reencode: Don't normalize the capitalization of \uXXXX hex escapes

2 files changed, 34 insertions, 22 deletions

diff --git a/compat/json/compat.go b/compat/json/compat.go
index d33f278..3a9bd6c 100644
--- a/compat/json/compat.go
+++ b/compat/json/compat.go
@@ -157,7 +157,7 @@ func HTMLEscape(dst *bytes.Buffer, src []byte) {
 			case lowmemjson.BackslashEscapeNone:
 				dst.WriteRune(c)
 			case lowmemjson.BackslashEscapeUnicode:
-				_ = jsonstring.WriteStringUnicodeEscape(dst, c)
+				_ = jsonstring.WriteStringUnicodeEscape(dst, c, mode)
 			default:
 				panic(fmt.Errorf("lowmemjson.EscapeHTMLSafe returned an unexpected escape mode=%d", mode))
 			}
diff --git a/compat/json/compat_test.go b/compat/json/compat_test.go
index c83ca7e..29a8b37 100644
--- a/compat/json/compat_test.go
+++ b/compat/json/compat_test.go
@@ -18,7 +18,10 @@ func TestCompatHTMLEscape(t *testing.T) {
 		Out string
 	}
 	testcases := map[string]testcase{
-		"invalid": {In: `x`, Out: `x`},
+		"invalid":   {In: `x`, Out: `x`},
+		"hex-lower": {In: `"\uabcd"`, Out: `"\uabcd"`},
+		"hex-upper": {In: `"\uABCD"`, Out: `"\uABCD"`},
+		"hex-mixed": {In: `"\uAbCd"`, Out: `"\uAbCd"`},
 	}
 	for tcName, tc := range testcases {
 		tc := tc
@@ -39,11 +42,14 @@ func TestCompatValid(t *testing.T) {
 		Exp bool
 	}
 	testcases := map[string]testcase{
-		"empty":    {In: ``, Exp: false},
-		"num":      {In: `1`, Exp: true},
-		"trunc":    {In: `{`, Exp: false},
-		"object":   {In: `{}`, Exp: true},
-		"non-utf8": {In: "\"\x85\xcd\"", Exp: false}, // https://github.com/golang/go/issues/58517
+		"empty":     {In: ``, Exp: false},
+		"num":       {In: `1`, Exp: true},
+		"trunc":     {In: `{`, Exp: false},
+		"object":    {In: `{}`, Exp: true},
+		"non-utf8":  {In: "\"\x85\xcd\"", Exp: false}, // https://github.com/golang/go/issues/58517
+		"hex-lower": {In: `"\uabcd"`, Exp: true},
+		"hex-upper": {In: `"\uABCD"`, Exp: true},
+		"hex-mixed": {In: `"\uAbCd"`, Exp: true},
 	}
 	for tcName, tc := range testcases {
 		tc := tc
@@ -64,10 +70,13 @@ func TestCompatCompact(t *testing.T) {
 		Err string
 	}
 	testcases := map[string]testcase{
-		"trunc":    {In: `{`, Out: ``, Err: `unexpected end of JSON input`},
-		"object":   {In: `{}`, Out: `{}`},
-		"non-utf8": {In: "\"\x85\xcd\"", Out: "\"\x85\xcd\""},
-		"float":    {In: `1.200e003`, Out: `1.200e003`},
+		"trunc":     {In: `{`, Out: ``, Err: `unexpected end of JSON input`},
+		"object":    {In: `{}`, Out: `{}`},
+		"non-utf8":  {In: "\"\x85\xcd\"", Out: "\"\x85\xcd\""},
+		"float":     {In: `1.200e003`, Out: `1.200e003`},
+		"hex-lower": {In: `"\uabcd"`, Out: `"\uabcd"`},
+		"hex-upper": {In: `"\uABCD"`, Out: `"\uABCD"`},
+		"hex-mixed": {In: `"\uAbCd"`, Out: `"\uAbCd"`},
 	}
 	for tcName, tc := range testcases {
 		tc := tc
@@ -94,17 +103,20 @@ func TestCompatIndent(t *testing.T) {
 		Err string
 	}
 	testcases := map[string]testcase{
-		"trunc":    {In: `{`, Out: ``, Err: `unexpected end of JSON input`},
-		"object":   {In: `{}`, Out: `{}`},
-		"non-utf8": {In: "\"\x85\xcd\"", Out: "\"\x85\xcd\""},
-		"float":    {In: `1.200e003`, Out: `1.200e003`},
-		"tailws0":  {In: `0`, Out: `0`},
-		"tailws1":  {In: `0 `, Out: `0 `},
-		"tailws2":  {In: `0  `, Out: `0  `},
-		"tailws3":  {In: "0\n", Out: "0\n"},
-		"headws1":  {In: ` 0`, Out: `0`},
-		"objws1":   {In: `{"a"  :  1}`, Out: "{\n>.\"a\": 1\n>}"},
-		"objws2":   {In: "{\"a\"\n:\n1}", Out: "{\n>.\"a\": 1\n>}"},
+		"trunc":     {In: `{`, Out: ``, Err: `unexpected end of JSON input`},
+		"object":    {In: `{}`, Out: `{}`},
+		"non-utf8":  {In: "\"\x85\xcd\"", Out: "\"\x85\xcd\""},
+		"float":     {In: `1.200e003`, Out: `1.200e003`},
+		"tailws0":   {In: `0`, Out: `0`},
+		"tailws1":   {In: `0 `, Out: `0 `},
+		"tailws2":   {In: `0  `, Out: `0  `},
+		"tailws3":   {In: "0\n", Out: "0\n"},
+		"headws1":   {In: ` 0`, Out: `0`},
+		"objws1":    {In: `{"a"  :  1}`, Out: "{\n>.\"a\": 1\n>}"},
+		"objws2":    {In: "{\"a\"\n:\n1}", Out: "{\n>.\"a\": 1\n>}"},
+		"hex-lower": {In: `"\uabcd"`, Out: `"\uabcd"`},
+		"hex-upper": {In: `"\uABCD"`, Out: `"\uABCD"`},
+		"hex-mixed": {In: `"\uAbCd"`, Out: `"\uAbCd"`},
 	}
 	for tcName, tc := range testcases {
 		tc := tc