Fixed encoding of optional primitive types as well as *Uint64 types

Fixes #140

CHANGELOG.md

@@ -15,6 +15,10 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 - Added `ActionTrace.ContextFree` field of type `bool` that was previously missing from the struct definition.
 
 ### Fixed
+- Optional encoding of primitive types.
+
+  A struct with a non-pointer type tagged with `eos:"optional"` is now properly encoded at the binary level. **Important** that means that for non-pointer type, when the value of the type is the "emtpy" value according to Golang rules, it will be written as not-present at the binary level. If it's something that you do want want, use a pointer to a primitive type. It's actually a good habit to use a pointer type for "optional" element anyway, to increase awarness.
+
 - Fix json tags for delegatebw action data.
 - Unpacking binary `Except` now correctly works.
 - Unpacking binary `Action` and `ActionTrace` now correctly works.

encoder.go

@@ -20,7 +20,7 @@ import (
 //
 // **Warning** This is experimental, exposed only for internal usage for now.
 type MarshalerBinary interface {
-	MarshalerBinary(encoder *Encoder) error
+	MarshalBinary(encoder *Encoder) error
 }
 
 func MarshalBinary(v interface{}) ([]byte, error) {
@@ -58,7 +58,7 @@ func (e *Encoder) writeName(name Name) error {
 func (e *Encoder) Encode(v interface{}) (err error) {
 	switch cv := v.(type) {
 	case MarshalerBinary:
-		return cv.MarshalerBinary(e)
+		return cv.MarshalBinary(e)
 	case BaseVariant:
 		err = e.writeUVarInt(int(cv.TypeID))
 		if err != nil {
@@ -108,8 +108,6 @@ func (e *Encoder) Encode(v interface{}) (err error) {
 		return e.writeUint64(cv)
 	case Int64:
 		return e.writeUint64(uint64(cv))
-	case Uint64:
-		return e.writeUint64(uint64(cv))
 	case int64:
 		return e.writeInt64(cv)
 	case float32:
@@ -236,7 +234,7 @@ func (e *Encoder) Encode(v interface{}) (err error) {
 					if v.CanInterface() {
 						isPresent := true
 						if tag == "optional" {
-							isPresent = !v.IsNil()
+							isPresent = !v.IsZero()
 							e.writeBool(isPresent)
 						}
 

encoder_test.go

@@ -5,6 +5,7 @@ import (
 	"encoding/hex"
 	"testing"
 
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 )
 
@@ -29,3 +30,40 @@ func TestEncoder_MapStringString(t *testing.T) {
 		require.Fail(t, "encoded map is invalid", "must be either %q or %q, got %q", expected1, expected2, out)
 	}
 }
+
+func Test_OptionalPrimitiveType(t *testing.T) {
+	type test struct {
+		ID uint64 `eos:"optional"`
+	}
+
+	out, err := MarshalBinary(test{ID: 0})
+	require.NoError(t, err)
+
+	assert.Equal(t, []byte{0x0}, out)
+
+	out, err = MarshalBinary(test{ID: 10})
+	require.NoError(t, err)
+
+	assert.Equal(t, []byte{0x1, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, out)
+}
+
+func Test_OptionalPointerToPrimitiveType(t *testing.T) {
+	type test struct {
+		ID *Uint64 `eos:"optional"`
+	}
+
+	out, err := MarshalBinary(test{ID: nil})
+	require.NoError(t, err)
+	assert.Equal(t, []byte{0x0}, out)
+
+	id := Uint64(0)
+	out, err = MarshalBinary(test{ID: &id})
+	require.NoError(t, err)
+	assert.Equal(t, []byte{0x1, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, out)
+
+	id = Uint64(10)
+	out, err = MarshalBinary(test{ID: &id})
+	require.NoError(t, err)
+
+	assert.Equal(t, []byte{0x1, 0xa, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0, 0x0}, out)
+}

types.go

@@ -963,6 +963,10 @@ func (i *Uint64) UnmarshalJSON(data []byte) error {
 	return nil
 }
 
+func (i Uint64) MarshalBinary(encoder *Encoder) error {
+	return encoder.writeUint64(uint64(i))
+}
+
 // uint128
 type Uint128 struct {
 	Lo uint64