BIG CHECK!

Author: mhpob

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

@@ -10,15 +10,33 @@ name: R-CMD-check
 
 jobs:
   R-CMD-check:
-    runs-on: ubuntu-latest
+    runs-on: ${{ matrix.config.os }}
+
+    name: ${{ matrix.config.os }} (${{ matrix.config.r }})
+
+    strategy:
+      fail-fast: false
+      matrix:
+        config:
+          - {os: macos-latest,   r: 'release'}
+          - {os: windows-latest, r: 'release'}
+          - {os: ubuntu-latest,   r: 'devel', http-user-agent: 'release'}
+          - {os: ubuntu-latest,   r: 'release'}
+          - {os: ubuntu-latest,   r: 'oldrel-1'}
+
     env:
       GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
       R_KEEP_PKG_SOURCE: yes
+
     steps:
       - uses: actions/checkout@v3
 
+      - uses: r-lib/actions/setup-pandoc@v2
+
       - uses: r-lib/actions/setup-r@v2
         with:
+          r-version: ${{ matrix.config.r }}
+          http-user-agent: ${{ matrix.config.http-user-agent }}
           use-public-rspm: true
 
       - uses: r-lib/actions/setup-r-dependencies@v2
@@ -27,3 +45,5 @@ jobs:
           needs: check
 
       - uses: r-lib/actions/check-r-package@v2
+        with:
+          upload-snapshots: true