[tests] added tests for key text marshaler

Makefile

@@ -26,7 +26,7 @@ generate: root build
 		.root/src/$(PKG)/tests/named_type.go \
 		.root/src/$(PKG)/tests/custom_map_key_type.go \
 		.root/src/$(PKG)/tests/embedded_type.go \
-		.root/src/$(PKG)/tests/reference_to_pointer.go
+		.root/src/$(PKG)/tests/reference_to_pointer.go \
 
 	.root/bin/easyjson -all .root/src/$(PKG)/tests/data.go
 	.root/bin/easyjson -all .root/src/$(PKG)/tests/nothing.go
@@ -39,6 +39,7 @@ generate: root build
 	.root/bin/easyjson .root/src/$(PKG)/tests/custom_map_key_type.go
 	.root/bin/easyjson .root/src/$(PKG)/tests/embedded_type.go
 	.root/bin/easyjson .root/src/$(PKG)/tests/reference_to_pointer.go
+	.root/bin/easyjson .root/src/$(PKG)/tests/key_marshaler_map.go
 	.root/bin/easyjson -disallow_unknown_fields .root/src/$(PKG)/tests/disallow_unknown.go
 
 test: generate root

tests/basic_test.go

@@ -52,6 +52,7 @@ var testCases = []struct {
 	{&intArrayStructValue, intArrayStructValueString},
 	{&myUInt8SliceValue, myUInt8SliceString},
 	{&myUInt8ArrayValue, myUInt8ArrayString},
+	{&mapWithEncodingMarshaler, mapWithEncodingMarshalerString},
 }
 
 func TestMarshal(t *testing.T) {

tests/key_marshaler_map.go

@@ -0,0 +1,20 @@
+package tests
+
+type KeyWithEncodingMarshaler int
+
+func (f KeyWithEncodingMarshaler) MarshalText() (text []byte, err error) {
+	return []byte("hello"), nil
+}
+
+func (f *KeyWithEncodingMarshaler) UnmarshalText(text []byte) error {
+	if string(text) == "hello" {
+		*f = 5
+	}
+	return nil
+}
+
+//easyjson:json
+type KeyWithEncodingMarshalers map[KeyWithEncodingMarshaler]string
+
+var mapWithEncodingMarshaler KeyWithEncodingMarshalers = KeyWithEncodingMarshalers{5: "hello"}
+var mapWithEncodingMarshalerString = `{"hello":"hello"}`