Covdir Report Action

A GitHub Action for generating simple code coverage reports from grcov-generated covdir files.

Usage

Structure your workflow to include the following steps:

1. Check out your code using the checkout action.
2. Install your nightly Rust toolchain. If you prefer to use stable, or anything other than nightly, then you must add RUSTC_BOOTSTRAP: '1' in the env section of the cargo steps below.
3. Build and test your code (in two separate steps) using the cargo action with some special compiler flags that are required for grcov to work:

env:
  CARGO_INCREMENTAL: '0'
  RUSTFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'
  RUSTDOCFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'

4. Install grcov using cargo; e.g.,

  - uses: actions-rs/cargo@v1
    with:
      command: install
      args: grcov

5. Run grcov in the root of your workspace, specifying covdir as the output format and the path to the output file (e.g., ./target/covdir.json). Add any other arguments required for your particular project; e.g.,

  - run: grcov . -s . --binary-path ./target/debug/ --excl-start '^mod\s+tests\s*\{$' -t covdir --branch --ignore-not-existing --keep-only 'src/**' -o ./target/covdir.json

6. Finally, run this action, passing the path to the previously generated covdir.json file as the minimum input:

  - uses: ecliptical/covdir-report-action@v1
    with:
      file: ./covdir.json

By default, the action only produces output variables with values from the root node of the covdir.json file:

• lines_covered
• lines_missed
• lines_total
• coverage_percent

Inputs

ID	Description	Required	Default
file	Path to covdir.json file	yes
summary	Write report to step summary if true	no	false
out	Write report to the given file	no
title	Report title	no	Line coverage

Outputs

ID	Description
lines_covered	Number of lines covered
lines_missed	Number of lines missed
lines_total	Total number of lines
coverage_percent	Percentage of lines covered

Example

An example workflow that builds and runs unit tests, collects test coverage, generates a simple markdown report, outputs it as the job sunmmary and posts it as a PR comment:

on:
  pull_request:
  push:
    branches:
      - main

name: Rust Coverage

jobs:
  coverage:
    runs-on: ubuntu-latest
    steps:
      - name: Check out the source code
        uses: actions/checkout@v3
      - name: Install Rust
        uses: actions-rs/toolchain@v1
        with:
          toolchain: 1.65.0
          override: true
      - name: Build the binary
        uses: actions-rs/cargo@v1
        with:
          command: build
        env:
          CARGO_INCREMENTAL: '0'
          RUSTC_BOOTSTRAP: '1'
          RUSTFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'
          RUSTDOCFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'
      - name: Run unit tests
        uses: actions-rs/cargo@v1
        with:
          command: test
        env:
          CARGO_INCREMENTAL: '0'
          RUSTC_BOOTSTRAP: '1'
          RUSTFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'
          RUSTDOCFLAGS: '-Zprofile -Ccodegen-units=1 -Cinline-threshold=0 -Clink-dead-code -Coverflow-checks=off -Cpanic=abort -Zpanic_abort_tests'
      - name: Install grcov
        uses: actions-rs/cargo@v1
        with:
          command: install
          args: grcov
      - name: Run grcov
        run: grcov . -s . --binary-path ./target/debug/ --excl-start '^mod\s+test(s)?\s*\{$' -t covdir --branch --ignore-not-existing --keep-only 'src/**' -o ./target/covdir.json
      - name: Generate coverage report
        uses: ecliptical/covdir-report-action@v0.1
        with:
          file: ./target/covdir.json
          summary: 'true'
          out: ./target/coverage.md
      - name: Add coverage comment to the pull request
        uses: marocchino/sticky-pull-request-comment@v2
        if: github.event_name == 'pull_request'
        with:
          hide_and_recreate: true
          hide_classify: "OUTDATED"
          path: ./target/coverage.md