chore: do a nil check for all but == and != ops

pkg/query-service/queryBuilderToExpr/queryBuilderToExpr.go

@@ -8,7 +8,6 @@ import (
 	expr "github.com/antonmedv/expr"
 	v3 "go.signoz.io/signoz/pkg/query-service/model/v3"
 	"go.uber.org/zap"
-	"golang.org/x/exp/slices"
 )
 
 var logOperatorsToExpr = map[v3.FilterOperator]string{
@@ -65,18 +64,11 @@ func Parse(filters *v3.FilterSet) (string, error) {
 			filter = fmt.Sprintf("%s %s %s", exprFormattedValue(v.Key.Key), logOperatorsToExpr[v.Operator], getTypeName(v.Key.Type))
 		default:
 			filter = fmt.Sprintf("%s %s %s", name, logOperatorsToExpr[v.Operator], exprFormattedValue(v.Value))
-		}
 
-		if slices.Contains(
-			[]v3.FilterOperator{
-				v3.FilterOperatorContains,
-				v3.FilterOperatorNotContains,
-				v3.FilterOperatorRegex,
-				v3.FilterOperatorNotRegex,
-			},
-			v.Operator,
-		) {
-			filter = fmt.Sprintf("%s != nil && %s", name, filter)
+			// Avoid running operators on nil values
+			if v.Operator != v3.FilterOperatorEqual && v.Operator != v3.FilterOperatorNotEqual {
+				filter = fmt.Sprintf("%s != nil && %s", name, filter)
+			}
 		}
 
 		// check if the filter is a correct expression language