From fcb472129bbf986f6100ca9662cff1706c93f977 Mon Sep 17 00:00:00 2001
From: Diego Henrique Oliveira <contato@diegoholiveira.com>
Date: Fri, 8 Dec 2023 10:06:48 -0300
Subject: [PATCH] Verify array before try to access any position

---
 jsonlogic_test.go | 10 ++++++++++
 vars.go           |  7 ++++++-
 2 files changed, 16 insertions(+), 1 deletion(-)

diff --git a/jsonlogic_test.go b/jsonlogic_test.go
index aa9e548..e7516fe 100644
--- a/jsonlogic_test.go
+++ b/jsonlogic_test.go
@@ -807,6 +807,16 @@ func TestIssue71_example_max(t *testing.T) {
 	assert.JSONEq(t, expected, result.String())
 }
 
+func TestIssue74(t *testing.T) {
+	logic := strings.NewReader(`{"if":[ false, {"var":"values.0.categories"}, "else" ]}`)
+	data := strings.NewReader(`{ "values": [] }`)
+
+	var result bytes.Buffer
+	_ = Apply(logic, data, &result)
+	expected := `"else"`
+	assert.JSONEq(t, expected, result.String())
+}
+
 func TestJsonLogicWithSolvedVars(t *testing.T) {
 	rule := json.RawMessage(`{
 		"or":[
diff --git a/vars.go b/vars.go
index d619e6e..3558899 100644
--- a/vars.go
+++ b/vars.go
@@ -91,7 +91,12 @@ func getVar(value, data interface{}) interface{} {
 		}
 
 		if isSlice(data) {
-			_value = data.([]interface{})[int(toNumber(part))]
+			pos := int(toNumber(part))
+			container := data.([]interface{})
+			if pos >= len(container) {
+				return _default
+			}
+			_value = container[pos]
 		}
 
 		if _value == nil {