From 2ea6ed0ea8d20091ff80b30ab47e206e776e7c53 Mon Sep 17 00:00:00 2001
From: Victor Starodub <vstarodub@users.noreply.github.com>
Date: Fri, 7 Oct 2016 15:52:17 +0300
Subject: [PATCH] Allow marshalling "named" maps.

---
 gen/decoder.go      | 14 +++++++++-----
 gen/encoder.go      | 20 ++++++++++++--------
 tests/basic_test.go |  1 +
 tests/data.go       |  7 +++++++
 4 files changed, 29 insertions(+), 13 deletions(-)

diff --git a/gen/decoder.go b/gen/decoder.go
index 0688e5d..681584f 100644
--- a/gen/decoder.go
+++ b/gen/decoder.go
@@ -322,7 +322,7 @@ func getStructFields(t reflect.Type) ([]reflect.StructField, error) {
 
 func (g *Generator) genDecoder(t reflect.Type) error {
 	switch t.Kind() {
-	case reflect.Slice, reflect.Array:
+	case reflect.Slice, reflect.Array, reflect.Map:
 		return g.genSliceArrayDecoder(t)
 	default:
 		return g.genStructDecoder(t)
@@ -330,8 +330,10 @@ func (g *Generator) genDecoder(t reflect.Type) error {
 }
 
 func (g *Generator) genSliceArrayDecoder(t reflect.Type) error {
-	if t.Kind() != reflect.Slice && t.Kind() != reflect.Array {
-		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice or array type", t)
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice/array/map type", t)
 	}
 
 	fname := g.getDecoderName(t)
@@ -413,8 +415,10 @@ func (g *Generator) genStructDecoder(t reflect.Type) error {
 }
 
 func (g *Generator) genStructUnmarshaller(t reflect.Type) error {
-	if t.Kind() != reflect.Struct && t.Kind() != reflect.Slice && t.Kind() != reflect.Array {
-		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array type", t)
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map, reflect.Struct:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array/map type", t)
 	}
 
 	fname := g.getDecoderName(t)
diff --git a/gen/encoder.go b/gen/encoder.go
index ba9053f..06303e0 100644
--- a/gen/encoder.go
+++ b/gen/encoder.go
@@ -266,16 +266,18 @@ func (g *Generator) genStructFieldEncoder(t reflect.Type, f reflect.StructField)
 
 func (g *Generator) genEncoder(t reflect.Type) error {
 	switch t.Kind() {
-	case reflect.Slice, reflect.Array:
-		return g.genSliceArrayEncoder(t)
+	case reflect.Slice, reflect.Array, reflect.Map:
+		return g.genSliceArrayMapEncoder(t)
 	default:
 		return g.genStructEncoder(t)
 	}
 }
 
-func (g *Generator) genSliceArrayEncoder(t reflect.Type) error {
-	if t.Kind() != reflect.Slice && t.Kind() != reflect.Array {
-		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice or array type", t)
+func (g *Generator) genSliceArrayMapEncoder(t reflect.Type) error {
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a slice/array/map type", t)
 	}
 
 	fname := g.getEncoderName(t)
@@ -292,7 +294,7 @@ func (g *Generator) genSliceArrayEncoder(t reflect.Type) error {
 
 func (g *Generator) genStructEncoder(t reflect.Type) error {
 	if t.Kind() != reflect.Struct {
-		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct type")
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct type", t)
 	}
 
 	fname := g.getEncoderName(t)
@@ -320,8 +322,10 @@ func (g *Generator) genStructEncoder(t reflect.Type) error {
 }
 
 func (g *Generator) genStructMarshaller(t reflect.Type) error {
-	if t.Kind() != reflect.Struct && t.Kind() != reflect.Slice && t.Kind() != reflect.Array {
-		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array type", t)
+	switch t.Kind() {
+	case reflect.Slice, reflect.Array, reflect.Map, reflect.Struct:
+	default:
+		return fmt.Errorf("cannot generate encoder/decoder for %v, not a struct/slice/array/map type", t)
 	}
 
 	fname := g.getEncoderName(t)
diff --git a/tests/basic_test.go b/tests/basic_test.go
index a5d6236..3e994ea 100644
--- a/tests/basic_test.go
+++ b/tests/basic_test.go
@@ -35,6 +35,7 @@ var testCases = []struct {
 	{&mapsValue, mapsString},
 	{&deepNestValue, deepNestString},
 	{&IntsValue, IntsString},
+	{&mapStringStringValue, mapStringStringString},
 }
 
 func TestMarshal(t *testing.T) {
diff --git a/tests/data.go b/tests/data.go
index 0fe15d5..1716617 100644
--- a/tests/data.go
+++ b/tests/data.go
@@ -613,6 +613,13 @@ var IntsValue = Ints{1, 2, 3, 4, 5}
 
 var IntsString = `[1,2,3,4,5]`
 
+//easyjson:json
+type MapStringString map[string]string
+
+var mapStringStringValue = MapStringString{"a": "b"}
+
+var mapStringStringString = `{"a":"b"}`
+
 type RequiredOptionalStruct struct {
 	FirstName string `json:"first_name,required"`
 	Lastname  string `json:"last_name"`