refactor: remove unnecessary defers in tests (#4713)

Since Go 1.14 gomock will use `T.Cleanup` automatically.

This is the results of running:
```sh
find . -type f -name "*.go" -exec sed -i '' '/defer ctrl\.Finish()/d' {} +
find . -type f -name "*.go" -exec sed -i '' '/defer ctlr\.Finish()/d' {} +
find . -type f -name "*.go" -exec sed -i '' '/defer mctrl\.Finish()/d' {} +
find . -type f -name "*.go" -exec sed -i '' '/defer rootCtrl\.Finish()/d' {} +
```
And cleaning up unused variables by hand.

control/beacon/beacon_test.go

@@ -53,7 +53,6 @@ func TestBeaconDiversity(t *testing.T) {
 		},
 	}
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 
 	g := graph.NewDefaultGraph(mctrl)
 	bseg := testBeacon(g, tests[0].beacon...)

control/beacon/store_test.go

@@ -48,7 +48,6 @@ func testStoreSelection(t *testing.T,
 	methodToTest func(store *beacon.Store) ([]beacon.Beacon, error)) {
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 	g := graph.NewDefaultGraph(mctrl)
 
 	// Ensure remote out if is set in last AS entry.
@@ -111,7 +110,6 @@ func testStoreSelection(t *testing.T,
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 			db := mock_beacon.NewMockDB(mctrl)
 			policies := beacon.Policies{
 				Prop:    beacon.Policy{BestSetSize: test.bestSize},
@@ -158,7 +156,6 @@ func testCoreStoreSelection(t *testing.T,
 	methodToTest func(store *beacon.CoreStore) ([]beacon.Beacon, error)) {
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 	g := graph.NewDefaultGraph(mctrl)
 
 	// Ensure remote out if is set in last AS entry.
@@ -228,7 +225,6 @@ func testCoreStoreSelection(t *testing.T,
 	for _, test := range tests {
 		t.Run(test.name, func(t *testing.T) {
 			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 			db := mock_beacon.NewMockDB(mctrl)
 			policies := beacon.CorePolicies{
 				Prop:    beacon.Policy{BestSetSize: test.bestSize},

control/beaconing/extender_test.go

@@ -25,7 +25,6 @@ import (
 	"testing"
 	"time"
 
-	"github.com/golang/mock/gomock"
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
@@ -91,8 +90,6 @@ func TestDefaultExtenderExtend(t *testing.T) {
 	}
 	for name, tc := range testsCases {
 		t.Run(name, func(t *testing.T) {
-			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 			// Setup interfaces with active parent, child and one peer interface.
 			intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 			for _, peer := range tc.peers {
@@ -167,8 +164,6 @@ func TestDefaultExtenderExtend(t *testing.T) {
 		})
 	}
 	t.Run("the maximum expiration time is respected", func(t *testing.T) {
-		mctrl := gomock.NewController(t)
-		defer mctrl.Finish()
 		intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 		require.NoError(t, err)
 		ext := &beaconing.DefaultExtender{
@@ -261,8 +256,6 @@ func TestDefaultExtenderExtend(t *testing.T) {
 		}
 		for name, tc := range testCases {
 			t.Run(name, func(t *testing.T) {
-				mctrl := gomock.NewController(t)
-				defer mctrl.Finish()
 				intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 				require.NoError(t, err)
 				ext := &beaconing.DefaultExtender{
@@ -332,8 +325,6 @@ func TestDefaultExtenderExtend(t *testing.T) {
 		}
 		for name, tc := range testCases {
 			t.Run(name, func(t *testing.T) {
-				mctrl := gomock.NewController(t)
-				defer mctrl.Finish()
 				intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 				ext := &beaconing.DefaultExtender{
 					IA: topo.IA(),

control/beaconing/handler_test.go

@@ -47,7 +47,6 @@ func TestHandlerHandleBeacon(t *testing.T) {
 
 	validBeacon := func() beacon.Beacon {
 		mctrl := gomock.NewController(t)
-		defer mctrl.Finish()
 		g := graph.NewDefaultGraph(mctrl)
 		return beacon.Beacon{
 			Segment: testSegment(g, []uint16{graph.If_220_X_120_B, graph.If_120_A_110_X}),
@@ -257,7 +256,6 @@ func TestHandlerHandleBeacon(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 
 			handler := beaconing.Handler{
 				LocalIA:    localIA,

control/beaconing/originator_test.go

@@ -63,7 +63,6 @@ func TestOriginatorRun(t *testing.T) {
 	}
 	t.Run("run originates ifID packets on all active interfaces", func(t *testing.T) {
 		mctrl := gomock.NewController(t)
-		defer mctrl.Finish()
 		intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 		senderFactory := mock_beaconing.NewMockSenderFactory(mctrl)
 		o := beaconing.Originator{
@@ -126,7 +125,6 @@ func TestOriginatorRun(t *testing.T) {
 	})
 	t.Run("Fast recovery", func(t *testing.T) {
 		mctrl := gomock.NewController(t)
-		defer mctrl.Finish()
 		intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
 		senderFactory := mock_beaconing.NewMockSenderFactory(mctrl)
 		sender := mock_beaconing.NewMockSender(mctrl)

control/beaconing/propagator_test.go

@@ -52,7 +52,6 @@ func TestPropagatorRunNonCore(t *testing.T) {
 	}
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 	topo, err := topology.FromJSONFile(topoNonCore)
 	require.NoError(t, err)
 	intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
@@ -126,7 +125,6 @@ func TestPropagatorRunCore(t *testing.T) {
 	}
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 	topo, err := topology.FromJSONFile(topoCore)
 	require.NoError(t, err)
 	intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
@@ -212,7 +210,6 @@ func TestPropagatorFastRecovery(t *testing.T) {
 		{graph.If_130_B_120_A, graph.If_120_A_110_X},
 	}
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 	topo, err := topology.FromJSONFile(topoCore)
 	require.NoError(t, err)
 	intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})

control/beaconing/writer_test.go

@@ -87,7 +87,6 @@ func TestRegistrarRun(t *testing.T) {
 	for _, test := range testsLocal {
 		t.Run(test.name, func(t *testing.T) {
 			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 			topo, err := topology.FromJSONFile(test.fn)
 			require.NoError(t, err)
 			intfs := ifstate.NewInterfaces(interfaceInfos(topo), ifstate.Config{})
@@ -173,7 +172,6 @@ func TestRegistrarRun(t *testing.T) {
 	for _, test := range testsRemote {
 		t.Run(test.name, func(t *testing.T) {
 			mctrl := gomock.NewController(t)
-			defer mctrl.Finish()
 
 			topo, err := topology.FromJSONFile(test.fn)
 			require.NoError(t, err)
@@ -275,7 +273,6 @@ func TestRegistrarRun(t *testing.T) {
 
 	t.Run("Faulty beacons are not sent", func(t *testing.T) {
 		mctrl := gomock.NewController(t)
-		defer mctrl.Finish()
 
 		topo, err := topology.FromJSONFile(topoNonCore)
 		require.NoError(t, err)

control/drkey/grpc/drkey_service_test.go

@@ -52,7 +52,6 @@ func TestDRKeySV(t *testing.T) {
 	sv, targetResp := getSVandResp(t)
 
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	serviceStore := mock_grpc.NewMockEngine(ctrl)
 	serviceStore.EXPECT().GetSecretValue(gomock.Any(), gomock.Any()).Return(sv, nil)
@@ -305,7 +304,6 @@ func TestLevel1(t *testing.T) {
 
 func TestASHost(t *testing.T) {
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	engine := mock_grpc.NewMockEngine(ctrl)
 	engine.EXPECT().DeriveASHost(gomock.Any(), gomock.Any()).Return(
@@ -336,7 +334,6 @@ func TestASHost(t *testing.T) {
 
 func TestHostAS(t *testing.T) {
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	engine := mock_grpc.NewMockEngine(ctrl)
 	engine.EXPECT().DeriveHostAS(gomock.Any(), gomock.Any()).Return(
@@ -367,7 +364,6 @@ func TestHostAS(t *testing.T) {
 
 func TestHostHost(t *testing.T) {
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	engine := mock_grpc.NewMockEngine(ctrl)
 	engine.EXPECT().DeriveHostHost(gomock.Any(), gomock.Any()).Return(

control/drkey/grpc/fetcher_test.go

@@ -60,7 +60,6 @@ func TestLevel1KeyFetching(t *testing.T) {
 	require.NoError(t, err)
 
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	lvl1db := mock_grpc.NewMockEngine(ctrl)
 	lvl1db.EXPECT().DeriveLevel1(gomock.Any()).AnyTimes().Return(drkey.Level1Key{}, nil)

control/drkey/prefetcher_test.go

@@ -33,7 +33,6 @@ var _ periodic.Task = (*cs_drkey.Prefetcher)(nil)
 
 func TestPrefetcherRun(t *testing.T) {
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 
 	mock_engine := mock_drkey.NewMockLevel1Engine(mctrl)
 

control/drkey/service_engine_test.go

@@ -104,7 +104,6 @@ func TestDeriveHostAS(t *testing.T) {
 	defer lvl1db.Close()
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 
 	fetcher := mock_drkey.NewMockFetcher(mctrl)
 	fetcher.EXPECT().Level1(gomock.Any(), gomock.Any()).DoAndReturn(
@@ -182,7 +181,6 @@ func TestGetLevel1Key(t *testing.T) {
 	copy(secondLevel1Key.Key[:], k)
 
 	mctrl := gomock.NewController(t)
-	defer mctrl.Finish()
 
 	fetcher := mock_drkey.NewMockFetcher(mctrl)
 	gomock.InOrder(

control/mgmtapi/api_test.go

@@ -885,7 +885,6 @@ func TestAPI(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 
 			req, err := http.NewRequest("GET", tc.RequestURL, nil)
 			require.NoError(t, err)

control/segreq/authoritative_test.go

@@ -120,7 +120,6 @@ func TestAuthoritativeClassify(t *testing.T) {
 	for name, test := range tests {
 		t.Run(name, func(t *testing.T) {
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 
 			p := AuthoritativeLookup{
 				LocalIA:     test.LocalIA,

control/segreq/forwarder_test.go

@@ -213,7 +213,6 @@ func TestForwarderClassify(t *testing.T) {
 	for name, test := range tests {
 		t.Run(name, func(t *testing.T) {
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 
 			f := ForwardingLookup{LocalIA: test.LocalIA, CoreChecker: newMockCoreChecker(ctrl)}
 			segType, err := f.classify(context.Background(), test.Request.Src, test.Request.Dst)

control/segreq/helpers_test.go

@@ -72,7 +72,6 @@ func TestCoreChecker(t *testing.T) {
 	for name, test := range tests {
 		t.Run(name, func(t *testing.T) {
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 			i := mock_trust.NewMockInspector(ctrl)
 			test.PrepareInspector(i)
 			c := segreq.CoreChecker{Inspector: i}

control/trust/crypto_loader_test.go

@@ -75,7 +75,6 @@ func TestChainLoaderChains(t *testing.T) {
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 
 			dir, db := tc.prepare(t, ctrl)
 			loader := cstrust.CryptoLoader{

daemon/drkey/grpc/fetching_test.go

@@ -35,7 +35,6 @@ var _ sd_drkey.Fetcher = (*sd_grpc.Fetcher)(nil)
 
 func TestGetHostHost(t *testing.T) {
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	now := time.Now().UTC()
 	epochBegin := timestamppb.New(now)

gateway/control/engine_test.go

@@ -32,7 +32,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("double run", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			SessionConfigs:          nil,
@@ -55,7 +54,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("nil routing table", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			PathMonitor:             mock_control.NewMockPathMonitor(ctrl),
@@ -69,7 +67,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("nil path monitor", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			SessionConfigs:          nil,
@@ -84,7 +81,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("nil probe conn factory", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			SessionConfigs:          nil,
@@ -99,7 +95,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("nil dataplane session factory", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			SessionConfigs:   nil,
@@ -114,7 +109,6 @@ func TestEngineRun(t *testing.T) {
 	t.Run("close before run", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		engine := &control.Engine{
 			SessionConfigs:          nil,

gateway/control/enginecontroller_test.go

@@ -35,7 +35,6 @@ func TestEngineControllerRun(t *testing.T) {
 	t.Run("double run", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		configurationUpdates := make(chan []*control.SessionConfig)
 		routingTableSwapper := mock_control.NewMockRoutingTableSwapper(ctrl)
@@ -63,7 +62,6 @@ func TestEngineControllerRun(t *testing.T) {
 	t.Run("nil configuration updates", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		routingTableSwapper := mock_control.NewMockRoutingTableSwapper(ctrl)
 		routingTableFactory := mock_control.NewMockRoutingTableFactory(ctrl)
@@ -82,7 +80,6 @@ func TestEngineControllerRun(t *testing.T) {
 	t.Run("nil routing table swapper", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		configurationUpdates := make(chan []*control.SessionConfig)
 		routingTableFactory := mock_control.NewMockRoutingTableFactory(ctrl)
@@ -101,7 +98,6 @@ func TestEngineControllerRun(t *testing.T) {
 	t.Run("nil routing table factory", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		configurationUpdates := make(chan []*control.SessionConfig)
 		routingTableSwapper := mock_control.NewMockRoutingTableSwapper(ctrl)
@@ -120,7 +116,6 @@ func TestEngineControllerRun(t *testing.T) {
 	t.Run("nil engine factory", func(t *testing.T) {
 		t.Parallel()
 		ctrl := gomock.NewController(t)
-		defer ctrl.Finish()
 
 		configurationUpdates := make(chan []*control.SessionConfig)
 		routingTableSwapper := mock_control.NewMockRoutingTableSwapper(ctrl)

gateway/control/grpc/prefix_server_test.go

@@ -98,7 +98,6 @@ func TestIPPrefixServerPrefixes(t *testing.T) {
 	for name, tc := range testCases {
 		t.Run(name, func(t *testing.T) {
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 			s := grpc.IPPrefixServer{
 				LocalIA:    local,
 				Advertiser: tc.Advertiser(t, ctrl),

gateway/control/grpc/probeserver_test.go

@@ -35,7 +35,6 @@ import (
 
 func TestControlDispatcher(t *testing.T) {
 	ctrl := gomock.NewController(t)
-	defer ctrl.Finish()
 
 	src := &snet.UDPAddr{IA: addr.MustParseIA("1-ff00:0:110")}
 

gateway/control/prefixesfilter_test.go

@@ -171,7 +171,6 @@ accept    1-ff00:0:113    1-ff00:0:110    10.3.0.0/25`))
 		t.Run(name, func(t *testing.T) {
 			t.Parallel()
 			ctrl := gomock.NewController(t)
-			defer ctrl.Finish()
 
 			f := tc.CreateFilter(t, ctrl)
 			for _, input := range tc.Inputs {