From 33a97bfcd323e22dc60ff4402adcfe9047b3bd7b Mon Sep 17 00:00:00 2001
From: Shaurya Kesarwani <kesar.shaurya@gmail.com>
Date: Mon, 26 Oct 2026 12:14:41 +0530
Subject: [PATCH] Return an error instead of panicking on integer division by
 zero

Value.Divide and Value.Modulo used Go's integer / and % directly when both
operands were ints, so a selector such as `1 / 0` or `5 % 0` crashed the
process with "panic: runtime error: integer divide by zero". Check the
divisor first and return ErrDivisionByZero instead.
---
 model/error.go           |  8 +++++++-
 model/value_math.go      |  6 ++++++
 model/value_math_test.go | 16 ++++++++++++++++
 3 files changed, 29 insertions(+), 1 deletion(-)

diff --git a/model/error.go b/model/error.go
index 8cadf36a..f7b75b92 100644
--- a/model/error.go
+++ b/model/error.go
@@ -1,6 +1,12 @@
 package model
 
-import "fmt"
+import (
+	"errors"
+	"fmt"
+)
+
+// ErrDivisionByZero is returned when an integer is divided by zero.
+var ErrDivisionByZero = errors.New("integer division by zero")
 
 // MapKeyNotFound is returned when a key is not found in a map.
 type MapKeyNotFound struct {
diff --git a/model/value_math.go b/model/value_math.go
index e7b7a6cf..24e9a225 100644
--- a/model/value_math.go
+++ b/model/value_math.go
@@ -174,6 +174,9 @@ func (v *Value) Divide(other *Value) (*Value, error) {
 		if err != nil {
 			return nil, err
 		}
+		if b == 0 {
+			return nil, ErrDivisionByZero
+		}
 		return NewValue(a / b), nil
 	}
 	if v.IsFloat() && other.IsFloat() {
@@ -223,6 +226,9 @@ func (v *Value) Modulo(other *Value) (*Value, error) {
 		if err != nil {
 			return nil, err
 		}
+		if b == 0 {
+			return nil, ErrDivisionByZero
+		}
 		return NewValue(a % b), nil
 	}
 	if v.IsFloat() && other.IsFloat() {
diff --git a/model/value_math_test.go b/model/value_math_test.go
index f6b80e54..a10fa115 100644
--- a/model/value_math_test.go
+++ b/model/value_math_test.go
@@ -1,6 +1,7 @@
 package model_test
 
 import (
+	"errors"
 	"testing"
 
 	"github.com/tomwright/dasel/v3/model"
@@ -148,3 +149,18 @@ func TestValue_Modulo(t *testing.T) {
 		t.Run("float", run(model.NewFloatValue(10), model.NewFloatValue(3), model.NewFloatValue(1)))
 	})
 }
+
+func TestValue_IntegerDivisionByZero(t *testing.T) {
+	t.Run("divide", func(t *testing.T) {
+		_, err := model.NewIntValue(1).Divide(model.NewIntValue(0))
+		if !errors.Is(err, model.ErrDivisionByZero) {
+			t.Errorf("expected %v, got %v", model.ErrDivisionByZero, err)
+		}
+	})
+	t.Run("modulo", func(t *testing.T) {
+		_, err := model.NewIntValue(1).Modulo(model.NewIntValue(0))
+		if !errors.Is(err, model.ErrDivisionByZero) {
+			t.Errorf("expected %v, got %v", model.ErrDivisionByZero, err)
+		}
+	})
+}