fix(shardid): implement json.Marshaler and json.Unmarshaler on ID (#40)

shardid/id.go

@@ -2,6 +2,7 @@ package shardid
 
 import (
 	"database/sql/driver"
+	"encoding/json"
 	"errors"
 	"time"
 )
@@ -98,3 +99,18 @@ func (b *ID) Scan(src interface{}) error { // skipcq: GO-W1029
 	b.WorkerID = id.WorkerID
 	return nil
 }
+
+// MarshalJSON implements the json.Marshaler interface
+func (id ID) MarshalJSON() ([]byte, error) {
+	return json.Marshal(id.Int64)
+}
+
+// UnmarshalJSON implements the json.Unmarshaler interface
+func (id *ID) UnmarshalJSON(data []byte) error {
+	var value int64
+	if err := json.Unmarshal(data, &value); err != nil {
+		return err
+	}
+	*id = Parse(value)
+	return nil
+}

shardid/id_test.go

@@ -2,6 +2,7 @@ package shardid
 
 import (
 	"database/sql"
+	"encoding/json"
 	"fmt"
 	"math/rand"
 	"testing"
@@ -97,7 +98,7 @@ func TestID(t *testing.T) {
 	}
 }
 
-func TestSQLDriver(t *testing.T) {
+func TestIDInSQL(t *testing.T) {
 	d, err := sql.Open("sqlite3", "file::memory:")
 	require.NoError(t, err)
 
@@ -127,3 +128,29 @@ func TestSQLDriver(t *testing.T) {
 	require.Equal(t, id.WorkerID, i.WorkerID)
 
 }
+
+func TestIdInJSON(t *testing.T) {
+
+	now := time.Now()
+	id := Build(now.UnixMilli(), 1, 2, MonthlyRotate, 3)
+
+	idInt64 := id.Int64
+
+	bufID, err := json.Marshal(id)
+	require.NoError(t, err)
+
+	bufIdInt64, err := json.Marshal(idInt64)
+	require.NoError(t, err)
+
+	require.Equal(t, bufIdInt64, bufID)
+
+	var jsID ID
+	err = json.Unmarshal(bufIdInt64, &jsID)
+	require.NoError(t, err)
+	require.Equal(t, id, jsID)
+
+	var jsIdInt64 int64
+	err = json.Unmarshal(bufID, &jsIdInt64)
+	require.NoError(t, err)
+	require.Equal(t, idInt64, jsIdInt64)
+}