

bash
docker run --rm -v "$PWD":/work -w /work tilaven/diff-coverage:<version>-scratch \
  coverage.xml --diff-file diff.diff

Build

bash
cargo build

Run

bash
cargo run

Test

bash
cargo test

Release (GitHub Actions)

Push a version tag and GitHub Actions will run tests and attach executables to the GitHub Release:

bash
git tag v0.1.0
git push origin v0.1.0

Download the prebuilt archives from the GitHub Releases page.