Refactor error handling and rename function for clarity

Improved error handling in several functions to make logic clearer and avoid potential issues. Renamed `expresion` to `expression` for correctness and updated related references. Consolidated redundant error paths and adjusted logic for better readability and maintainability.

Author: osmontero

correlation/cache/operators.go

@@ -12,16 +12,20 @@ import (
 
 func inCIDR(addr, network string) (bool, error) {
 	_, subnet, err := net.ParseCIDR(network)
-	if err == nil {
-		ip := net.ParseIP(addr)
-		if ip != nil {
-			if subnet.Contains(ip) {
-				return true, nil
-			}
-		}
+	if err != nil {
+		return false, fmt.Errorf("invalid CIDR")
+	}
+
+	ip := net.ParseIP(addr)
+	if ip == nil {
 		return false, fmt.Errorf("invalid IP address")
 	}
-	return false, err
+
+	if subnet.Contains(ip) {
+		return true, nil
+	}
+
+	return false, nil
 }
 
 func equal(val1, val2 string) bool {
@@ -54,25 +58,30 @@ func endWith(str, suff string) bool {
 	return strings.HasSuffix(str, suff)
 }
 
-func expresion(exp, str string) (bool, error) {
+func expression(exp, str string) (bool, error) {
 	re, err := regexp.Compile(exp)
-	if err == nil {
-		if re.MatchString(str) {
-			return true, nil
-		}
+	if err != nil {
+		return false, err
 	}
-	return false, err
+
+	if re.MatchString(str) {
+		return true, nil
+	}
+
+	return false, nil
 }
 
 func parseFloats(val1, val2 string) (float64, float64, error) {
-	f1, err1 := strconv.ParseFloat(val1, 64)
-	if err1 != nil {
-		return 0, 0, err1
+	f1, err := strconv.ParseFloat(val1, 64)
+	if err != nil {
+		return 0, 0, err
 	}
-	f2, err2 := strconv.ParseFloat(val2, 64)
-	if err2 != nil {
-		return 0, 0, err2
+
+	f2, err := strconv.ParseFloat(val2, 64)
+	if err != nil {
+		return 0, 0, err
 	}
+
 	return f1, f2, nil
 }
 
@@ -105,17 +114,17 @@ func compare(operator, val1, val2 string) bool {
 	case "not end with":
 		return !endWith(val1, val2)
 	case "regexp":
-		matched, err := expresion(val2, val1)
+		matched, err := expression(val2, val1)
 		if err != nil {
 			return false
 		}
 		return matched
 	case "not regexp":
-		matched, err := expresion(val2, val1)
+		matched, err := expression(val2, val1)
 		if err != nil {
 			return false
 		}
-		return matched
+		return !matched
 	case "<":
 		f1, f2, err := parseFloats(val1, val2)
 		if err != nil {
@@ -144,16 +153,16 @@ func compare(operator, val1, val2 string) bool {
 		return true
 	case "in cidr":
 		matched, err := inCIDR(val1, val2)
-		if err == nil {
-			return matched
+		if err != nil {
+			return false
 		}
-		return false
+		return matched
 	case "not in cidr":
 		matched, err := inCIDR(val1, val2)
-		if err == nil {
-			return !matched
+		if err != nil {
+			return false
 		}
-		return false
+		return !matched
 	default:
 		return false
 	}