From 28882810c1941e853c255c57843015a501c85583 Mon Sep 17 00:00:00 2001
From: Kevin Yang <5478483+k-yang@users.noreply.github.com>
Date: Wed, 20 Mar 2024 16:09:51 +0900
Subject: [PATCH] test(inflation): add additional burn test cases (#1828)

* test(inflation): add negative burn tests

* test(inflation): add total supply check to burn tests
---
 x/inflation/keeper/keeper_test.go     | 24 +++++++++++++++++++++---
 x/inflation/keeper/msg_server_test.go | 23 +++++++++++++++++++++++
 2 files changed, 44 insertions(+), 3 deletions(-)

diff --git a/x/inflation/keeper/keeper_test.go b/x/inflation/keeper/keeper_test.go
index 4100e13c8..391efe14f 100644
--- a/x/inflation/keeper/keeper_test.go
+++ b/x/inflation/keeper/keeper_test.go
@@ -20,33 +20,51 @@ func TestBurn(t *testing.T) {
 	testCases := []struct {
 		name        string
 		sender      sdk.AccAddress
+		mintCoin    sdk.Coin
 		burnCoin    sdk.Coin
 		expectedErr error
 	}{
 		{
 			name:        "pass",
 			sender:      testutil.AccAddress(),
-			burnCoin:    sdk.NewCoin("nibiru", sdk.NewInt(100)),
+			mintCoin:    sdk.NewCoin("unibi", sdk.NewInt(100)),
+			burnCoin:    sdk.NewCoin("unibi", sdk.NewInt(100)),
 			expectedErr: nil,
 		},
+		{
+			name:        "not enough coins",
+			sender:      testutil.AccAddress(),
+			mintCoin:    sdk.NewCoin("unibi", sdk.NewInt(100)),
+			burnCoin:    sdk.NewCoin("unibi", sdk.NewInt(101)),
+			expectedErr: fmt.Errorf("spendable balance 100unibi is smaller than 101unibi: insufficient funds"),
+		},
 	}
+
 	for _, tc := range testCases {
 		t.Run(fmt.Sprintf("Case %s", tc.name), func(t *testing.T) {
 			nibiruApp, ctx := testapp.NewNibiruTestAppAndContext()
+
+			// mint and send money to the sender
 			require.NoError(t,
 				nibiruApp.BankKeeper.MintCoins(
-					ctx, types.ModuleName, sdk.NewCoins(tc.burnCoin)))
+					ctx, types.ModuleName, sdk.NewCoins(tc.mintCoin)))
 			require.NoError(t,
 				nibiruApp.BankKeeper.SendCoinsFromModuleToAccount(
-					ctx, types.ModuleName, tc.sender, sdk.NewCoins(tc.burnCoin)),
+					ctx, types.ModuleName, tc.sender, sdk.NewCoins(tc.mintCoin)),
 			)
 
+			supply := nibiruApp.BankKeeper.GetSupply(ctx, "unibi")
+			require.Equal(t, tc.mintCoin.Amount, supply.Amount)
+
 			// Burn coins
 			err := nibiruApp.InflationKeeper.Burn(ctx, sdk.NewCoins(tc.burnCoin), tc.sender)
+			supply = nibiruApp.BankKeeper.GetSupply(ctx, "unibi")
 			if tc.expectedErr != nil {
 				require.EqualError(t, err, tc.expectedErr.Error())
+				require.Equal(t, tc.mintCoin.Amount, supply.Amount)
 			} else {
 				require.NoError(t, err)
+				require.Equal(t, sdk.ZeroInt(), supply.Amount)
 			}
 		})
 	}
diff --git a/x/inflation/keeper/msg_server_test.go b/x/inflation/keeper/msg_server_test.go
index 49cfa1620..cc37a97a3 100644
--- a/x/inflation/keeper/msg_server_test.go
+++ b/x/inflation/keeper/msg_server_test.go
@@ -88,4 +88,27 @@ func TestMsgBurn(t *testing.T) {
 
 	_, err = msgServer.Burn(ctx, &msg)
 	require.NoError(t, err)
+	supply := app.BankKeeper.GetSupply(ctx, "unibi")
+	require.Equal(t, sdk.ZeroInt(), supply.Amount)
+}
+
+func TestMsgBurn_NotEnoughCoins(t *testing.T) {
+	app, ctx := testapp.NewNibiruTestAppAndContext()
+	sender := testutil.AccAddress()
+	err := app.BankKeeper.MintCoins(ctx, types.ModuleName, sdk.NewCoins(sdk.NewCoin("unibi", sdk.NewInt(100))))
+	require.NoError(t, err)
+	err = app.BankKeeper.SendCoinsFromModuleToAccount(ctx, types.ModuleName, sender, sdk.NewCoins(sdk.NewCoin("unibi", sdk.NewInt(100))))
+	require.NoError(t, err)
+
+	msgServer := keeper.NewMsgServerImpl(app.InflationKeeper)
+
+	msg := types.MsgBurn{
+		Sender: sender.String(),
+		Coin:   sdk.NewCoin("unibi", sdk.NewInt(101)),
+	}
+
+	_, err = msgServer.Burn(ctx, &msg)
+	require.EqualError(t, err, "spendable balance 100unibi is smaller than 101unibi: insufficient funds")
+	supply := app.BankKeeper.GetSupply(ctx, "unibi")
+	require.Equal(t, sdk.NewInt(100), supply.Amount)
 }