Enhancement: JSON Marshalling of *bscript.Script (#85)

* added json marshal and unmarshal funcs

* fixed unmarshalling

* changed out to a pointer in tests

bscript/script.go

@@ -5,6 +5,7 @@ import (
 	"crypto/rand"
 	"encoding/binary"
 	"encoding/hex"
+	"fmt"
 	"strings"
 
 	"github.com/libsv/go-bk/bec"
@@ -394,3 +395,19 @@ func (s *Script) EqualsBytes(b []byte) bool {
 func (s *Script) EqualsHex(h string) bool {
 	return s.String() == h
 }
+
+// MarshalJSON convert script into json.
+func (s *Script) MarshalJSON() ([]byte, error) {
+	return []byte(fmt.Sprintf(`"%s"`, s.String())), nil
+}
+
+// UnmarshalJSON covert from json into *bscript.Script.
+func (s *Script) UnmarshalJSON(bb []byte) error {
+	ss, err := NewFromHexString(string(bytes.Trim(bb, `"`)))
+	if err != nil {
+		return err
+	}
+
+	*s = *ss
+	return nil
+}

bscript/script_test.go

@@ -3,6 +3,7 @@ package bscript_test
 import (
 	"crypto/rand"
 	"encoding/hex"
+	"encoding/json"
 	"strings"
 	"testing"
 
@@ -288,3 +289,37 @@ func TestScript_Equals(t *testing.T) {
 		})
 	}
 }
+
+func TestScript_MarshalJSON(t *testing.T) {
+	script, err := bscript.NewFromASM("OP_2 OP_2 OP_ADD OP_4 OP_EQUALVERIFY")
+	assert.NoError(t, err)
+
+	bb, err := json.Marshal(script)
+	assert.NoError(t, err)
+
+	assert.Equal(t, `"5252935488"`, string(bb))
+}
+
+func TestScript_UnmarshalJSON(t *testing.T) {
+	tests := map[string]struct {
+		jsonString string
+		exp        string
+	}{
+		"script with content": {
+			jsonString: `"5252935488"`,
+			exp:        "5252935488",
+		},
+		"empty script": {
+			jsonString: `""`,
+			exp:        "",
+		},
+	}
+
+	for name, test := range tests {
+		t.Run(name, func(t *testing.T) {
+			var out *bscript.Script
+			assert.NoError(t, json.Unmarshal([]byte(test.jsonString), &out))
+			assert.Equal(t, test.exp, out.String())
+		})
+	}
+}