chore: improve unit tests

utils/mocks/aura.go

@@ -15,6 +15,10 @@ import (
 )
 
 func AuraKeeper(t testing.TB) (*keeper.Keeper, sdk.Context) {
+	return AuraKeeperWithBank(t, BankKeeper{})
+}
+
+func AuraKeeperWithBank(t testing.TB, bank types.BankKeeper) (*keeper.Keeper, sdk.Context) {
 	logger := log.NewNopLogger()
 
 	key := storetypes.NewKVStoreKey(types.ModuleName)
@@ -28,6 +32,6 @@ func AuraKeeper(t testing.TB) (*keeper.Keeper, sdk.Context) {
 		runtime.ProvideEventService(),
 		"ausdy",
 		AccountKeeper{},
-		BankKeeper{},
+		bank,
 	), wrapper.Ctx
 }

utils/mocks/bank.go

@@ -3,26 +3,65 @@ package mocks
 import (
 	"context"
 
+	sdkerrors "cosmossdk.io/errors"
 	sdk "github.com/cosmos/cosmos-sdk/types"
+	"github.com/cosmos/cosmos-sdk/types/errors"
+	"github.com/cosmos/cosmos-sdk/x/auth/codec"
 	"github.com/noble-assets/aura/x/aura/types"
 )
 
+var cdc = codec.NewBech32Codec("noble")
+
 var _ types.BankKeeper = BankKeeper{}
 
-type BankKeeper struct{}
+type BankKeeper struct {
+	Balances map[string]sdk.Coins
+}
 
 func (k BankKeeper) BurnCoins(ctx context.Context, moduleName string, amt sdk.Coins) error {
+	balance := k.Balances[moduleName]
+	newBalance, negative := balance.SafeSub(amt...)
+	if negative {
+		return sdkerrors.Wrapf(errors.ErrInsufficientFunds, "spendable balance %s is smaller than %s", balance, amt)
+	}
+
+	k.Balances[moduleName] = newBalance
+
 	return nil
 }
 
 func (k BankKeeper) MintCoins(ctx context.Context, moduleName string, amt sdk.Coins) error {
+	k.Balances[moduleName] = k.Balances[moduleName].Add(amt...)
+
 	return nil
 }
 
 func (k BankKeeper) SendCoinsFromAccountToModule(ctx context.Context, senderAddr sdk.AccAddress, recipientModule string, amt sdk.Coins) error {
+	sender, _ := cdc.BytesToString(senderAddr)
+
+	balance := k.Balances[sender]
+	newBalance, negative := balance.SafeSub(amt...)
+	if negative {
+		return sdkerrors.Wrapf(errors.ErrInsufficientFunds, "spendable balance %s is smaller than %s", balance, amt)
+	}
+
+	k.Balances[sender] = newBalance
+	k.Balances[recipientModule] = k.Balances[recipientModule].Add(amt...)
+
 	return nil
 }
 
 func (k BankKeeper) SendCoinsFromModuleToAccount(ctx context.Context, senderModule string, recipientAddr sdk.AccAddress, amt sdk.Coins) error {
+	recipient, _ := cdc.BytesToString(recipientAddr)
+
+	balance := k.Balances[senderModule]
+	newBalance, negative := balance.SafeSub(amt...)
+	if negative {
+		return sdkerrors.Wrapf(errors.ErrInsufficientFunds, "spendable balance %s is smaller than %s", balance, amt)
+	}
+
+	k.Balances[senderModule] = newBalance
+	k.Balances[recipient] = k.Balances[recipient].Add(amt...)
+
 	return nil
 }

x/aura/keeper/msg_server_test.go

@@ -3,13 +3,111 @@ package keeper_test
 import (
 	"testing"
 
+	"cosmossdk.io/math"
+	sdk "github.com/cosmos/cosmos-sdk/types"
 	"github.com/noble-assets/aura/utils"
 	"github.com/noble-assets/aura/utils/mocks"
 	"github.com/noble-assets/aura/x/aura/keeper"
 	"github.com/noble-assets/aura/x/aura/types"
 	"github.com/stretchr/testify/require"
 )
 
+var ONE = math.NewInt(1_000_000_000_000_000_000)
+
+func TestBurn(t *testing.T) {
+	bank := mocks.BankKeeper{
+		Balances: make(map[string]sdk.Coins),
+	}
+	k, ctx := mocks.AuraKeeperWithBank(t, bank)
+	server := keeper.NewMsgServer(k)
+
+	// ARRANGE: Set burner in state.
+	burner := utils.TestAccount()
+	require.NoError(t, k.Burners.Set(ctx, burner.Address))
+
+	// ACT: Attempt to burn with invalid signer.
+	_, err := server.Burn(ctx, &types.MsgBurn{
+		Signer: utils.TestAccount().Address,
+	})
+	// ASSERT: The action should've failed due to invalid signer.
+	require.ErrorContains(t, err, types.ErrInvalidBurner.Error())
+
+	// ACT: Attempt to burn with invalid account address.
+	_, err = server.Burn(ctx, &types.MsgBurn{
+		Signer: burner.Address,
+		From:   "cosmos10d07y265gmmuvt4z0w9aw880jnsr700j6zn9kn",
+	})
+	// ASSERT: The action should've failed due to invalid account address.
+	require.ErrorContains(t, err, "unable to decode account address")
+
+	// ARRANGE: Generate a user account.
+	user := utils.TestAccount()
+
+	// ACT: Attempt to burn from user with insufficient funds.
+	_, err = server.Burn(ctx, &types.MsgBurn{
+		Signer: burner.Address,
+		From:   user.Address,
+		Amount: ONE,
+	})
+	// ASSERT: The action should've failed due to insufficient funds.
+	require.ErrorContains(t, err, "unable to transfer from user to module")
+
+	// ARRANGE: Give user 1 $USDY.
+	bank.Balances[user.Address] = sdk.NewCoins(sdk.NewCoin(k.Denom, ONE))
+
+	// ACT: Attempt to burn.
+	_, err = server.Burn(ctx, &types.MsgBurn{
+		Signer: burner.Address,
+		From:   user.Address,
+		Amount: ONE,
+	})
+	// ASSERT: The action should've succeeded.
+	require.NoError(t, err)
+	require.True(t, bank.Balances[user.Address].IsZero())
+	require.True(t, bank.Balances[types.ModuleName].IsZero())
+}
+
+func TestMint(t *testing.T) {
+	bank := mocks.BankKeeper{
+		Balances: make(map[string]sdk.Coins),
+	}
+	k, ctx := mocks.AuraKeeperWithBank(t, bank)
+	server := keeper.NewMsgServer(k)
+
+	// ARRANGE: Set minter in state.
+	minter := utils.TestAccount()
+	require.NoError(t, k.Minters.Set(ctx, minter.Address))
+
+	// ACT: Attempt to mint with invalid signer.
+	_, err := server.Mint(ctx, &types.MsgMint{
+		Signer: utils.TestAccount().Address,
+	})
+	// ASSERT: The action should've failed due to invalid signer.
+	require.ErrorContains(t, err, types.ErrInvalidMinter.Error())
+
+	// ACT: Attempt to mint with invalid account address.
+	_, err = server.Mint(ctx, &types.MsgMint{
+		Signer: minter.Address,
+		To:     "cosmos10d07y265gmmuvt4z0w9aw880jnsr700j6zn9kn",
+	})
+	// ASSERT: The action should've failed due to invalid account address.
+	require.ErrorContains(t, err, "unable to decode account address")
+
+	// ARRANGE: Generate a user account.
+	user := utils.TestAccount()
+
+	// ACT: Attempt to mint.
+	_, err = server.Mint(ctx, &types.MsgMint{
+		Signer: minter.Address,
+		To:     user.Address,
+		Amount: ONE,
+	})
+	// ASSERT: The action should've succeeded.
+	require.NoError(t, err)
+	require.Equal(t, ONE, bank.Balances[user.Address].AmountOf(k.Denom))
+	require.True(t, bank.Balances[types.ModuleName].IsZero())
+}
+
 func TestPause(t *testing.T) {
 	k, ctx := mocks.AuraKeeper(t)
 	server := keeper.NewMsgServer(k)