From ba161f5eb3c0c96f4ef486a6c15f6721895172fe Mon Sep 17 00:00:00 2001
From: rabbitstack <rabbitstack7@gmail.com>
Date: Sat, 28 Mar 2026 22:41:50 +0100
Subject: [PATCH] fix(filter): Include field argument in valuer

If the field supports arguments, the
name of the field passed to the valuer must include the argument as well.
---
 pkg/filter/filter.go     | 21 +++++++++++++++++----
 pkg/filter/ql/ast.go     |  9 +++++----
 pkg/filter/ql/literal.go | 11 ++++++++++-
 3 files changed, 32 insertions(+), 9 deletions(-)

diff --git a/pkg/filter/filter.go b/pkg/filter/filter.go
index 9c662361e..eb6eb2e5e 100644
--- a/pkg/filter/filter.go
+++ b/pkg/filter/filter.go
@@ -71,6 +71,19 @@ type Field struct {
 	Arg   string
 }
 
+func (f *Field) String() string {
+	if f.Arg != "" {
+		var b strings.Builder
+		b.Grow(len(f.Value) + len(f.Arg) + 2)
+		b.WriteString(f.Value)
+		b.WriteByte('[')
+		b.WriteString(f.Arg)
+		b.WriteByte(']')
+		return b.String()
+	}
+	return f.Value
+}
+
 // BoundField contains the field meta attributes in addition to bound field specific fields.
 type BoundField struct {
 	Field    Field
@@ -489,15 +502,15 @@ func (f *filter) mapValuer(evt *event.Event) map[string]any {
 			v, err := accessor.Get(field, evt)
 			if v == nil || err != nil {
 				if v == nil {
-					valuer[field.Value] = defaultAccessorValue(field)
+					valuer[field.String()] = defaultAccessorValue(field)
 				}
 				if err != nil && !errs.IsParamNotFound(err) {
-					valuer[field.Value] = defaultAccessorValue(field)
+					valuer[field.String()] = defaultAccessorValue(field)
 					accessorErrors.Add(err.Error(), 1)
 				}
 				continue
 			}
-			valuer[field.Value] = v
+			valuer[field.String()] = v
 			break
 		}
 	}
@@ -507,7 +520,7 @@ func (f *filter) mapValuer(evt *event.Event) map[string]any {
 // addField appends a new field to the filter fields list.
 func (f *filter) addField(field *ql.FieldLiteral) {
 	for _, f := range f.fields {
-		if f.Value == field.Value {
+		if f.String() == field.String() {
 			return
 		}
 	}
diff --git a/pkg/filter/ql/ast.go b/pkg/filter/ql/ast.go
index ba8147122..a47df43ed 100644
--- a/pkg/filter/ql/ast.go
+++ b/pkg/filter/ql/ast.go
@@ -21,12 +21,13 @@
 package ql
 
 import (
-	fuzzysearch "github.com/lithammer/fuzzysearch/fuzzy"
-	"github.com/rabbitstack/fibratus/pkg/util/sets"
-	"github.com/rabbitstack/fibratus/pkg/util/wildcard"
 	"net"
 	"strconv"
 	"strings"
+
+	fuzzysearch "github.com/lithammer/fuzzysearch/fuzzy"
+	"github.com/rabbitstack/fibratus/pkg/util/sets"
+	"github.com/rabbitstack/fibratus/pkg/util/wildcard"
 )
 
 // Eval evaluates expr against a map that contains the field values.
@@ -198,7 +199,7 @@ func (v *ValuerEval) Eval(expr Expr) interface{} {
 	case *BoolLiteral:
 		return expr.Value
 	case *FieldLiteral:
-		val, ok := v.Valuer.Value(expr.Value)
+		val, ok := v.Valuer.Value(expr.String())
 		if !ok {
 			return nil
 		}
diff --git a/pkg/filter/ql/literal.go b/pkg/filter/ql/literal.go
index 99aac363a..65140dea1 100644
--- a/pkg/filter/ql/literal.go
+++ b/pkg/filter/ql/literal.go
@@ -98,7 +98,16 @@ func (s StringLiteral) String() string {
 	return s.Value
 }
 
-func (f FieldLiteral) String() string {
+func (f *FieldLiteral) String() string {
+	if f.Arg != "" {
+		var b strings.Builder
+		b.Grow(len(f.Value) + len(f.Arg) + 2)
+		b.WriteString(f.Value)
+		b.WriteByte('[')
+		b.WriteString(f.Arg)
+		b.WriteByte(']')
+		return b.String()
+	}
 	return f.Value
 }