From 986a8442c966d3c90ccccc74c01a508d06a3fa47 Mon Sep 17 00:00:00 2001
From: mido <mido@numinix.com>
Date: Thu, 24 Mar 2022 07:22:25 -0700
Subject: [PATCH] Fix panic if the condition is empty

---
 parser/parser.go      | 4 ++++
 parser/parser_test.go | 8 ++++++++
 2 files changed, 12 insertions(+)

diff --git a/parser/parser.go b/parser/parser.go
index 370a83d..d3563b0 100644
--- a/parser/parser.go
+++ b/parser/parser.go
@@ -814,6 +814,10 @@ func (p *parser) registerInfix(tokenType token.Type, fn infixParseFn) {
 }
 
 func (p *parser) confrimIfCondition(v ast.Expression) (returnData bool) {
+	if v == nil {
+		p.invalidIfCondition("missing condition in if statement")
+		return
+	}
 	_, ok := v.(ast.Comparable)
 	if !ok {
 		p.invalidIfCondition(v.String())
diff --git a/parser/parser_test.go b/parser/parser_test.go
index ec57e55..7fe220e 100644
--- a/parser/parser_test.go
+++ b/parser/parser_test.go
@@ -1114,6 +1114,14 @@ func Test_Break_IfCondtion(t *testing.T) {
 	r.Error(err)
 }
 
+func Test_Empty_IfCondtion(t *testing.T) {
+	r := require.New(t)
+	input := `<% if() { v } %>`
+
+	_, err := Parse(input)
+	r.Error(err)
+}
+
 func Test_Continue_Function(t *testing.T) {
 	r := require.New(t)
 	input := `<% fn(x, y) { continue } %>`