tests(erc20): add erc20 query tests

CHANGELOG.md

@@ -80,6 +80,7 @@ Ref: https://keepachangelog.com/en/1.0.0/
 - (osmosis-outpost) [#2011](https://github.com/evmos/evmos/pull/2011) Update outpost swap ABI to return IBC next sequence.
 - (utils) [#2010](https://github.com/evmos/evmos/pull/2010) Add utils function to create ibc denom trace.
 - (osmosis-outpost) [#2017](https://github.com/evmos/evmos/pull/2017) Refactor types, errors and precompile struct.
+- (erc20) [#2023](https://github.com/evmos/evmos/pull/2023) Add tests for ERC20 precompile queries.
 
 ### Bug Fixes
 

precompiles/erc20/query.go

@@ -15,7 +15,7 @@ import (
 	authzkeeper "github.com/cosmos/cosmos-sdk/x/authz/keeper"
 	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
 	transfertypes "github.com/cosmos/ibc-go/v7/modules/apps/transfer/types"
-	"github.com/evmos/evmos/v15/precompiles/authorization"
+	auth "github.com/evmos/evmos/v15/precompiles/authorization"
 	transferkeeper "github.com/evmos/evmos/v15/x/ibc/transfer/keeper"
 
 	"github.com/ethereum/go-ethereum/accounts/abi"
@@ -51,26 +51,42 @@ func (p Precompile) Name(
 	method *abi.Method,
 	_ []interface{},
 ) ([]byte, error) {
+	// TODO: is this actually necessary here? It won't be possible to register a token
+	// with an empty denomination right? So calling this with an empty denom also won't happen..
+	if p.tokenPair.Denom == "" {
+		return nil, errors.New("denom cannot be empty")
+	}
+
 	metadata, found := p.bankKeeper.GetDenomMetaData(ctx, p.tokenPair.Denom)
 	if found {
 		return method.Outputs.Pack(metadata.Name)
 	}
 
+	baseDenom, err := p.getBaseDenomFromIBCVoucher(ctx, p.tokenPair.Denom)
+	if err != nil {
+		return nil, err
+	}
+
+	name := strings.ToUpper(string(baseDenom[1])) + baseDenom[2:]
+	return method.Outputs.Pack(name)
+}
+
+// getBaseDenom returns the base denomination from the given IBC voucher denomination.
+func (p Precompile) getBaseDenomFromIBCVoucher(ctx sdk.Context, denom string) (string, error) {
 	// Infer the denomination name from the coin denomination base denom
-	denomTrace, err := GetDenomTrace(p.transferKeeper, ctx, p.tokenPair.Denom)
+	denomTrace, err := GetDenomTrace(p.transferKeeper, ctx, denom)
 	if err != nil {
 		// FIXME: return 'not supported' (same error as when you call the method on an ERC20.sol)
-		return nil, err
+		return "", err
 	}
 
 	// safety check
 	if len(denomTrace.BaseDenom) < 3 {
 		// FIXME: return not supported (same error as when you call the method on an ERC20.sol)
-		return nil, nil
+		return "", fmt.Errorf("invalid base denomination; should be at least length 3; got: %q", denomTrace.BaseDenom)
 	}
 
-	name := strings.ToUpper(string(denomTrace.BaseDenom[1])) + denomTrace.BaseDenom[2:]
-	return method.Outputs.Pack(name)
+	return denomTrace.BaseDenom, nil
 }
 
 // Symbol returns the symbol of the token. If the token metadata is registered in the
@@ -83,6 +99,12 @@ func (p Precompile) Symbol(
 	method *abi.Method,
 	_ []interface{},
 ) ([]byte, error) {
+	// TODO: added this check here, do we want that? It won't be possible to register a token
+	// with an empty denomination right? So calling this with an empty denom also won't happen..
+	if p.tokenPair.Denom == "" {
+		return nil, errors.New("denom cannot be empty")
+	}
+
 	metadata, found := p.bankKeeper.GetDenomMetaData(ctx, p.tokenPair.Denom)
 	if found {
 		return method.Outputs.Pack(metadata.Symbol)
@@ -97,7 +119,7 @@ func (p Precompile) Symbol(
 	// safety check
 	if len(denomTrace.BaseDenom) < 3 {
 		// FIXME: return not supported (same error as when you call the method on an ERC20.sol)
-		return nil, nil
+		return nil, fmt.Errorf("invalid base denomination; should be at least length 3; got: %q", denomTrace.BaseDenom)
 	}
 
 	symbol := strings.ToUpper(denomTrace.BaseDenom[1:])
@@ -130,11 +152,15 @@ func (p Precompile) Decimals(
 			return method.Outputs.Pack(uint8(18))
 		}
 		// FIXME: return not supported (same error as when you call the method on an ERC20.sol)
-		return nil, nil
+		return nil, fmt.Errorf(
+			"invalid base denomination; should be either micro ('u[...]') or atto ('a[...]'); got: %q",
+			denomTrace.BaseDenom,
+		)
 	}
 
 	var decimals uint32
-	for i := len(metadata.DenomUnits); i >= 0; i-- {
+	for i := len(metadata.DenomUnits) - 1; i >= 0; i-- {
+		// TODO: return error here if display denom is not found?
 		if metadata.DenomUnits[i].Denom == metadata.Display {
 			decimals = metadata.DenomUnits[i].Exponent
 			break
@@ -145,7 +171,7 @@ func (p Precompile) Decimals(
 		return nil, errors.New("uint8 overflow: invalid decimals")
 	}
 
-	return method.Outputs.Pack(uint8(decimals)) //#nosec G701
+	return method.Outputs.Pack(uint8(decimals)) //#nosec G701 // we are checking for overflow above
 }
 
 // TotalSupply returns the amount of tokens in existence. It fetches the supply
@@ -238,7 +264,7 @@ func GetAuthzAndAllowance(
 	grantee, granter common.Address,
 	denom string,
 ) (authz.Authorization, *big.Int, error) {
-	authorization, _, err := authorization.CheckAuthzExists(ctx, authzKeeper, grantee, granter, SendMsgURL)
+	authorization, _, err := auth.CheckAuthzExists(ctx, authzKeeper, grantee, granter, SendMsgURL)
 	// TODO: return error if doesn't exist?
 	if err != nil {
 		return nil, common.Big0, err