Add JSON unmarshallers for numeric types from util (#83)

Uint160, Uint256, Fixed8 now have UnmarshalJSON method.

VERSION

@@ -1 +1 @@
-0.44.2
+0.44.3

pkg/util/fixed8.go

@@ -2,6 +2,7 @@ package util
 
 import (
 	"bytes"
+	"encoding/json"
 	"errors"
 	"strconv"
 	"strings"
@@ -49,7 +50,8 @@ func NewFixed8(val int) Fixed8 {
 	return Fixed8(decimals * val)
 }
 
-// Fixed8DecodeString
+// Fixed8DecodeString parses s which must be a fixed point number
+// with precision up to 10^-8
 func Fixed8DecodeString(s string) (Fixed8, error) {
 	parts := strings.SplitN(s, ".", 2)
 	ip, err := strconv.Atoi(parts[0])
@@ -68,3 +70,24 @@ func Fixed8DecodeString(s string) (Fixed8, error) {
 	}
 	return Fixed8(ip*decimals + fp), nil
 }
+
+// UnmarshalJSON implements the json unmarshaller interface.
+func (f *Fixed8) UnmarshalJSON(data []byte) error {
+	var s string
+	if err := json.Unmarshal(data, &s); err == nil {
+		p, err := Fixed8DecodeString(s)
+		if err != nil {
+			return err
+		}
+		*f = p
+		return nil
+	}
+
+	var fl float64
+	if err := json.Unmarshal(data, &fl); err != nil {
+		return err
+	}
+
+	*f = Fixed8(decimals * fl)
+	return nil
+}

pkg/util/fixed8_test.go

@@ -1,6 +1,7 @@
 package util
 
 import (
+	"encoding/json"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
@@ -18,7 +19,7 @@ func TestNewFixed8(t *testing.T) {
 func TestFixed8DecodeString(t *testing.T) {
 	// Fixed8DecodeString works correctly with integers
 	ivalues := []string{"9000", "100000000", "5", "10945"}
-	for _, val:= range ivalues {
+	for _, val := range ivalues {
 		n, err := Fixed8DecodeString(val)
 		assert.Nil(t, err)
 		assert.Equal(t, val, n.String())
@@ -36,3 +37,21 @@ func TestFixed8DecodeString(t *testing.T) {
 	assert.Nil(t, err)
 	assert.Equal(t, Fixed8(90123410000), n)
 }
+
+func TestFixed8UnmarshalJSON(t *testing.T) {
+	fl := float64(123.45)
+	str := "123.45"
+	expected, _ := Fixed8DecodeString(str)
+
+	// UnmarshalJSON should decode floats
+	var u1 Fixed8
+	s, _ := json.Marshal(fl)
+	assert.Nil(t, json.Unmarshal(s, &u1))
+	assert.Equal(t, expected, u1)
+
+	// UnmarshalJSON should decode strings
+	var u2 Fixed8
+	s, _ = json.Marshal(str)
+	assert.Nil(t, json.Unmarshal(s, &u2))
+	assert.Equal(t, expected, u2)
+}

pkg/util/test_util.go

@@ -18,7 +18,7 @@ func RandomString(n int) string {
 	return string(b)
 }
 
-// RamdomInt returns a ramdom integer betweeen min and max.
+// RandomInt returns a ramdom integer betweeen min and max.
 func RandomInt(min, max int) int {
 	return min + rand.Intn(max-min)
 }

pkg/util/uint160.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"strings"
 
 	"golang.org/x/crypto/ripemd160"
 )
@@ -77,6 +78,19 @@ func (u Uint160) Equals(other Uint160) bool {
 	return true
 }
 
+// UnmarshalJSON implements the json unmarshaller interface.
+func (u *Uint160) UnmarshalJSON(data []byte) (err error) {
+	var js string
+	if err = json.Unmarshal(data, &js); err != nil {
+		return err
+	}
+	if strings.HasPrefix(js, "0x") {
+		js = js[2:]
+	}
+	*u, err = Uint160DecodeString(js)
+	return err
+}
+
 // MarshalJSON implements the json marshaller interface.
 func (u Uint160) MarshalJSON() ([]byte, error) {
 	return json.Marshal(

pkg/util/uint160_test.go

@@ -2,11 +2,29 @@ package util
 
 import (
 	"encoding/hex"
+	"encoding/json"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+func TestUint160UnmarshalJSON(t *testing.T) {
+	str := "2d3b96ae1bcc5a585e075e3b81920210dec16302"
+	expected, _ := Uint160DecodeString(str)
+
+	// UnmarshalJSON should decode hex-strings
+	var u1 Uint160
+	s, _ := json.Marshal(str)
+	assert.Nil(t, json.Unmarshal(s, &u1))
+	assert.True(t, expected.Equals(u1))
+
+	// UnmarshalJSON should decode hex-strings prefixed by 0x
+	var u2 Uint160
+	s, _ = json.Marshal("0x" + str)
+	assert.Nil(t, json.Unmarshal(s, &u2))
+	assert.True(t, expected.Equals(u2))
+}
+
 func TestUInt160DecodeString(t *testing.T) {
 	hexStr := "2d3b96ae1bcc5a585e075e3b81920210dec16302"
 	val, err := Uint160DecodeString(hexStr)

pkg/util/uint256.go

@@ -4,6 +4,7 @@ import (
 	"encoding/hex"
 	"encoding/json"
 	"fmt"
+	"strings"
 )
 
 const uint256Size = 32
@@ -59,6 +60,19 @@ func (u Uint256) String() string {
 	return hex.EncodeToString(ArrayReverse(u.Bytes()))
 }
 
+// UnmarshalJSON implements the json unmarshaller interface.
+func (u *Uint256) UnmarshalJSON(data []byte) (err error) {
+	var js string
+	if err = json.Unmarshal(data, &js); err != nil {
+		return err
+	}
+	if strings.HasPrefix(js, "0x") {
+		js = js[2:]
+	}
+	*u, err = Uint256DecodeString(js)
+	return err
+}
+
 // MarshalJSON implements the json marshaller interface.
 func (u Uint256) MarshalJSON() ([]byte, error) {
 	return json.Marshal(fmt.Sprintf("0x%s", u.String()))

pkg/util/uint256_test.go

@@ -2,11 +2,29 @@ package util
 
 import (
 	"encoding/hex"
+	"encoding/json"
 	"testing"
 
 	"github.com/stretchr/testify/assert"
 )
 
+func TestUint256UnmarshalJSON(t *testing.T) {
+	str := "f037308fa0ab18155bccfc08485468c112409ea5064595699e98c545f245f32d"
+	expected, _ := Uint256DecodeString(str)
+
+	// UnmarshalJSON should decode hex-strings
+	var u1 Uint256
+	s, _ := json.Marshal(str)
+	assert.Nil(t, json.Unmarshal(s, &u1))
+	assert.True(t, expected.Equals(u1))
+
+	// UnmarshalJSON should decode hex-strings prefixed by 0x
+	var u2 Uint256
+	s, _ = json.Marshal("0x" + str)
+	assert.Nil(t, json.Unmarshal(s, &u2))
+	assert.True(t, expected.Equals(u2))
+}
+
 func TestUint256DecodeString(t *testing.T) {
 	hexStr := "f037308fa0ab18155bccfc08485468c112409ea5064595699e98c545f245f32d"
 	val, err := Uint256DecodeString(hexStr)