[ci][docs][R-package] catch builds that have not updated docs (#3205)

* [ci] [R-package] catch builds that have not updated docs

* drop reliance on .Renviron

* remove docs changes

* Update .ci/test_r_package.sh
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

* make all R tasks start with r-package
Co-authored-by: Nikita Titov <nekit94-08@mail.ru>

.ci/test.sh

@@ -69,7 +69,7 @@ if [[ $TASK == "if-else" ]]; then
     exit 0
 fi
 
-if [[ $TASK == "r-package" ]]; then
+if [[ "${TASK:0:9}" == "r-package" ]]; then
     bash ${BUILD_DIRECTORY}/.ci/test_r_package.sh || exit -1
     exit 0
 fi

.ci/test_r_package.sh

@@ -4,7 +4,7 @@
 CRAN_MIRROR="https://cloud.r-project.org/"
 R_LIB_PATH=~/Rlib
 mkdir -p $R_LIB_PATH
-echo "R_LIBS=$R_LIB_PATH" > ${HOME}/.Renviron
+export R_LIBS=$R_LIB_PATH
 export PATH="$R_LIB_PATH/R/bin:$PATH"
 
 # Get details needed for installing R components
@@ -90,6 +90,24 @@ if [[ $OS_NAME == "macos" ]]; then
 fi
 Rscript --vanilla -e "install.packages(${packages}, repos = '${CRAN_MIRROR}', lib = '${R_LIB_PATH}', dependencies = c('Depends', 'Imports', 'LinkingTo'))" || exit -1
 
+if [[ $TASK == "r-package-check-docs" ]]; then
+    Rscript build_r.R || exit -1
+    Rscript --vanilla -e "install.packages('roxygen2', repos = '${CRAN_MIRROR}', lib = '${R_LIB_PATH}', dependencies = c('Depends', 'Imports', 'LinkingTo'))" || exit -1
+    Rscript --vanilla -e "roxygen2::roxygenize('R-package/', load = 'installed')" || exit -1
+    num_doc_files_changed=$(
+        git diff --name-only | grep -E "\.Rd|NAMESPACE" | wc -l
+    )
+    if [[ ${num_doc_files_changed} -gt 0 ]]; then
+        echo "Some R documentation files have changed. Please re-generate them and commit those changes."
+        echo ""
+        echo "    Rscript build_r.R"
+        echo "    Rscript -e \"roxygen2::roxygenize('R-package/', load = 'installed')\""
+        echo ""
+        exit -1
+    fi
+    exit 0
+fi
+
 cd ${BUILD_DIRECTORY}
 Rscript build_r.R --skip-install || exit -1
 

.github/workflows/main.yml

@@ -32,6 +32,10 @@ jobs:
             task: r-package
             compiler: clang
             r_version: 4.0
+          - os: ubuntu-latest
+            task: r-package-check-docs
+            compiler: gcc
+            r_version: 4.0
           - os: macOS-latest
             task: r-package
             compiler: gcc