add code coverage

.github/workflows/R-CMD-check.yaml

@@ -33,6 +33,7 @@ jobs:
 
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+      CODECOV_TOKEN: ${{ secrets.CODECOV_TOKEN }}
       R_KEEP_PKG_SOURCE: yes
       _R_CHECK_FORCE_SUGGESTS_: false
       _R_CHECK_RD_XREFS_: false
@@ -72,6 +73,13 @@ jobs:
           R CMD build litedown
           R CMD check --as-cran --no-manual litedown_*.tar.gz
 
+      - name: Test coverage
+        if: success() && runner.os == 'Linux' && matrix.config.r == 'release'
+        run: |
+          pak::pkg_install('covr')
+          covr::codecov()
+        shell: Rscript {0}
+
       - uses: actions/checkout@HEAD
         if: runner.os == 'macOS'
         with:

README.md

@@ -15,6 +15,8 @@
 release](https://www.r-pkg.org/badges/version/litedown)](https://cran.r-project.org/package=litedown)
 [![litedown on
 r-universe](https://yihui.r-universe.dev/badges/litedown)](https://yihui.r-universe.dev/litedown)
+[![Codecov test
+coverage](https://codecov.io/gh/yihui/litedown/branch/main/graph/badge.svg)](https://app.codecov.io/gh/yihui/litedown?branch=main)
 
 <!-- badges: end -->