From 89a92971a3320c4ab1ce1c47feeb35eb3cd7e8c3 Mon Sep 17 00:00:00 2001
From: ICHINOSE Shogo <shogo82148@gmail.com>
Date: Mon, 2 Dec 2024 22:57:15 +0900
Subject: [PATCH] fix handling NaN

---
 encode.go      | 7 +++++--
 encode_test.go | 8 ++++++++
 2 files changed, 13 insertions(+), 2 deletions(-)

diff --git a/encode.go b/encode.go
index ae5cd91..0c93774 100644
--- a/encode.go
+++ b/encode.go
@@ -63,10 +63,13 @@ func (s *encodeState) encodeInteger(v int64) error {
 
 // encodeDecimal serializes an decimal according to RFC 8941 Section 4.1.5.
 func (s *encodeState) encodeDecimal(v float64) error {
-	i := int64(math.RoundToEven(v * 1000))
-	if i > MaxInteger || i < MinInteger {
+	if math.IsNaN(v) || math.IsInf(v, 0) {
+		return fmt.Errorf("sfv: decimal %f is not a finite number", v)
+	}
+	if v > MaxDecimal || v < MinDecimal {
 		return fmt.Errorf("sfv: decimal %f is out of range", v)
 	}
+	i := int64(math.RoundToEven(v * 1000))
 
 	// write the sign
 	if i < 0 {
diff --git a/encode_test.go b/encode_test.go
index 43beb5c..7fedba8 100644
--- a/encode_test.go
+++ b/encode_test.go
@@ -442,6 +442,14 @@ func TestEncode_invalidTypes(t *testing.T) {
 		t.Error("want error, not not")
 	}
 
+	// NaN
+	_, err = EncodeItem(Item{
+		Value: math.NaN(),
+	})
+	if err == nil {
+		t.Error("want error, not not")
+	}
+
 	// in Parameters
 	_, err = EncodeItem(Item{
 		Value: 1,