*: fix staticcheck errors

Fix following errors from staticcheck:
- remove redundant return statements
- use for range instead of for select
- use time.Since instead of time.Now().Sub
- omit comparison to bool constant
- replace T.Fatal and T.Fatalf in tests with T.Error and T.Fatalf respectively because the goroutine calls T.Fatal must be called in the same goroutine as the test
- fix error strings that should not be capitalized
- use sort.Strings(...) instead of sort.Sort(sort.StringSlice(...))
- use he status code of Canceled instead of grpc.ErrClientConnClosing which is deprecated
- use use status.Errorf instead of grpc.Errorf which is deprecated

auth/store_test.go

@@ -751,10 +751,10 @@ func TestHammerSimpleAuthenticate(t *testing.T) {
 				token := fmt.Sprintf("%s(%d)", user, i)
 				ctx := context.WithValue(context.WithValue(context.TODO(), AuthenticateParamIndex{}, uint64(1)), AuthenticateParamSimpleTokenPrefix{}, token)
 				if _, err := as.Authenticate(ctx, user, "123"); err != nil {
-					t.Fatal(err)
+					t.Error(err)
 				}
 				if _, err := as.AuthInfoFromCtx(ctx); err != nil {
-					t.Fatal(err)
+					t.Error(err)
 				}
 			}(u)
 		}

client/client.go

@@ -640,11 +640,11 @@ func (r *redirectFollowingHTTPClient) Do(ctx context.Context, act httpAction) (*
 		if resp.StatusCode/100 == 3 {
 			hdr := resp.Header.Get("Location")
 			if hdr == "" {
-				return nil, nil, fmt.Errorf("Location header not set")
+				return nil, nil, fmt.Errorf("location header not set")
 			}
 			loc, err := url.Parse(hdr)
 			if err != nil {
-				return nil, nil, fmt.Errorf("Location header not valid URL: %s", hdr)
+				return nil, nil, fmt.Errorf("location header not valid URL: %s", hdr)
 			}
 			next = &redirectedHTTPAction{
 				action:   act,

client/client_test.go

@@ -691,7 +691,7 @@ func TestRedirectFollowingHTTPClient(t *testing.T) {
 					},
 				},
 			},
-			wantErr: errors.New("Location header not set"),
+			wantErr: errors.New("location header not set"),
 		},
 
 		// fail if Location header is invalid
@@ -707,7 +707,7 @@ func TestRedirectFollowingHTTPClient(t *testing.T) {
 					},
 				},
 			},
-			wantErr: errors.New("Location header not valid URL: :"),
+			wantErr: errors.New("location header not valid URL: :"),
 		},
 
 		// fail if redirects checked way too many times
@@ -795,7 +795,7 @@ func TestHTTPClusterClientSync(t *testing.T) {
 
 	want = []string{"http://127.0.0.1:2379", "http://127.0.0.1:4001", "http://127.0.0.1:4002", "http://127.0.0.1:4003"}
 	got = hc.Endpoints()
-	sort.Sort(sort.StringSlice(got))
+	sort.Strings(got)
 	if !reflect.DeepEqual(want, got) {
 		t.Fatalf("incorrect endpoints post-Sync: want=%#v got=%#v", want, got)
 	}

client/keys.go

@@ -66,7 +66,7 @@ func (e Error) Error() string {
 }
 
 var (
-	ErrInvalidJSON = errors.New("client: response is invalid json. The endpoint is probably not valid etcd cluster endpoint.")
+	ErrInvalidJSON = errors.New("client: response is invalid json. The endpoint is probably not valid etcd cluster endpoint")
 	ErrEmptyBody   = errors.New("client: response body is empty")
 )
 

clientv3/balancer/balancer.go

@@ -224,7 +224,6 @@ func (bb *baseBalancer) HandleSubConnStateChange(sc balancer.SubConn, s connecti
 	}
 
 	bb.currentConn.UpdateBalancerState(bb.currentState, bb.Picker)
-	return
 }
 
 func (bb *baseBalancer) regeneratePicker() {

clientv3/balancer/grpc1.7-health.go

@@ -507,7 +507,7 @@ func (b *GRPC17Health) Get(ctx context.Context, opts grpc.BalancerGetOptions) (g
 		addr = b.pinAddr
 		b.mu.RUnlock()
 		if closed {
-			return grpc.Address{Addr: ""}, nil, grpc.ErrClientConnClosing
+			return grpc.Address{Addr: ""}, nil, context.Canceled
 		}
 		if addr == "" {
 			return grpc.Address{Addr: ""}, nil, ErrNoAddrAvilable
@@ -522,7 +522,7 @@ func (b *GRPC17Health) Get(ctx context.Context, opts grpc.BalancerGetOptions) (g
 		select {
 		case <-ch:
 		case <-b.donec:
-			return grpc.Address{Addr: ""}, nil, grpc.ErrClientConnClosing
+			return grpc.Address{Addr: ""}, nil, context.Canceled
 		case <-ctx.Done():
 			return grpc.Address{Addr: ""}, nil, ctx.Err()
 		}
@@ -532,7 +532,7 @@ func (b *GRPC17Health) Get(ctx context.Context, opts grpc.BalancerGetOptions) (g
 		b.mu.RUnlock()
 		// Close() which sets b.closed = true can be called before Get(), Get() must exit if balancer is closed.
 		if closed {
-			return grpc.Address{Addr: ""}, nil, grpc.ErrClientConnClosing
+			return grpc.Address{Addr: ""}, nil, context.Canceled
 		}
 		if addr != "" {
 			break

clientv3/balancer/grpc1.7-health_test.go

@@ -281,7 +281,7 @@ func (kcl *killConnListener) listen(l net.Listener) {
 			default:
 			}
 			if err != nil {
-				kcl.t.Fatal(err)
+				kcl.t.Error(err)
 			}
 			time.Sleep(1 * time.Millisecond)
 			conn.Close()

clientv3/client.go

@@ -627,7 +627,9 @@ func toErr(ctx context.Context, err error) error {
 			}
 		case codes.Unavailable:
 		case codes.FailedPrecondition:
-			err = grpc.ErrClientConnClosing
+			if ctx.Err() != nil {
+				err = ctx.Err()
+			}
 		}
 	}
 	return err

clientv3/concurrency/election_test.go

@@ -67,19 +67,13 @@ func TestResumeElection(t *testing.T) {
 	go func() {
 		o := e.Observe(ctx)
 		respChan <- nil
-		for {
-			select {
-			case resp, ok := <-o:
-				if !ok {
-					t.Fatal("Observe() channel closed prematurely")
-				}
-				// Ignore any observations that candidate1 was elected
-				if string(resp.Kvs[0].Value) == "candidate1" {
-					continue
-				}
-				respChan <- &resp
-				return
+		for resp := range o {
+			// Ignore any observations that candidate1 was elected
+			if string(resp.Kvs[0].Value) == "candidate1" {
+				continue
 			}
+			respChan <- &resp
+			return
 		}
 	}()
 

clientv3/doc.go

@@ -90,7 +90,7 @@
 //		// with etcd clientv3 <= v3.3
 //		if err == context.Canceled {
 //			// grpc balancer calls 'Get' with an inflight client.Close
-//		} else if err == grpc.ErrClientConnClosing {
+//		} else if err == codes.Canceled {
 //			// grpc balancer calls 'Get' after client.Close.
 //		}
 //		// with etcd clientv3 >= v3.4

clientv3/integration/kv_test.go

@@ -29,8 +29,8 @@ import (
 	"go.etcd.io/etcd/mvcc/mvccpb"
 	"go.etcd.io/etcd/pkg/testutil"
 
-	"google.golang.org/grpc"
 	"google.golang.org/grpc/codes"
+	"google.golang.org/grpc/status"
 )
 
 func TestKVPutError(t *testing.T) {
@@ -448,7 +448,7 @@ func TestKVGetErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v or %v, got %v", context.Canceled, codes.Canceled, err)
 		}
 	}()
 
@@ -475,7 +475,7 @@ func TestKVNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Get(context.TODO(), "foo")
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v or %v, got %v", context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v or %v, got %v", context.Canceled, codes.Canceled, err)
 		}
 		close(donec)
 	}()
@@ -689,7 +689,7 @@ func TestKVGetRetry(t *testing.T) {
 		// Get will fail, but reconnect will trigger
 		gresp, gerr := kv.Get(ctx, "foo")
 		if gerr != nil {
-			t.Fatal(gerr)
+			t.Error(gerr)
 		}
 		wkvs := []*mvccpb.KeyValue{
 			{
@@ -701,7 +701,7 @@ func TestKVGetRetry(t *testing.T) {
 			},
 		}
 		if !reflect.DeepEqual(gresp.Kvs, wkvs) {
-			t.Fatalf("bad get: got %v, want %v", gresp.Kvs, wkvs)
+			t.Errorf("bad get: got %v, want %v", gresp.Kvs, wkvs)
 		}
 		donec <- struct{}{}
 	}()
@@ -739,10 +739,10 @@ func TestKVPutFailGetRetry(t *testing.T) {
 		// Get will fail, but reconnect will trigger
 		gresp, gerr := kv.Get(context.TODO(), "foo")
 		if gerr != nil {
-			t.Fatal(gerr)
+			t.Error(gerr)
 		}
 		if len(gresp.Kvs) != 0 {
-			t.Fatalf("bad get kvs: got %+v, want empty", gresp.Kvs)
+			t.Errorf("bad get kvs: got %+v, want empty", gresp.Kvs)
 		}
 		donec <- struct{}{}
 	}()
@@ -908,7 +908,7 @@ func TestKVLargeRequests(t *testing.T) {
 			maxCallSendBytesClient: 10 * 1024 * 1024,
 			maxCallRecvBytesClient: 0,
 			valueSize:              10 * 1024 * 1024,
-			expectError:            grpc.Errorf(codes.ResourceExhausted, "trying to send message larger than max "),
+			expectError:            status.Errorf(codes.ResourceExhausted, "trying to send message larger than max "),
 		},
 		{
 			maxRequestBytesServer:  10 * 1024 * 1024,
@@ -922,7 +922,7 @@ func TestKVLargeRequests(t *testing.T) {
 			maxCallSendBytesClient: 10 * 1024 * 1024,
 			maxCallRecvBytesClient: 0,
 			valueSize:              10*1024*1024 + 5,
-			expectError:            grpc.Errorf(codes.ResourceExhausted, "trying to send message larger than max "),
+			expectError:            status.Errorf(codes.ResourceExhausted, "trying to send message larger than max "),
 		},
 	}
 	for i, test := range tests {

clientv3/integration/lease_test.go

@@ -28,7 +28,7 @@ import (
 	"go.etcd.io/etcd/integration"
 	"go.etcd.io/etcd/pkg/testutil"
 
-	"google.golang.org/grpc"
+	"google.golang.org/grpc/codes"
 )
 
 func TestLeaseNotFoundError(t *testing.T) {
@@ -300,9 +300,9 @@ func TestLeaseGrantErrConnClosed(t *testing.T) {
 		defer close(donec)
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			// grpc.ErrClientConnClosing if grpc-go balancer calls 'Get' after client.Close.
+			// codes.Canceled if grpc-go balancer calls 'Get' after client.Close.
 			// context.Canceled if grpc-go balancer calls 'Get' with an inflight client.Close.
-			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, codes.Canceled, err)
 		}
 	}()
 
@@ -372,7 +372,7 @@ func TestLeaseGrantNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Grant(context.TODO(), 5)
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Errorf("expected %v, %v or server unavailable, got %v", err != context.Canceled, codes.Canceled, err)
 		}
 		close(donec)
 	}()
@@ -405,7 +405,7 @@ func TestLeaseRevokeNewAfterClose(t *testing.T) {
 	go func() {
 		_, err := cli.Revoke(context.TODO(), leaseID)
 		if !clientv3.IsConnCanceled(err) {
-			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, grpc.ErrClientConnClosing, err)
+			t.Fatalf("expected %v, %v or server unavailable, got %v", err != context.Canceled, codes.Canceled, err)
 		}
 		close(donec)
 	}()
@@ -767,7 +767,7 @@ func TestV3LeaseFailureOverlap(t *testing.T) {
 				if err == nil || err == rpctypes.ErrTimeoutDueToConnectionLost {
 					return
 				}
-				t.Fatal(err)
+				t.Error(err)
 			}()
 		}
 	}

clientv3/integration/leasing_test.go

@@ -114,7 +114,7 @@ func TestLeasingInterval(t *testing.T) {
 	}
 
 	// load into cache
-	if resp, err = lkv.Get(context.TODO(), "abc/a"); err != nil {
+	if _, err = lkv.Get(context.TODO(), "abc/a"); err != nil {
 		t.Fatal(err)
 	}
 
@@ -389,7 +389,7 @@ func TestLeasingConcurrentPut(t *testing.T) {
 		go func() {
 			resp, perr := lkv.Put(context.TODO(), "k", "abc")
 			if perr != nil {
-				t.Fatal(perr)
+				t.Error(perr)
 			}
 			putc <- resp
 		}()
@@ -559,7 +559,7 @@ func TestLeasingOwnerPutResponse(t *testing.T) {
 	if _, err = clus.Client(0).Put(context.TODO(), "k", "abc"); err != nil {
 		t.Fatal(err)
 	}
-	gresp, gerr := lkv.Get(context.TODO(), "k")
+	_, gerr := lkv.Get(context.TODO(), "k")
 	if gerr != nil {
 		t.Fatal(gerr)
 	}
@@ -573,7 +573,7 @@ func TestLeasingOwnerPutResponse(t *testing.T) {
 
 	clus.Members[0].Stop(t)
 
-	gresp, gerr = lkv.Get(context.TODO(), "k")
+	gresp, gerr := lkv.Get(context.TODO(), "k")
 	if gerr != nil {
 		t.Fatal(gerr)
 	}
@@ -992,7 +992,7 @@ func TestLeasingTxnRandIfThenOrElse(t *testing.T) {
 		for i := 0; i < keyCount/2; i++ {
 			k := fmt.Sprintf("k-%d", rand.Intn(keyCount))
 			if _, err := kv.Get(context.TODO(), k); err != nil {
-				t.Fatal(err)
+				t.Error(err)
 			}
 			getc <- struct{}{}
 		}
@@ -1399,10 +1399,10 @@ func TestLeasingReconnectOwnerRevoke(t *testing.T) {
 		// blocks until lkv1 connection comes back
 		resp, err := lkv1.Get(cctx, "k")
 		if err != nil {
-			t.Fatal(err)
+			t.Error(err)
 		}
 		if string(resp.Kvs[0].Value) != "v" {
-			t.Fatalf(`expected "v" value, got %+v`, resp)
+			t.Errorf(`expected "v" value, got %+v`, resp)
 		}
 	}()
 	select {
@@ -1440,11 +1440,11 @@ func TestLeasingReconnectOwnerRevokeCompact(t *testing.T) {
 	clus.WaitLeader(t)
 
 	// put some more revisions for compaction
-	presp, err := clus.Client(1).Put(context.TODO(), "a", "123")
+	_, err := clus.Client(1).Put(context.TODO(), "a", "123")
 	if err != nil {
 		t.Fatal(err)
 	}
-	presp, err = clus.Client(1).Put(context.TODO(), "a", "123")
+	presp, err := clus.Client(1).Put(context.TODO(), "a", "123")
 	if err != nil {
 		t.Fatal(err)
 	}
@@ -1595,7 +1595,7 @@ func TestLeasingTxnAtomicCache(t *testing.T) {
 			}
 			tresp, err := lkv.Txn(context.TODO()).Then(gets...).Commit()
 			if err != nil {
-				t.Fatal(err)
+				t.Error(err)
 			}
 			revs := make([]int64, len(gets))
 			for i, resp := range tresp.Responses {
@@ -1604,7 +1604,7 @@ func TestLeasingTxnAtomicCache(t *testing.T) {
 			}
 			for i := 1; i < len(revs); i++ {
 				if revs[i] != revs[i-1] {
-					t.Fatalf("expected matching revisions, got %+v", revs)
+					t.Errorf("expected matching revisions, got %+v", revs)
 				}
 			}
 		}

clientv3/integration/metrics_test.go

@@ -54,12 +54,12 @@ func TestV3ClientMetrics(t *testing.T) {
 
 		ln, err = transport.NewUnixListener(addr)
 		if err != nil {
-			t.Fatalf("Error: %v occurred while listening on addr: %v", err, addr)
+			t.Errorf("Error: %v occurred while listening on addr: %v", err, addr)
 		}
 
 		err = srv.Serve(ln)
 		if err != nil && !transport.IsClosedConnError(err) {
-			t.Fatalf("Err serving http requests: %v", err)
+			t.Errorf("Err serving http requests: %v", err)
 		}
 	}()
 

clientv3/integration/mirror_test.go

@@ -90,7 +90,7 @@ func TestMirrorSyncBase(t *testing.T) {
 
 			for key := range keyCh {
 				if _, err := cli.Put(ctx, key, "test"); err != nil {
-					t.Fatal(err)
+					t.Error(err)
 				}
 			}
 		}()