Add sanity check for absolute paths

.github/workflows/CI.yml

@@ -86,3 +86,18 @@ jobs:
             Name ends with space or period: period.
             Name ends with space or period: space 
           EOF
+
+      - name: "Test check_absolute_paths.sh"
+        shell: bash
+        run: |
+          mkdir -p paths-dir/doc
+          cd paths-dir
+          ../check_absolute_paths.sh > $RUNNER_TEMP/absolute_paths_run.txt # empty folder, so should not give error
+          echo "<a href=\"/home/runner/gap/pkg/awesomepackage/doc/chap66_mj.html#ABC123\">Link</a>" > doc/chap1_mj.html
+          echo "<a href=\"file:///home/runner/gap/pkg/awesomepackage/doc/chap66_mj.html#ABC123\">Link</a>" > doc/chap2_mj.html
+          echo "<a href=\"../../../pkg/awesomepackage/doc/chap66_mj.html#ABC123\">Link</a>" > doc/chap3_mj.html
+          ../check_absolute_paths.sh > $RUNNER_TEMP/absolute_paths_run.txt || true # suppress expected error here
+          diff <(sort $RUNNER_TEMP/absolute_paths_run.txt) - <<EOF
+          ./doc/chap1_mj.html
+          ./doc/chap2_mj.html
+          EOF

action.yml

@@ -23,6 +23,14 @@ runs:
       shell: bash
       run: |
         gap -A -q -c 'QuitGap(ValidatePackageInfo("PackageInfo.g"));'
+
+    - name: "Check documentation for absolute paths"
+      shell: bash
+      run: |
+        $GITHUB_ACTION_PATH/check_absolute_paths.sh || {
+          echo "::error::Found absolute paths in HTML file(s)"
+          exit 1
+        }
 
     - name: "Create assets folder"
       shell: bash

check_absolute_paths.sh

@@ -0,0 +1,7 @@
+#!/usr/bin/env bash
+set -e
+set -o pipefail
+
+if grep -rlE '<a href="(file:/)?/' . --include='*.htm*' ; then
+  exit 1
+fi