Stop lychee from causing so many PR failures

Author: trask

.github/scripts/link-check.sh

@@ -5,12 +5,42 @@ set -e
 export MSYS_NO_PATHCONV=1 # for Git Bash on Windows
 
 SCRIPT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")" && pwd)"
-LYCHEE_CONFIG="$SCRIPT_DIR/../../.lychee.toml"
+ROOT_DIR="$SCRIPT_DIR/../.."
 DEPENDENCIES_DOCKERFILE="$SCRIPT_DIR/dependencies.dockerfile"
 
+# Parse command line arguments
+RELATIVE_ONLY=false
+MODIFIED_FILES=""
+
+while [[ $# -gt 0 ]]; do
+    case $1 in
+        --relative-only)
+            RELATIVE_ONLY=true
+            shift
+            ;;
+        *)
+            # Treat any other arguments as file paths
+            MODIFIED_FILES="$MODIFIED_FILES $1"
+            shift
+            ;;
+    esac
+done
+
 # Extract lychee version from dependencies.dockerfile
 LYCHEE_VERSION=$(grep "FROM lycheeverse/lychee:" "$DEPENDENCIES_DOCKERFILE" | sed 's/.*FROM lycheeverse\/lychee:\([^ ]*\).*/\1/')
 
+# Determine target files/directories and config file
+TARGET="."
+LYCHEE_CONFIG="$SCRIPT_DIR/.lychee.toml"
+
+if [[ "$RELATIVE_ONLY" == "true" ]]; then
+    LYCHEE_CONFIG="$SCRIPT_DIR/.lychee-relative.toml"
+fi
+
+if [[ -n "$MODIFIED_FILES" ]]; then
+    TARGET="$MODIFIED_FILES"
+fi
+
 # Build the lychee command with optional GitHub token
 CMD="lycheeverse/lychee:$LYCHEE_VERSION --verbose --config $(basename "$LYCHEE_CONFIG")"
 
@@ -19,8 +49,7 @@ if [[ -n "$GITHUB_TOKEN" ]]; then
     CMD="$CMD --github-token $GITHUB_TOKEN"
 fi
 
-# Add the target directory
-CMD="$CMD ."
+CMD="$CMD $TARGET"
 
 # Determine if we should allocate a TTY
 DOCKER_FLAGS="--rm --init"
@@ -32,4 +61,4 @@ fi
 
 # Run lychee with proper signal handling
 # shellcheck disable=SC2086
-exec docker run $DOCKER_FLAGS -v "$(dirname "$LYCHEE_CONFIG")":/data -w /data $CMD
+exec docker run $DOCKER_FLAGS -v "$(dirname "$ROOT_DIR")":/data -w /data $CMD

.github/workflows/reusable-link-check.yml

@@ -11,8 +11,26 @@ jobs:
     runs-on: ubuntu-latest
     steps:
       - uses: actions/checkout@11bd71901bbe5b1630ceea73d27597364c9af683 # v4.2.2
+        with:
+          fetch-depth: 0 # needed for merge-base below
 
-      - name: Link check
+        # check relative links across all files since they could link to files that are modified in the PR
+      - name: Link check - relative links (all files)
         env:
           GITHUB_TOKEN: ${{ github.token }}
-        run: ./.github/scripts/link-check.sh
+        run: ./.github/scripts/link-check.sh --relative-only
+
+      - name: Get modified files
+        if: github.event_name == 'pull_request'
+        id: modified-files
+        run: |
+          merge_base=$(git merge-base ${{ github.base_ref }} ${{ github.event.pull_request.head.sha }})
+          modified_files=$(git diff --name-only $merge_base...${{ github.event.pull_request.head.sha }} | tr '\n' ' ')
+          echo "files=$modified_files" >> $GITHUB_OUTPUT
+          echo "Modified files: $modified_files"
+
+      - name: Link check - all links (modified files only)
+        if: github.event_name == 'pull_request' && steps.modified-files.outputs.files != ''
+        env:
+          GITHUB_TOKEN: ${{ github.token }}
+        run: ./.github/scripts/link-check.sh ${{ steps.modified-files.outputs.files }}