fix: tests refactored

Now 3 test, each cover distinct case.

Fixes (#457)

Author: ermyar

tarantool_test.go

@@ -2744,31 +2744,41 @@ func TestClientRequestObjectsWithPassedCanceledContext(t *testing.T) {
 	}
 }
 
-func TestComparableCanceledContextErrors(t *testing.T) {
+// Checking comparable with simple context.WithCancel.
+func TestComparableErrorsCanceledContext(t *testing.T) {
 	conn := test_helpers.ConnectWithValidation(t, dialer, opts)
 	defer conn.Close()
 
-	// Checking comparable with simple context.WithCancel.
 	ctx, cancel := context.WithCancel(context.Background())
 	req := NewPingRequest().Context(ctx)
 	cancel()
 	_, err := conn.Do(req).Get()
 	require.True(t, errors.Is(err, context.Canceled), err.Error())
+}
+
+// Checking comparable with simple context.WithTimeout.
+func TestComparableErrorsTimeoutContext(t *testing.T) {
+	conn := test_helpers.ConnectWithValidation(t, dialer, opts)
+	defer conn.Close()
 
-	// Checking comparable with simple context.WithTimeout.
 	timeout := time.Nanosecond
-	ctx, cancel = context.WithTimeout(context.Background(), timeout)
-	req = NewPingRequest().Context(ctx)
+	ctx, cancel := context.WithTimeout(context.Background(), timeout)
+	req := NewPingRequest().Context(ctx)
 	defer cancel()
-	_, err = conn.Do(req).Get()
+	_, err := conn.Do(req).Get()
 	require.True(t, errors.Is(err, context.DeadlineExceeded), err.Error())
+}
+
+// Checking comparable with context.WithCancelCause.
+// Shows ability to compare with custom errors (also with ClientError).
+func TestComparableErrorsCancelCauseContext(t *testing.T) {
+	conn := test_helpers.ConnectWithValidation(t, dialer, opts)
+	defer conn.Close()
 
-	// Checking comparable with context.WithCancelCause.
-	// Shows ability to compare with custom errors (also with ClientError).
 	ctxCause, cancelCause := context.WithCancelCause(context.Background())
-	req = NewPingRequest().Context(ctxCause)
+	req := NewPingRequest().Context(ctxCause)
 	cancelCause(ClientError{ErrConnectionClosed, "something went wrong"})
-	_, err = conn.Do(req).Get()
+	_, err := conn.Do(req).Get()
 	var tmpErr ClientError
 	require.True(t, errors.As(err, &tmpErr), tmpErr.Error())
 }