[Code Health] Ensure application module msg responses are non-empty (#…

…974)

## Summary

Ensure all application module msg responses are non-empty. This adds a
`Application` field to the following protobuf type(s), and updates the
unit tests to assert for presence and correctness.

- `MsgUnstakeApplicationResponse`
- `MsgUndelegateFromGatewayResponse`

## Issue

- #663

## Type of change

Select one or more from the following:

- [ ] New feature, functionality or library
- [ ] Consensus breaking; add the `consensus-breaking` label if so. See
#791 for details
- [ ] Bug fix
- [x] Code health or cleanup
- [ ] Documentation
- [ ] Other (specify)

## Testing

- [ ] **Documentation**: `make docusaurus_start`; only needed if you
make doc changes
- [ ] **Unit Tests**: `make go_develop_and_test`
- [ ] **LocalNet E2E Tests**: `make test_e2e`
- [ ] **DevNet E2E Tests**: Add the `devnet-test-e2e` label to the PR.

## Sanity Checklist

- [x] I have tested my changes using the available tooling
- [ ] I have commented my code
- [x] I have performed a self-review of my own code; both comments &
source code
- [ ] I create and reference any new tickets, if applicable
- [ ] I have left TODOs throughout the codebase, if applicable

proto/poktroll/application/tx.proto

@@ -69,7 +69,9 @@ message MsgUnstakeApplication {
   string address = 1;
 }
 
-message MsgUnstakeApplicationResponse {}
+message MsgUnstakeApplicationResponse {
+  poktroll.application.Application application = 1;
+}
 
 message MsgDelegateToGateway {
   option (cosmos.msg.v1.signer) = "app_address"; // https://docs.cosmos.network/main/build/building-modules/messages-and-queries
@@ -87,7 +89,9 @@ message MsgUndelegateFromGateway {
   string gateway_address = 2 [(cosmos_proto.scalar) = "cosmos.AddressString"]; // The Bech32 address of the gateway the application wants to undelegate from.
 }
 
-message MsgUndelegateFromGatewayResponse {}
+message MsgUndelegateFromGatewayResponse {
+  poktroll.application.Application application = 1;
+}
 
 message MsgTransferApplication {
   option (cosmos.msg.v1.signer) = "source_address";

x/application/keeper/msg_server_delegate_to_gateway_test.go

@@ -37,10 +37,19 @@ func TestMsgServer_DelegateToGateway_SuccessfullyDelegate(t *testing.T) {
 		},
 	}
 
+	expectedApp := &apptypes.Application{
+		Address:                   stakeMsg.GetAddress(),
+		Stake:                     stakeMsg.GetStake(),
+		ServiceConfigs:            stakeMsg.GetServices(),
+		DelegateeGatewayAddresses: make([]string, 0),
+		PendingUndelegations:      make(map[uint64]apptypes.UndelegatingGatewayList),
+	}
+
 	// Stake the application & verify that the application exists
 	_, err := srv.StakeApplication(ctx, stakeMsg)
 	require.NoError(t, err)
-	_, isAppFound := k.GetApplication(ctx, appAddr)
+	foundApp, isAppFound := k.GetApplication(ctx, appAddr)
+	require.Equal(t, expectedApp, &foundApp)
 	require.True(t, isAppFound)
 
 	// Prepare the delegation message
@@ -49,21 +58,17 @@ func TestMsgServer_DelegateToGateway_SuccessfullyDelegate(t *testing.T) {
 		GatewayAddress: gatewayAddr1,
 	}
 
+	expectedApp.DelegateeGatewayAddresses = append(expectedApp.DelegateeGatewayAddresses, gatewayAddr1)
+
 	// Delegate the application to the gateway
-	_, err = srv.DelegateToGateway(ctx, delegateMsg)
+	delegateRes, err := srv.DelegateToGateway(ctx, delegateMsg)
 	require.NoError(t, err)
+	require.Equal(t, delegateRes.GetApplication(), expectedApp)
 
 	sdkCtx := sdk.UnwrapSDKContext(ctx)
 	currentHeight := sdkCtx.BlockHeight()
 	sharedParams := sharedtypes.DefaultParams()
 	sessionEndHeight := sharedtypes.GetSessionEndHeight(&sharedParams, currentHeight)
-	expectedApp := &apptypes.Application{
-		Address:                   stakeMsg.GetAddress(),
-		Stake:                     stakeMsg.GetStake(),
-		ServiceConfigs:            stakeMsg.GetServices(),
-		DelegateeGatewayAddresses: []string{gatewayAddr1},
-		PendingUndelegations:      make(map[uint64]apptypes.UndelegatingGatewayList),
-	}
 	expectedEvent := &apptypes.EventRedelegation{
 		Application:      expectedApp,
 		SessionEndHeight: sessionEndHeight,
@@ -77,11 +82,6 @@ func TestMsgServer_DelegateToGateway_SuccessfullyDelegate(t *testing.T) {
 	// Reset the events, as if a new block were created.
 	ctx, sdkCtx = testevents.ResetEventManager(ctx)
 
-	// Verify that the application exists
-	foundApp, isAppFound := k.GetApplication(ctx, appAddr)
-	require.True(t, isAppFound)
-	require.EqualValues(t, expectedApp, &foundApp)
-
 	// Prepare a second delegation message
 	delegateMsg2 := &apptypes.MsgDelegateToGateway{
 		AppAddress:     appAddr,

x/application/keeper/msg_server_stake_application_test.go

@@ -42,18 +42,22 @@ func TestMsgServer_StakeApplication_SuccessfulCreateAndUpdate(t *testing.T) {
 	require.NoError(t, err)
 
 	// Assert that the response contains the staked application.
-	app := stakeAppRes.GetApplication()
-	require.Equal(t, stakeMsg.GetAddress(), app.GetAddress())
-	require.Equal(t, stakeMsg.GetStake(), app.GetStake())
-	require.Equal(t, stakeMsg.GetServices(), app.GetServiceConfigs())
+	expectedApp := &apptypes.Application{
+		Address:                   stakeMsg.GetAddress(),
+		Stake:                     stakeMsg.GetStake(),
+		ServiceConfigs:            stakeMsg.GetServices(),
+		PendingUndelegations:      make(map[uint64]apptypes.UndelegatingGatewayList),
+		DelegateeGatewayAddresses: make([]string, 0),
+	}
+	require.Equal(t, expectedApp, stakeAppRes.GetApplication())
 
 	// Assert that the EventApplicationStaked event is emitted.
 	sharedParams := sharedtypes.DefaultParams()
 	currentHeight := cosmostypes.UnwrapSDKContext(ctx).BlockHeight()
 	sessionEndHeight := sharedtypes.GetSessionEndHeight(&sharedParams, currentHeight)
 	expectedEvent, err := cosmostypes.TypedEventToEvent(
 		&apptypes.EventApplicationStaked{
-			Application:      app,
+			Application:      stakeAppRes.GetApplication(),
 			SessionEndHeight: sessionEndHeight,
 		},
 	)
@@ -85,8 +89,19 @@ func TestMsgServer_StakeApplication_SuccessfulCreateAndUpdate(t *testing.T) {
 	}
 
 	// Update the staked application
-	_, err = srv.StakeApplication(ctx, updateStakeMsg)
+	stakeAppRes, err = srv.StakeApplication(ctx, updateStakeMsg)
 	require.NoError(t, err)
+
+	// Assert that the response contains the staked application.
+	expectedApp = &apptypes.Application{
+		Address:                   updateStakeMsg.GetAddress(),
+		Stake:                     updateStakeMsg.GetStake(),
+		ServiceConfigs:            updateStakeMsg.GetServices(),
+		PendingUndelegations:      make(map[uint64]apptypes.UndelegatingGatewayList),
+		DelegateeGatewayAddresses: make([]string, 0),
+	}
+	require.Equal(t, expectedApp, stakeAppRes.GetApplication())
+
 	foundApp, isAppFound = k.GetApplication(ctx, appAddr)
 	require.True(t, isAppFound)
 	require.Equal(t, &upStake, foundApp.Stake)

x/application/keeper/msg_server_undelegate_from_gateway.go

@@ -87,7 +87,9 @@ func (k msgServer) UndelegateFromGateway(ctx context.Context, msg *apptypes.MsgU
 	logger.Info(fmt.Sprintf("Emitted application redelegation event %v", event))
 
 	isSuccessful = true
-	return &apptypes.MsgUndelegateFromGatewayResponse{}, nil
+	return &apptypes.MsgUndelegateFromGatewayResponse{
+		Application: &foundApp,
+	}, nil
 }
 
 // recordPendingUndelegation adds the given gateway address to the application's

x/application/keeper/msg_server_undelegate_from_gateway_test.go

@@ -102,10 +102,6 @@ func TestMsgServer_UndelegateFromGateway_SuccessfullyUndelegate(t *testing.T) {
 		GatewayAddress: expectedGatewayAddresses[3],
 	}
 
-	// Undelegate the application from the gateway
-	_, err = srv.UndelegateFromGateway(ctx, undelegateMsg)
-	require.NoError(t, err)
-
 	// Assert that the EventRedelegation event is emitted.
 	expectedGatewayAddresses = append(expectedGatewayAddresses[:3], expectedGatewayAddresses[4:]...)
 	expectedApp := &apptypes.Application{
@@ -118,6 +114,11 @@ func TestMsgServer_UndelegateFromGateway_SuccessfullyUndelegate(t *testing.T) {
 		},
 	}
 
+	// Undelegate the application from the gateway
+	undelegateRes, err := srv.UndelegateFromGateway(ctx, undelegateMsg)
+	require.NoError(t, err)
+	require.Equal(t, undelegateRes.GetApplication(), expectedApp)
+
 	events = sdkCtx.EventManager().Events()
 	redelgationEvents = testevents.FilterEvents[*apptypes.EventRedelegation](t, events)
 	lastEventIdx := len(redelgationEvents) - 1

x/application/keeper/msg_server_unstake_application.go

@@ -94,5 +94,7 @@ func (k msgServer) UnstakeApplication(
 	}
 
 	isSuccessful = true
-	return &apptypes.MsgUnstakeApplicationResponse{}, nil
+	return &apptypes.MsgUnstakeApplicationResponse{
+		Application: &foundApp,
+	}, nil
 }

x/application/keeper/msg_server_unstake_application_test.go

@@ -146,12 +146,14 @@ func TestMsgServer_UnstakeApplication_CancelUnbondingIfRestaked(t *testing.T) {
 
 	// Initiate the application unstaking
 	unstakeMsg := &apptypes.MsgUnstakeApplication{Address: appAddr}
-	_, err = srv.UnstakeApplication(ctx, unstakeMsg)
+	unstakeRes, err := srv.UnstakeApplication(ctx, unstakeMsg)
 	require.NoError(t, err)
 
-	// Assert that the EventApplicationUnbondingBegin event is emitted.
 	foundApp.UnstakeSessionEndHeight = uint64(sessionEndHeight)
 	foundApp.DelegateeGatewayAddresses = make([]string, 0)
+	require.Equal(t, &foundApp, unstakeRes.GetApplication())
+
+	// Assert that the EventApplicationUnbondingBegin event is emitted.
 	unbondingEndHeight := apptypes.GetApplicationUnbondingHeight(&sharedParams, &foundApp)
 	expectedAppUnbondingBeginEvent := &apptypes.EventApplicationUnbondingBegin{
 		Application:        &foundApp,