bugfix: Update utils.go (#530)

* Update utils.go bugfix: compare 2 DenomUnit variable wrong because they are pointers * Bugfix:fetch decimal from cosmos coin metadata decimals := uint8(coinMetadata.DenomUnits[0].Exponent) The original code maybe OK for evmos itself. However, it may causes incorrect decimal value 1. in the metadata validation func: cosmos-sdk/x/bank/types/metadata.go: Metadata.Validate() it makes sure Denomination units are sorted in ascending order. 2. https://docs.evmos.org/modules/erc20/01_concepts.html "Coin Metadata to ERC20 details" informaiton * add unit test code for compare 2 donom metadata * revise testing code Co-authored-by: Andy Wronski <[email protected]> Co-authored-by: Federico Kunze Küllmer <[email protected]>
loveFeynman · Apr 28, 2022 · 4e84ecb · 4e84ecb
1 parent 54f573e
commit 4e84ecb
Show file tree

Hide file tree

Showing 3 changed files with 113 additions and 2 deletions.
diff --git a/x/erc20/keeper/proposals.go b/x/erc20/keeper/proposals.go
@@ -73,7 +73,11 @@ func (k Keeper) DeployERC20Contract(
 	ctx sdk.Context,
 	coinMetadata banktypes.Metadata,
 ) (common.Address, error) {
-	decimals := uint8(coinMetadata.DenomUnits[0].Exponent)
+	decimals := uint8(0)
+	if len(coinMetadata.DenomUnits) > 0 {
+		decimalsIdx := len(coinMetadata.DenomUnits) - 1
+		decimals = uint8(coinMetadata.DenomUnits[decimalsIdx].Exponent)
+	}
 	ctorArgs, err := contracts.ERC20MinterBurnerDecimalsContract.ABI.Pack(
 		"",
 		coinMetadata.Name,

diff --git a/x/erc20/types/utils.go b/x/erc20/types/utils.go
@@ -2,6 +2,7 @@ package types
 
 import (
 	"fmt"
+	"sort"
 	"strings"
 
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
@@ -26,7 +27,7 @@ func EqualMetadata(a, b banktypes.Metadata) error {
 		}
 
 		for i, v := range a.DenomUnits {
-			if v != b.DenomUnits[i] {
+			if (v.Exponent != b.DenomUnits[i].Exponent) || (v.Denom != b.DenomUnits[i].Denom) || !EqualStringSlice(v.Aliases, b.DenomUnits[i].Aliases) {
 				return fmt.Errorf("metadata provided has different denom unit from stored, %s ≠ %s", a.DenomUnits[i], b.DenomUnits[i])
 			}
 		}
@@ -35,3 +36,20 @@ func EqualMetadata(a, b banktypes.Metadata) error {
 	}
 	return fmt.Errorf("metadata provided is different from stored")
 }
+
+// EqualStringSlice checks if two string slices are equal.
+func EqualStringSlice(a, b []string) bool {
+	if len(a) != len(b) {
+		return false
+	}
+
+	sort.Strings(a)
+	sort.Strings(b)
+	for idx := len(a) - 1; idx > -1; idx-- {
+		if a[idx] != b[idx] {
+			return false
+		}
+	}
+
+	return true
+}
diff --git a/x/erc20/types/utils_test.go b/x/erc20/types/utils_test.go
@@ -3,6 +3,7 @@ package types
 import (
 	"testing"
 
+	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	"github.com/stretchr/testify/require"
 )
 
@@ -25,3 +26,91 @@ func TestSanitizeERC20Name(t *testing.T) {
 		require.Equal(t, tc.expErc20Name, name, tc.name)
 	}
 }
+
+func TestEqualMetadata(t *testing.T) {
+
+	base := "CoinBase"
+	display := "CoinDisplay"
+	name := "CoinName"
+	symbol := "CoinATOM"
+	description := "ATOM Coin"
+	decimal := uint32(18)
+
+	// for metadata_A
+	denomUnits_A := []*banktypes.DenomUnit{
+		{
+			Denom:    base,
+			Exponent: 0,
+			Aliases:  []string{base, "moreInfo"},
+		},
+		{
+			Denom:    display,
+			Exponent: decimal,
+			Aliases:  []string{display, "moreInfo"},
+		}}
+	metadata_A := banktypes.Metadata{
+		Base:        base,
+		Display:     display,
+		Name:        name,
+		Symbol:      symbol,
+		Description: description,
+		DenomUnits:  denomUnits_A,
+	}
+
+	// for metadata_B
+	denomUnits_B := []*banktypes.DenomUnit{
+		{
+			Denom:    base,
+			Exponent: 0,
+			Aliases:  []string{"moreInfo", base},
+		},
+		{
+			Denom:    display,
+			Exponent: decimal,
+			Aliases:  []string{display, "moreInfo"},
+		}}
+	metadata_B := banktypes.Metadata{
+		Base:        base,
+		Display:     display,
+		Name:        name,
+		Symbol:      symbol,
+		Description: description,
+		DenomUnits:  denomUnits_B,
+	}
+
+	// for metadata_C
+	denomUnits_C := []*banktypes.DenomUnit{
+		{
+			Denom:    base,
+			Exponent: 0,
+			Aliases:  []string{"moreInfo_YES", base},
+		},
+		{
+			Denom:    display,
+			Exponent: decimal,
+			Aliases:  []string{display, "moreInfo"},
+		}}
+	metadata_C := banktypes.Metadata{
+		Base:        base,
+		Display:     display,
+		Name:        name,
+		Symbol:      symbol,
+		Description: description,
+		DenomUnits:  denomUnits_C,
+	}
+
+	// metadata list
+	metadataList := []*banktypes.Metadata{
+		&metadata_A,
+		&metadata_B,
+		&metadata_C,
+	}
+
+	// validate each metadata
+	for _, md := range metadataList {
+		require.NoError(t, md.Validate())
+	}
+
+	require.NoError(t, EqualMetadata(metadata_A, metadata_B))
+	require.NotEqual(t, EqualMetadata(metadata_A, metadata_C), nil)
+}