From 26f8e1321cf66395a76e4671e6e67f4cc37f84cf Mon Sep 17 00:00:00 2001
From: Greg <greg@toki.waseda.jp>
Date: Fri, 15 Dec 2017 00:31:55 +0900
Subject: [PATCH] float: return error when marshaling NaN or Inf

---
 float.go           |  7 +++++++
 float_test.go      | 15 +++++++++++++++
 zero/float.go      |  7 +++++++
 zero/float_test.go | 15 +++++++++++++++
 4 files changed, 44 insertions(+)

diff --git a/float.go b/float.go
index 5d55229..8c39e3b 100644
--- a/float.go
+++ b/float.go
@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
+	"math"
 	"reflect"
 	"strconv"
 )
@@ -91,6 +92,12 @@ func (f Float) MarshalJSON() ([]byte, error) {
 	if !f.Valid {
 		return []byte("null"), nil
 	}
+	if math.IsInf(f.Float64, 0) || math.IsNaN(f.Float64) {
+		return nil, &json.UnsupportedValueError{
+			Value: reflect.ValueOf(f.Float64),
+			Str:   strconv.FormatFloat(f.Float64, 'g', -1, 64),
+		}
+	}
 	return []byte(strconv.FormatFloat(f.Float64, 'f', -1, 64)), nil
 }
 
diff --git a/float_test.go b/float_test.go
index 6be025a..bf9c833 100644
--- a/float_test.go
+++ b/float_test.go
@@ -2,6 +2,7 @@ package null
 
 import (
 	"encoding/json"
+	"math"
 	"testing"
 )
 
@@ -170,6 +171,20 @@ func TestFloatScan(t *testing.T) {
 	assertNullFloat(t, null, "scanned null")
 }
 
+func TestFloatInfNaN(t *testing.T) {
+	nan := NewFloat(math.NaN(), true)
+	_, err := nan.MarshalJSON()
+	if err == nil {
+		t.Error("expected error for NaN, got nil")
+	}
+
+	inf := NewFloat(math.Inf(1), true)
+	_, err = inf.MarshalJSON()
+	if err == nil {
+		t.Error("expected error for Inf, got nil")
+	}
+}
+
 func assertFloat(t *testing.T, f Float, from string) {
 	if f.Float64 != 1.2345 {
 		t.Errorf("bad %s float: %f ≠ %f\n", from, f.Float64, 1.2345)
diff --git a/zero/float.go b/zero/float.go
index ccf6ef6..e998543 100644
--- a/zero/float.go
+++ b/zero/float.go
@@ -4,6 +4,7 @@ import (
 	"database/sql"
 	"encoding/json"
 	"fmt"
+	"math"
 	"reflect"
 	"strconv"
 )
@@ -92,6 +93,12 @@ func (f Float) MarshalJSON() ([]byte, error) {
 	if !f.Valid {
 		n = 0
 	}
+	if math.IsInf(f.Float64, 0) || math.IsNaN(f.Float64) {
+		return nil, &json.UnsupportedValueError{
+			Value: reflect.ValueOf(f.Float64),
+			Str:   strconv.FormatFloat(f.Float64, 'g', -1, 64),
+		}
+	}
 	return []byte(strconv.FormatFloat(n, 'f', -1, 64)), nil
 }
 
diff --git a/zero/float_test.go b/zero/float_test.go
index 9b94cff..6c30ee1 100644
--- a/zero/float_test.go
+++ b/zero/float_test.go
@@ -2,6 +2,7 @@ package zero
 
 import (
 	"encoding/json"
+	"math"
 	"testing"
 )
 
@@ -176,6 +177,20 @@ func TestFloatScan(t *testing.T) {
 	assertNullFloat(t, null, "scanned null")
 }
 
+func TestFloatInfNaN(t *testing.T) {
+	nan := NewFloat(math.NaN(), true)
+	_, err := nan.MarshalJSON()
+	if err == nil {
+		t.Error("expected error for NaN, got nil")
+	}
+
+	inf := NewFloat(math.Inf(1), true)
+	_, err = inf.MarshalJSON()
+	if err == nil {
+		t.Error("expected error for Inf, got nil")
+	}
+}
+
 func assertFloat(t *testing.T, f Float, from string) {
 	if f.Float64 != 1.2345 {
 		t.Errorf("bad %s float: %f ≠ %f\n", from, f.Float64, 1.2345)