From b6ace7d51bf18cd44105290b9e810af0fbcf2930 Mon Sep 17 00:00:00 2001
From: Tim Hockin <thockin@google.com>
Date: Fri, 14 Jul 2017 21:19:16 +0200
Subject: [PATCH] Add a fuzz test for non-JSON input

---
 unmarshal_input_test.go | 72 +++++++++++++++++++++++++++++++++++++++++
 1 file changed, 72 insertions(+)
 create mode 100644 unmarshal_input_test.go

diff --git a/unmarshal_input_test.go b/unmarshal_input_test.go
new file mode 100644
index 0000000..9d7b99c
--- /dev/null
+++ b/unmarshal_input_test.go
@@ -0,0 +1,72 @@
+package jsoniter
+
+import (
+	"encoding/json"
+	"reflect"
+	"testing"
+
+	fuzz "github.com/google/gofuzz"
+)
+
+func Test_NilInput(t *testing.T) {
+	var jb []byte // nil
+	var out string
+	err := Unmarshal(jb, &out)
+	if err == nil {
+		t.Errorf("Expected error")
+	}
+}
+
+func Test_EmptyInput(t *testing.T) {
+	jb := []byte("")
+	var out string
+	err := Unmarshal(jb, &out)
+	if err == nil {
+		t.Errorf("Expected error")
+	}
+}
+
+func Test_RandomInput_Bytes(t *testing.T) {
+	fz := fuzz.New().NilChance(0)
+	for i := 0; i < 10000; i++ {
+		var jb []byte
+		fz.Fuzz(&jb)
+		testRandomInput(t, jb)
+	}
+}
+
+func Test_RandomInput_String(t *testing.T) {
+	fz := fuzz.New().NilChance(0)
+	for i := 0; i < 10000; i++ {
+		var js string
+		fz.Fuzz(&js)
+		jb := []byte(js)
+		testRandomInput(t, jb)
+	}
+}
+
+func testRandomInput(t *testing.T, jb []byte) {
+	var outString string
+	testRandomInputTo(t, jb, &outString)
+
+	var outInt int
+	testRandomInputTo(t, jb, &outInt)
+
+	var outStruct struct{}
+	testRandomInputTo(t, jb, &outStruct)
+
+	var outSlice []string
+	testRandomInputTo(t, jb, &outSlice)
+}
+
+func testRandomInputTo(t *testing.T, jb []byte, out interface{}) {
+	err := Unmarshal(jb, out)
+	if err == nil {
+		// Cross-check stdlib to see if we just happened to fuzz a legit value.
+		err := json.Unmarshal(jb, out)
+		if err != nil {
+			t.Fatalf("Expected error unmarshaling as %s:\nas string: %q\nas bytes: %v",
+				reflect.TypeOf(out).Elem().Kind(), string(jb), jb)
+		}
+	}
+}