Automatically skip when pandoc not installed (#1942)

.github/workflows/no-pandoc.yaml

@@ -0,0 +1,36 @@
+# Workflow derived from https://github.com/r-lib/actions/tree/master/examples
+# Need help debugging build failures? Start at https://github.com/r-lib/actions#where-to-find-help
+on:
+  push:
+    branches: [main, master]
+  pull_request:
+    branches: [main, master]
+
+name: no-pandoc
+
+jobs:
+  R-CMD-check:
+    runs-on: ubuntu-latest
+    env:
+      GITHUB_PAT: ${{ secrets.GITHUB_TOKEN }}
+      R_KEEP_PKG_SOURCE: yes
+    steps:
+      - uses: actions/checkout@v2
+
+      - uses: r-lib/actions/setup-r@v1
+        with:
+          use-public-rspm: true
+
+      - uses: r-lib/actions/setup-r-dependencies@v1
+        with:
+          extra-packages: rcmdcheck
+
+      - uses: r-lib/actions/check-r-package@v1
+        with:
+          build_args: "'--no-manual'"
+
+      - name: Show testthat output
+        if: always()
+        run: find check -name 'testthat.Rout*' -exec cat '{}' \; || true
+        shell: bash
+

R/markdown.R

@@ -98,7 +98,11 @@ convert_markdown_to_html <- function(in_path, out_path, ...) {
   } else if (rmarkdown::pandoc_available("1.12.3")) {
     from <- "markdown_github-hard_line_breaks+tex_math_dollars+tex_math_single_backslash+header_attributes"
   } else {
-    stop("Pandoc not available", call. = FALSE)
+    if (is_testing()) {
+      testthat::skip("Pandoc not available")
+    } else {
+      abort("Pandoc not available")
+    }
   }
 
   rmarkdown::pandoc_convert(