A GitHub Action to add a coverage report, badge, and chart to your Go repo.

Apply it to your repo by adding this step to one of your workflows:

- name: Update coverage report
  uses: ncruces/go-coverage-report@v0

Your repo needs to have a Wiki for the action to work, and workflows need to have read and write permissions to the repo.

The action has 8 configuration knobs:

• coverage-file: optional coverage input file; default is to generate coverage for all packages in the current module.
• output-dir: optional output directory for the for the badge, report, chart; default is to generate files to the root of wiki.
• badge-style: optional coverage badge style, generated by shields.io; one of: flat (default), flat-square, plastic, for-the-badge, social.
• badge-title: optional coverage badge title; default is “coverage.”
• report: default true, generate an HTML coverage report.
• chart: default false, generate an SVG coverage chart.
• amend: default false, amend your Wiki, avoiding a series of “Update coverage” commits.

Also, consider:

• running this step after your tests run
  • coverage will fail if any test fails, so you may skip it if they fail
• running it only once per commit
  • use a condition to avoid repeated matrix runs
• skipping it for PRs
  • PRs lack permission to update the Wiki, nor would you want unsubmitted PRs to do so
• allowing it to fail without failing the entire job
  • if tests pass, the problem might be with the action itself, not your code

Complete example:

- name: Test
  run: go test -v ./...

- name: Update coverage report
  uses: ncruces/go-coverage-report@v0
  with:
    report: true
    chart: true
    amend: true
  if: |
    matrix.os == 'ubuntu-latest' &&
    github.event_name == 'push'  
  continue-on-error: true

The action generates an HTML report, SVG badge and chart, and saves them as “hidden” files in your Wiki.

To add a coverage badge to your README.md, use this Markdown snippet:

[![Go Coverage](https://github.com/USER/REPO/wiki/coverage.svg)](https://raw.githack.com/wiki/USER/REPO/coverage.html)

Clicking on the badge opens the coverage report. If you also want to show the coverage chart, create a Wiki page and link to it instead.

The action will also log to the Wiki the unix timestamp and coverage of every run, so it can generate the coverage chart.

• @vieux for gocover.io which I've used for years before creating this
• @Prounckk for the blog that prompted this solution
• raw.githack.com for proxying the HTML report
• shields.io for SVG badges
• quickchart.io for SVG charts