Add schema validation workflow and update detect-file-changes github action to output the detected files

Author: jormundur00

.github/actions/detect-file-changes/action.yml

@@ -15,3 +15,5 @@ runs:
 outputs:
   changed:
     description: "Returns `true` if any changed file matches the specified patterns, `false` otherwise."
+  changed_files:
+    description: "Returns a space-separated list of all changed files that match the specified patterns, or an empty list if none match."

.github/actions/detect-file-changes/detect-file-changes.js

@@ -232,15 +232,23 @@ function fileMatches(file, compiled) {
     changedFiles.forEach(f => console.log(`- ${f}`));
 
     // Check if any file matches
-    const matched = changedFiles.some(f => fileMatches(f, compiled));
+    const matchedFiles = changedFiles.filter(f => fileMatches(f, compiled));
+    const matched = matchedFiles.length > 0;
 
-    // Write GitHub Action output
+    // Write GitHub Action outputs
     fs.appendFileSync(
       process.env.GITHUB_OUTPUT,
       `changed=${matched ? 'true' : 'false'}\n`
     );
 
-    console.log(`Files match filter → ${matched}`);
+    // Write the list of matched files as a multiline output
+    fs.appendFileSync(
+      process.env.GITHUB_OUTPUT,
+      `changed_files=${matchedFiles.join(' ')}\n`
+    );
+
+    console.log(`Files matching filter (${matchedFiles.length}):`);
+    matchedFiles.forEach(f => console.log(`- ${f}`));
   } catch (err) {
     console.log(`file-filter encountered an error: ${err?.message || err}`);
     process.exit(0); // Non-fatal for CI

.github/workflows/index-file-validation.yml

@@ -0,0 +1,90 @@
+name: "Validate index.json files"
+
+on:
+  pull_request:
+
+jobs:
+  validate-json:
+    name: "📋 Validate changed JSON files"
+    runs-on: ubuntu-22.04
+    timeout-minutes: 10
+
+    steps:
+      - name: "☁️ Checkout repository"
+        uses: actions/checkout@v4
+
+      - name: "🔎 Detect relevant file changes"
+        id: filter
+        uses: ./.github/actions/detect-file-changes
+        with:
+          file-patterns: |
+            - 'metadata/index.json'
+            - 'metadata/*/*/index.json'
+            - 'tests/src/index.json'
+            - 'tests/src/*/*/*/index.json'
+          github_token: ${{ secrets.GITHUB_TOKEN }}
+
+      - name: "Setup Python"
+        if: steps.filter.outputs.changed == 'true'
+        uses: actions/setup-python@v4
+        with:
+          python-version: '3.10'
+
+      - name: "Install validation tools"
+        if: steps.filter.outputs.changed == 'true'
+        run: |
+          pip install jq check-jsonschema
+
+      - name: "Check that the changed index.json files conform to their schemas"
+        if: steps.filter.outputs.changed == 'true'
+        run: |
+          set -e
+          
+          # Treat changed_files as a proper array
+          FILES=(${{ steps.filter.outputs.changed_files }})
+          
+          # Track failures
+          FAILURES=()
+          
+          for FILE in "${FILES[@]}"; do
+        
+            # Determine schema for each file
+            if [[ "$FILE" == "metadata/index.json" ]]; then
+              SCHEMA="schemas/metadata-root-index-schema-v1.0.0.json"
+            elif [[ "$FILE" == metadata/*/*/index.json ]]; then
+              SCHEMA="schemas/metadata-library-index-schema-v1.0.0.json"
+            elif [[ "$FILE" == "tests/src/index.json" ]]; then
+              SCHEMA="schemas/tests-root-index-schema-v1.0.0.json"
+            elif [[ "$FILE" == tests/src/*/*/*/index.json ]]; then
+              SCHEMA="schemas/tests-project-index-schema-v1.0.0.json"
+            else
+              echo "ℹ️ Skipping: $FILE (no schema mapping)"
+              continue
+            fi
+          
+            echo "🔍 Validating $FILE using $SCHEMA"
+          
+            # Step 1: Check JSON well-formedness
+            if ! jq -e . "$FILE" >/dev/null; then
+              echo "❌ $FILE is not valid JSON"
+              FAILURES+=("$FILE (invalid JSON)")
+              continue
+            fi
+          
+            # Step 2: Validate against schema
+            if ! check-jsonschema --schemafile "$SCHEMA" "$FILE"; then
+              FAILURES+=("$FILE (schema validation failed)")
+              continue
+            fi
+          
+            echo "✅ $FILE validated successfully"
+          done
+          
+          # Fail at the end if any errors occurred
+          if [ ${#FAILURES[@]} -ne 0 ]; then
+            echo "::error ::Some files failed validation:"
+          for f in "${FAILURES[@]}"; do
+            echo "::error ::  $f"
+          done
+            exit 1
+          fi