Check JSON syntax for pull requests (AliceO2Group#1454)

Author: TimoWilken

.github/workflows/check-json-syntax.yml

@@ -0,0 +1,37 @@
+---
+name: Validate JSON syntax
+
+# Run on any commit or PR that changes any JSON file.
+'on':
+  push:
+    paths:
+      - '**.json'
+  pull_request:
+    paths:
+      - '**.json'
+
+permissions: {}
+
+jobs:
+  json-syntax:
+    name: validate syntax
+    runs-on: ubuntu-latest
+
+    steps:
+      - name: Checkout code
+        uses: actions/checkout@v4
+
+      - name: Validate syntax for JSON files
+        run: |
+          error=0
+          readarray -d '' json_files < \
+            <(find . \( -path ./.git -or -path ./DATA/testing/private \) -prune -false -or -type f -name '*.json' -print0)
+          for jsonf in "${json_files[@]}"; do
+            echo "::debug::Checking $jsonf..."
+            if ! errmsg=$(jq . "$jsonf" 2>&1 >/dev/null); then
+              error=1
+              echo "Invalid JSON syntax found in $jsonf:" >&2
+              printf '::error file=%s,title=%s::%s\n' "$jsonf" 'Invalid JSON syntax' "$errmsg"
+            fi
+          done
+          exit "$error"