add syntax check

.github/workflows/test-pr.yml

@@ -20,6 +20,29 @@ jobs:
           go-version-file: code/go.mod
           cache-dependency-path: code/go.sum
 
+      - name: Detect Changed Files
+        id: changes
+        run: |
+          cd code
+          CHANGES=$(git diff --name-only origin/${{ github.base_ref }} HEAD -- data/)
+
+          if [ -z "$CHANGES" ]; then
+            echo "No changes in data directory."
+            echo "has_changes=false" >> $GITHUB_OUTPUT
+          else
+            echo "Found changes in data directory."
+            echo "has_changes=true" >> $GITHUB_OUTPUT
+            FILES_CSV=$(echo "$CHANGES" | tr '\n' ',')
+            echo "files=$FILES_CSV" >> $GITHUB_ENV
+          fi
+
+      - name: Run Syntax Tests (Affected Files Only)
+        if: steps.changes.outputs.has_changes == 'true'
+        run: |
+          cd code || exit 1
+          export CHANGED_FILES="${{ env.files }}"
+          go test -v .
+
       - name: Set variables
         run: |
           echo "RELEASE_NAME=$(date +%Y%m%d%H%M%S)" >> $GITHUB_ENV

main_test.go

@@ -0,0 +1,118 @@
+package main
+
+import (
+	"os"
+	"path/filepath"
+	"regexp"
+	"strings"
+	"testing"
+)
+
+var validDomainRegexp = regexp.MustCompile(`^[a-z0-9_\-\.]+$`)
+
+func validateFile(t *testing.T, path string) {
+	list, err := Load(path)
+	if err != nil {
+		t.Errorf("❌ [Parse Error] File: %s | Error: %v", path, err)
+		return
+	}
+
+	for _, entry := range list.Entry {
+		switch entry.Type {
+		case "regexp":
+			if _, err := regexp.Compile(entry.Value); err != nil {
+				t.Errorf("❌ [Invalid Regex] File: %s | Rule: '%s' | Error: %v",
+					path, entry.Value, err)
+			}
+		case "domain", "full":
+			if strings.Contains(entry.Value, "http://") || strings.Contains(entry.Value, "https://") {
+				t.Errorf("❌ [Protocol Error] File: %s | Rule: '%s' | Remove http/s prefix",
+					path, entry.Value)
+			}
+			if strings.Contains(entry.Value, " ") {
+				t.Errorf("❌ [Spaces Error] File: %s | Rule: '%s' | Domain contains spaces",
+					path, entry.Value)
+			}
+			if !validDomainRegexp.MatchString(entry.Value) {
+				t.Errorf("❌ [Invalid Char] File: %s | Rule: '%s' | Contains illegal characters",
+					path, entry.Value)
+			}
+		case "include":
+			targetPath := filepath.Join("data", entry.Value)
+			if _, err := os.Stat(targetPath); os.IsNotExist(err) {
+				t.Errorf("❌ [Missing Include] File: %s | Target: '%s' does not exist",
+					path, entry.Value)
+			}
+		}
+	}
+}
+
+func TestDataSyntax(t *testing.T) {
+	changedFilesEnv := os.Getenv("CHANGED_FILES")
+
+	if changedFilesEnv != "" {
+		rawFiles := strings.Split(changedFilesEnv, ",")
+		var targetFiles []string
+
+		for _, f := range rawFiles {
+			f = strings.TrimSpace(f)
+			if f == "" {
+				continue
+			}
+			if strings.HasPrefix(f, "data/") || strings.HasPrefix(f, "data\\") {
+				if _, err := os.Stat(f); err == nil {
+					targetFiles = append(targetFiles, f)
+				}
+			}
+		}
+
+		total := len(targetFiles)
+		if total == 0 {
+			t.Log("ℹ️ CHANGED_FILES was set, but no valid 'data/' files were found to test.")
+			return
+		}
+
+		t.Logf("📝 Validating %d specific file(s):", total)
+		displayLimit := 5
+		for i, f := range targetFiles {
+			if i >= displayLimit {
+				t.Logf("   ... and %d more files.", total-i)
+				break
+			}
+			t.Logf("   - %s", f)
+		}
+		t.Log("---------------------------------------------------")
+
+		for _, f := range targetFiles {
+			validateFile(t, f)
+		}
+
+	} else {
+		dataDir := "data"
+		if _, err := os.Stat(dataDir); os.IsNotExist(err) {
+			t.Fatalf("Data directory '%s' not found.", dataDir)
+		}
+
+		t.Log("---------------------------------------------------")
+		t.Log("🌍 CHANGED_FILES not set. Running FULL syntax check on 'data/'...")
+		t.Log("---------------------------------------------------")
+
+		count := 0
+		err := filepath.Walk(dataDir, func(path string, info os.FileInfo, err error) error {
+			if err != nil {
+				return err
+			}
+			if info.IsDir() {
+				return nil
+			}
+			count++
+			validateFile(t, path)
+			return nil
+		})
+
+		if err != nil {
+			t.Fatalf("Failed to walk data directory: %v", err)
+		}
+		t.Logf("✅ Checked %d files in total.", count)
+	}
+}