Fix decoding of heterogeneous enums.

multiversx · May 16, 2024 · fc4d051 · fc4d051
1 parent 821793e
commit fc4d051
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Showing 3 changed files with 133 additions and 79 deletions.
diff --git a/abi/codecForEnum.go b/abi/codecForEnum.go
@@ -2,14 +2,16 @@ package abi
 
 import (
 	"bytes"
+	"errors"
 	"fmt"
 	"io"
 )
 
 // EnumValue is an enum (discriminant and fields)
 type EnumValue struct {
-	Discriminant uint8
-	Fields       []Field
+	Discriminant   uint8
+	Fields         []Field
+	FieldsProvider func(uint8) []Field
 }
 
 // EncodeNested encodes the value in the nested form
@@ -42,13 +44,18 @@ func (value *EnumValue) EncodeTopLevel(writer io.Writer) error {
 
 // DecodeNested decodes the value from the nested form
 func (value *EnumValue) DecodeNested(reader io.Reader) error {
+	if value.FieldsProvider == nil {
+		return errors.New("cannot decode enum: fields provider is nil")
+	}
+
 	discriminant := &U8Value{}
 	err := discriminant.DecodeNested(reader)
 	if err != nil {
 		return err
 	}
 
 	value.Discriminant = discriminant.Value
+	value.Fields = value.FieldsProvider(value.Discriminant)
 
 	for _, field := range value.Fields {
 		err := field.Value.DecodeNested(reader)

diff --git a/abi/codecForEnum_test.go b/abi/codecForEnum_test.go
@@ -1,7 +1,10 @@
 package abi
 
 import (
+	"encoding/hex"
 	"testing"
+
+	"github.com/stretchr/testify/require"
 )
 
 func TestEnumValue(t *testing.T) {
@@ -69,89 +72,127 @@ func TestEnumValue(t *testing.T) {
 		)
 	})
 
-	t.Run("should decode nested", func(t *testing.T) {
-		testDecodeNested(t, codec,
-			"00",
-			&EnumValue{},
-			&EnumValue{
-				Discriminant: 0x00,
+	t.Run("should decode nested (simple)", func(t *testing.T) {
+		data, _ := hex.DecodeString("2a")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return nil
 			},
-		)
+		}
 
-		testDecodeNested(t, codec,
-			"2a",
-			&EnumValue{},
-			&EnumValue{
-				Discriminant: 42,
+		err := codec.DecodeNested(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(42), destination.Discriminant)
+		require.Empty(t, destination.Fields)
+	})
+
+	t.Run("should decode nested (simple, zero)", func(t *testing.T) {
+		data, _ := hex.DecodeString("00")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return nil
 			},
-		)
+		}
 
-		testDecodeNested(t, codec,
-			"01014142",
-			&EnumValue{
-				Fields: []Field{
+		err := codec.DecodeNested(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(0), destination.Discriminant)
+		require.Empty(t, destination.Fields)
+	})
+
+	t.Run("should decode nested (heterogeneous)", func(t *testing.T) {
+		data, _ := hex.DecodeString("01014142")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return []Field{
 					{
 						Value: &U8Value{},
 					},
 					{
 						Value: &U16Value{},
 					},
-				},
+				}
 			},
-			&EnumValue{
-				Discriminant: 0x01,
-				Fields: []Field{
-					{
-						Value: &U8Value{Value: 0x01},
-					},
-					{
-						Value: &U16Value{Value: 0x4142},
-					},
+		}
+
+		err := codec.DecodeNested(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(1), destination.Discriminant)
+		require.Equal(t,
+			[]Field{
+				{
+					Value: &U8Value{Value: 0x01},
+				},
+				{
+					Value: &U16Value{Value: 0x4142},
 				},
 			},
+			destination.Fields,
 		)
 	})
 
-	t.Run("should decode top-level", func(t *testing.T) {
-		testDecodeTopLevel(t, codec,
-			"",
-			&EnumValue{},
-			&EnumValue{
-				Discriminant: 0x00,
+	t.Run("should decode top-level (simple)", func(t *testing.T) {
+		data, _ := hex.DecodeString("2a")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return nil
 			},
-		)
+		}
 
-		testDecodeTopLevel(t, codec,
-			"2a",
-			&EnumValue{},
-			&EnumValue{
-				Discriminant: 42,
+		err := codec.DecodeTopLevel(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(42), destination.Discriminant)
+		require.Empty(t, destination.Fields)
+	})
+
+	t.Run("should decode top-level (simple, zero)", func(t *testing.T) {
+		data, _ := hex.DecodeString("")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return nil
 			},
-		)
+		}
 
-		testDecodeTopLevel(t, codec,
-			"01014142",
-			&EnumValue{
-				Fields: []Field{
+		err := codec.DecodeTopLevel(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(0), destination.Discriminant)
+		require.Empty(t, destination.Fields)
+	})
+
+	t.Run("should decode top-level (heterogeneous)", func(t *testing.T) {
+		data, _ := hex.DecodeString("01014142")
+
+		destination := &EnumValue{
+			FieldsProvider: func(discriminant uint8) []Field {
+				return []Field{
 					{
 						Value: &U8Value{},
 					},
 					{
 						Value: &U16Value{},
 					},
-				},
+				}
 			},
-			&EnumValue{
-				Discriminant: 0x01,
-				Fields: []Field{
-					{
-						Value: &U8Value{Value: 0x01},
-					},
-					{
-						Value: &U16Value{Value: 0x4142},
-					},
+		}
+
+		err := codec.DecodeNested(data, destination)
+		require.NoError(t, err)
+		require.Equal(t, uint8(1), destination.Discriminant)
+		require.Equal(t,
+			[]Field{
+				{
+					Value: &U8Value{Value: 0x01},
+				},
+				{
+					Value: &U16Value{Value: 0x4142},
 				},
 			},
+			destination.Fields,
 		)
 	})
 }
diff --git a/abi/serializer_test.go b/abi/serializer_test.go
@@ -552,29 +552,35 @@ func TestSerializer_InRealWorldScenarios(t *testing.T) {
 		}
 
 		action := &EnumValue{
-			Fields: []Field{
-				{
-					Name:  "to",
-					Value: actionTo,
-				},
-				{
-					Name:  "egld_amount",
-					Value: actionEgldAmount,
-				},
-				{
-					Name: "opt_gas_limit",
-					Value: &OptionValue{
-						Value: actionGasLimit,
-					},
-				},
-				{
-					Name:  "endpoint_name",
-					Value: actionEndpointName,
-				},
-				{
-					Name:  "arguments",
-					Value: actionArguments,
-				},
+			FieldsProvider: func(discriminant uint8) []Field {
+				if discriminant == 5 {
+					return []Field{
+						{
+							Name:  "to",
+							Value: actionTo,
+						},
+						{
+							Name:  "egld_amount",
+							Value: actionEgldAmount,
+						},
+						{
+							Name: "opt_gas_limit",
+							Value: &OptionValue{
+								Value: actionGasLimit,
+							},
+						},
+						{
+							Name:  "endpoint_name",
+							Value: actionEndpointName,
+						},
+						{
+							Name:  "arguments",
+							Value: actionArguments,
+						},
+					}
+				}
+
+				return nil
 			},
 		}