From 25331060ec59089b589ec5d73d33423bd597cfe5 Mon Sep 17 00:00:00 2001
From: Shunsuke Suzuki <suzuki.shunsuke.1989@gmail.com>
Date: Sun, 21 Feb 2021 22:34:16 +0900
Subject: [PATCH] feat: remove ConvertByte and change signature of Convert

BREAKING CHANGE: remove ConvertByte and change signature of Convert
---
 dataeq/dataeq.go      | 30 +++++++--------------
 dataeq/dataeq_test.go | 63 +++++--------------------------------------
 dataeq/doc.go         |  2 +-
 3 files changed, 18 insertions(+), 77 deletions(-)

diff --git a/dataeq/dataeq.go b/dataeq/dataeq.go
index f69b03e..ecd1f67 100644
--- a/dataeq/dataeq.go
+++ b/dataeq/dataeq.go
@@ -28,40 +28,30 @@ func New(marshal Marshal, unmarshal Unmarshal) DataFormat {
 	}
 }
 
-// ConvertByte unmarshals a byte string to `interface{}`.
-func (df DataFormat) ConvertByte(b []byte) (interface{}, error) {
-	var d interface{}
-	err := df.unmarshal(b, &d)
-	if err == nil {
-		return d, nil
-	}
-	return nil, err
-}
-
-// Convert converts value to byte string and unmarshals the byte string to `interface{}`.
+// Convert converts value to byte string and unmarshals the byte string to dst.
 // Convert can be used to normalize the value to compare with the other value.
-func (df DataFormat) Convert(x interface{}) (interface{}, error) {
+func (df *DataFormat) Convert(x interface{}, dst interface{}) error {
 	if a, ok := x.([]byte); ok {
-		return df.ConvertByte(a)
+		return df.unmarshal(a, dst)
 	}
 	b, err := df.marshal(x)
 	if err != nil {
-		return nil, err
+		return err
 	}
-	return df.ConvertByte(b)
+	return df.unmarshal(b, dst)
 }
 
 // Equal returns true if two arguments are equal.
-func (df DataFormat) Equal(x, y interface{}) (bool, error) {
+func (df *DataFormat) Equal(x, y interface{}) (bool, error) {
 	if reflect.DeepEqual(x, y) {
 		return true, nil
 	}
-	a, err := df.Convert(x)
-	if err != nil {
+	var a interface{}
+	if err := df.Convert(x, &a); err != nil {
 		return false, err
 	}
-	b, err := df.Convert(y)
-	if err != nil {
+	var b interface{}
+	if err := df.Convert(y, &b); err != nil {
 		return false, err
 	}
 	return reflect.DeepEqual(a, b), nil
diff --git a/dataeq/dataeq_test.go b/dataeq/dataeq_test.go
index dce42f3..54f0186 100644
--- a/dataeq/dataeq_test.go
+++ b/dataeq/dataeq_test.go
@@ -8,60 +8,6 @@ import (
 	"github.com/suzuki-shunsuke/go-dataeq/dataeq"
 )
 
-func TestJSON_ConvertByte(t *testing.T) {
-	data := []struct {
-		title   string
-		b       []byte
-		isError bool
-		exp     interface{}
-	}{
-		{
-			title: "simple map",
-			b:     []byte(`{"foo": "bar"}`),
-			exp: map[string]interface{}{
-				"foo": "bar",
-			},
-		},
-		{
-			title: "simple array",
-			b:     []byte(`["foo", "bar"]`),
-			exp:   []interface{}{"foo", "bar"},
-		},
-		{
-			title: "simple int",
-			b:     []byte(`5`),
-			exp:   float64(5),
-		},
-		{
-			title: "simple string",
-			b:     []byte(`"hello"`),
-			exp:   "hello",
-		},
-		{
-			title: "simple null",
-			b:     []byte(`null`),
-			exp:   nil,
-		},
-		{
-			title:   "invalid JSON",
-			b:       []byte(`foo bar`),
-			isError: true,
-		},
-	}
-	for _, d := range data {
-		d := d
-		t.Run(d.title, func(t *testing.T) {
-			a, err := dataeq.JSON.ConvertByte(d.b)
-			if d.isError {
-				require.NotNil(t, err)
-				return
-			}
-			require.Nil(t, err)
-			require.Equal(t, d.exp, a)
-		})
-	}
-}
-
 type (
 	invalidMarshaler struct{}
 )
@@ -71,6 +17,7 @@ func (m *invalidMarshaler) MarshalJSON() ([]byte, error) {
 }
 
 func TestJSON_Convert(t *testing.T) {
+	t.Parallel()
 	data := []struct {
 		title   string
 		x       interface{}
@@ -108,7 +55,9 @@ func TestJSON_Convert(t *testing.T) {
 	for _, d := range data {
 		d := d
 		t.Run(d.title, func(t *testing.T) {
-			a, err := dataeq.JSON.Convert(d.x)
+			t.Parallel()
+			var a interface{}
+			err := dataeq.JSON.Convert(d.x, &a)
 			if d.isError {
 				require.NotNil(t, err)
 				return
@@ -119,7 +68,8 @@ func TestJSON_Convert(t *testing.T) {
 	}
 }
 
-func TestJSON_Equal(t *testing.T) {
+func TestJSON_Equal(t *testing.T) { //nolint:funlen
+	t.Parallel()
 	data := []struct {
 		title   string
 		x       interface{}
@@ -167,6 +117,7 @@ func TestJSON_Equal(t *testing.T) {
 	for _, d := range data {
 		d := d
 		t.Run(d.title, func(t *testing.T) {
+			t.Parallel()
 			f, err := dataeq.JSON.Equal(d.x, d.y)
 			if d.isError {
 				require.NotNil(t, err)
diff --git a/dataeq/doc.go b/dataeq/doc.go
index 767c87b..0e58c30 100644
--- a/dataeq/doc.go
+++ b/dataeq/doc.go
@@ -1,5 +1,5 @@
 // Package dataeq allows to create API to compare two values as the data format such as JSON and YAML.
-// dataeq compare two values by the followin way.
+// dataeq compare two values by the following way.
 //
 // 1. convert value to a byte string by Marshal
 // 2. unmarshal a byte string to `interface{}` by Unmarshal