code health: fix all places highlighted by linter

Changed error's suppression in check.yaml. The suppression of rule
`errcheck` may be removed after fixing errors check in all methods
with calling encodeXxx inside. See details below.
The rules `structcheck` and `unused` highlight the 'hack' with using
_msgpack struct{} `msgpack:",asArray"`. The workaround with `//nolint`
is not the best way to suppress it, cause this comment gets rendered
by godoc and there is no way to make it invisible. For details see
golang/go#20925.

Suppressed the highlighting of error check in all methods,
having encodeXxx inside. For now these methods are not able to
return any error cause of internal implementation of writer
interface (see smallbuf.go). For future, if the implementation of writer
will be changed, and there will be a need to check errors, we must think
about how to say to compiler that the error check is 'unlikely'.

Fixed the use of time package API, all places with calls of
time.Now().Sub(). Now time package propose the explicit time.Until().

Replaced all calls of Errorf() with Fatalf() in tests. That change
prevents nil dereferences below in the code and stops test function
execution, where it is expected in tests.

Suppressed the highlighting of all unused constants and functions
(Rules structcheck,unused in golangci-lint).

Fixed calling of Fatalf from non-testing goroutine in queue tests.
It is not a valid way to stop test from another goroutine.

Closes #142
Closes #150

.github/workflows/check.yaml

@@ -39,4 +39,4 @@ jobs:
       - name: golangci-lint
         uses: golangci/golangci-lint-action@v2
         with:
-          args: --issues-exit-code=0 -E gofmt
+          args: --disable errcheck,unused,structcheck -E gofmt

connection.go

@@ -495,7 +495,7 @@ func (conn *Connection) createConnection(reconnect bool) (err error) {
 		conn.notify(ReconnectFailed)
 		reconnects++
 		conn.mutex.Unlock()
-		time.Sleep(now.Add(conn.opts.Reconnect).Sub(time.Now()))
+		time.Sleep(time.Until(now.Add(conn.opts.Reconnect)))
 		conn.mutex.Lock()
 	}
 	if conn.state == connClosed {
@@ -688,7 +688,7 @@ func (conn *Connection) newFuture(requestCode int32) (fut *Future) {
 	*pair.last = fut
 	pair.last = &fut.next
 	if conn.opts.Timeout > 0 {
-		fut.timeout = time.Now().Sub(epoch) + conn.opts.Timeout
+		fut.timeout = time.Until(epoch) + conn.opts.Timeout
 	}
 	shard.rmut.Unlock()
 	if conn.rlimit != nil && conn.opts.RLimitAction == RLimitWait {
@@ -796,9 +796,9 @@ func (conn *Connection) timeouts() {
 			return
 		case <-t.C:
 		}
-		minNext := time.Now().Sub(epoch) + timeout
+		minNext := time.Until(epoch) + timeout
 		for i := range conn.shard {
-			nowepoch = time.Now().Sub(epoch)
+			nowepoch = time.Until(epoch)
 			shard := &conn.shard[i]
 			for pos := range shard.requests {
 				shard.rmut.Lock()
@@ -825,7 +825,7 @@ func (conn *Connection) timeouts() {
 				shard.rmut.Unlock()
 			}
 		}
-		nowepoch = time.Now().Sub(epoch)
+		nowepoch = time.Until(epoch)
 		if nowepoch+time.Microsecond < minNext {
 			t.Reset(minNext - nowepoch)
 		} else {

connection_pool/example_test.go

@@ -11,7 +11,7 @@ import (
 type Tuple struct {
 	// Instruct msgpack to pack this struct as array, so no custom packer
 	// is needed.
-	_msgpack struct{} `msgpack:",asArray"` //nolint: structcheck,unused
+	_msgpack struct{} `msgpack:",asArray"`
 	Key      string
 	Value    string
 }
@@ -53,7 +53,7 @@ func ExampleConnectionPool_Select() {
 		return
 	}
 	// Insert a new tuple {"key2", "value2"}.
-	_, err = conn.Insert(spaceName,  &Tuple{Key: "key2", Value: "value2"})
+	_, err = conn.Insert(spaceName, &Tuple{Key: "key2", Value: "value2"})
 	if err != nil {
 		fmt.Printf("Failed to insert: %s", err.Error())
 		return
@@ -114,7 +114,7 @@ func ExampleConnectionPool_SelectTyped() {
 		return
 	}
 	// Insert a new tuple {"key2", "value2"}.
-	_, err = conn.Insert(spaceName,  &Tuple{Key: "key2", Value: "value2"})
+	_, err = conn.Insert(spaceName, &Tuple{Key: "key2", Value: "value2"})
 	if err != nil {
 		fmt.Printf("Failed to insert: %s", err.Error())
 		return
@@ -176,7 +176,7 @@ func ExampleConnectionPool_SelectAsync() {
 		return
 	}
 	// Insert a new tuple {"key2", "value2"}.
-	_, err = conn.Insert(spaceName,  &Tuple{Key: "key2", Value: "value2"})
+	_, err = conn.Insert(spaceName, &Tuple{Key: "key2", Value: "value2"})
 	if err != nil {
 		fmt.Printf("Failed to insert: %s", err.Error())
 		return
@@ -196,7 +196,7 @@ func ExampleConnectionPool_SelectAsync() {
 		spaceName, indexName, 0, 1, tarantool.IterEq,
 		[]interface{}{"key2"}, connection_pool.RW)
 	futs[2] = pool.SelectAsync(
-		spaceName, indexName, 0, 1,tarantool.IterEq,
+		spaceName, indexName, 0, 1, tarantool.IterEq,
 		[]interface{}{"key3"}, connection_pool.RW)
 	var t []Tuple
 	err = futs[0].GetTyped(&t)

example_test.go

@@ -70,6 +70,7 @@ func ExampleConnection_SelectTyped() {
 	// response is [{{} 1111 hello world}]
 }
 
+//nolint
 func ExampleConnection_SelectAsync() {
 	conn := example_connect()
 	defer conn.Close()

multi/multi_test.go

@@ -27,21 +27,21 @@ var connOptsMulti = OptsMulti{
 func TestConnError_IncorrectParams(t *testing.T) {
 	multiConn, err := Connect([]string{}, tarantool.Opts{})
 	if err == nil {
-		t.Errorf("err is nil with incorrect params")
+		t.Fatalf("err is nil with incorrect params")
 	}
 	if multiConn != nil {
-		t.Errorf("conn is not nill with incorrect params")
+		t.Fatalf("conn is not nill with incorrect params")
 	}
 	if err.Error() != "addrs should not be empty" {
 		t.Errorf("incorrect error: %s", err.Error())
 	}
 
 	multiConn, err = ConnectWithOpts([]string{server1}, tarantool.Opts{}, OptsMulti{})
 	if err == nil {
-		t.Errorf("err is nil with incorrect params")
+		t.Fatal("err is nil with incorrect params")
 	}
 	if multiConn != nil {
-		t.Errorf("conn is not nill with incorrect params")
+		t.Fatal("conn is not nill with incorrect params")
 	}
 	if err.Error() != "wrong check timeout, must be greater than 0" {
 		t.Errorf("incorrect error: %s", err.Error())

queue/example_test.go

@@ -16,6 +16,7 @@ import (
 	"github.com/tarantool/go-tarantool/queue"
 )
 
+//nolint
 // Example demonstrates an operations like Put and Take with queue.
 func Example_simpleQueue() {
 	cfg := queue.Cfg{

queue/queue.go

@@ -339,6 +339,7 @@ type queueData struct {
 	result interface{}
 }
 
+//nolint
 func (qd *queueData) DecodeMsgpack(d *msgpack.Decoder) error {
 	var err error
 	var l int

queue/queue_test.go

@@ -630,7 +630,7 @@ func TestFifoQueue_Release(t *testing.T) {
 func TestTtlQueue(t *testing.T) {
 	conn, err := Connect(server, opts)
 	if err != nil {
-		t.Errorf("Failed to connect: %s", err.Error())
+		t.Fatalf("Failed to connect: %s", err.Error())
 		return
 	}
 	defer conn.Close()
@@ -683,11 +683,11 @@ func TestTtlQueue(t *testing.T) {
 func TestTtlQueue_Put(t *testing.T) {
 	conn, err := Connect(server, opts)
 	if err != nil {
-		t.Errorf("Failed to connect: %s", err.Error())
+		t.Fatalf("Failed to connect: %s", err.Error())
 		return
 	}
 	if conn == nil {
-		t.Errorf("conn is nil after Connect")
+		t.Fatalf("conn is nil after Connect")
 		return
 	}
 	defer conn.Close()
@@ -755,11 +755,11 @@ func TestTtlQueue_Put(t *testing.T) {
 func TestUtube_Put(t *testing.T) {
 	conn, err := Connect(server, opts)
 	if err != nil {
-		t.Errorf("Failed to connect: %s", err.Error())
+		t.Fatalf("Failed to connect: %s", err.Error())
 		return
 	}
 	if conn == nil {
-		t.Errorf("conn is nil after Connect")
+		t.Fatalf("conn is nil after Connect")
 		return
 	}
 	defer conn.Close()
@@ -794,16 +794,22 @@ func TestUtube_Put(t *testing.T) {
 		t.Fatalf("Failed put task to queue: %s", err.Error())
 	}
 
+	errChan := make(chan struct{})
 	go func() {
 		t1, err := q.TakeTimeout(2 * time.Second)
 		if err != nil {
-			t.Fatalf("Failed to take task from utube: %s", err.Error())
+			t.Errorf("Failed to take task from utube: %s", err.Error())
+			errChan <- struct{}{}
+			return
 		}
 
 		time.Sleep(2 * time.Second)
 		if err := t1.Ack(); err != nil {
-			t.Fatalf("Failed to ack task: %s", err.Error())
+			t.Errorf("Failed to ack task: %s", err.Error())
+			errChan <- struct{}{}
+			return
 		}
+		close(errChan)
 	}()
 
 	time.Sleep(100 * time.Millisecond)
@@ -817,6 +823,9 @@ func TestUtube_Put(t *testing.T) {
 		t.Fatalf("Failed to ack task: %s", err.Error())
 	}
 	end := time.Now()
+	if _, ok := <-errChan; ok {
+		t.Fatalf("One of tasks failed")
+	}
 	if math.Abs(float64(end.Sub(start)-2*time.Second)) > float64(200*time.Millisecond) {
 		t.Fatalf("Blocking time is less than expected: actual = %.2fs, expected = 1s", end.Sub(start).Seconds())
 	}

response.go

@@ -15,6 +15,7 @@ type Response struct {
 	buf  smallBuf
 }
 
+//nolint: unused
 func (resp *Response) fill(b []byte) {
 	resp.buf.b = b
 }

schema.go

@@ -50,6 +50,7 @@ type IndexField struct {
 	Type string
 }
 
+//nolint: varcheck,deadcode
 const (
 	maxSchemas = 10000
 	spaceSpId  = 280