api: block Connect() on failure if Reconnect > 0

[ImeevMA]

This patch makes Connect() retry connection attempts if opts.Reconnect is greater than 0. The delay between connection attempts is opts.Reconnect. If opts.MaxReconnects > 0 then the maximum number of attempts is equal to it, otherwise the maximum number of attempts is unlimited. Connect() now also blocks until a connection is established, provided context is cancelled or the number of attempts is exhausted.

Closes #436

What has been done? Why? What problem is being solved?

Connect() now handles connection retries on its own. This simplifies connecting to Tarantool instances when there is no guarantee that the connection will be established on the first try.

I didn't forget about (remove if it is not applicable):

• Tests (see documentation for a testing package)
• Changelog (see documentation for changelog format)
• Documentation (see documentation for documentation style guide)

Related issues: #436

[oleg-jukovec]

Thanks for the patch. Overall the idea is good, but there are a couple of issues with the implementation.

[oleg-jukovec]

I have a few non-critical comments.

[patapenka-alexey]

Suggested change

	if err.Error() != exp {
	t.Fatalf("Expected '%s', got '%v'", exp, err)
	}
	assert.EqualError(t, err, exp)

Maybe we can use this? And in all other places.

[ImeevMA]

Fixed:

diff --git a/tarantool_test.go b/tarantool_test.go
index 741e0a4..3f1e90e 100644
--- a/tarantool_test.go
+++ b/tarantool_test.go
@@ -4013,15 +4013,9 @@ func TestConnectIsBlocked(t *testing.T) {
 	reconnectOpts.Reconnect = 100 * time.Millisecond
 	reconnectOpts.MaxReconnects = 100
 	conn, err := Connect(ctx, mockDialer, reconnectOpts)
-	if err != nil {
-		t.Fatalf("Connection was not established: %v", err)
-	}
-
+	assert.Nil(t, err)
 	conn.Close()
-
-	if counter < 10 {
-		t.Fatalf("Expected no less than 10, got %d", counter)
-	}
+	assert.GreaterOrEqual(t, counter, 10)
 }
 
 func TestConnectIsBlockedUntilContextExpires(t *testing.T) {
@@ -4037,14 +4031,8 @@ func TestConnectIsBlockedUntilContextExpires(t *testing.T) {
 	reconnectOpts.Reconnect = 100 * time.Millisecond
 	reconnectOpts.MaxReconnects = 100
 	_, err := Connect(ctx, testDialer, reconnectOpts)
-	if err == nil {
-		t.Fatal("Connection was unexpectedly established.")
-	}
-
-	exp := "failed to dial: dial tcp 127.0.0.1:3015: i/o timeout"
-	if err.Error() != exp {
-		t.Fatalf("Expected '%s', got '%v'", exp, err)
-	}
+	assert.NotNil(t, err)
+	assert.ErrorContains(t, err, "failed to dial: dial tcp 127.0.0.1:3015: i/o timeout")
 }
 
 func TestConnectIsUnblockedAfterMaxAttempts(t *testing.T) {
@@ -4060,14 +4048,8 @@ func TestConnectIsUnblockedAfterMaxAttempts(t *testing.T) {
 	reconnectOpts.Reconnect = 100 * time.Millisecond
 	reconnectOpts.MaxReconnects = 1
 	_, err := Connect(ctx, testDialer, reconnectOpts)
-	if err == nil {
-		t.Fatal("Connection was unexpectedly established.")
-	}
-
-	exp := "last reconnect failed"
-	if !strings.Contains(err.Error(), exp) {
-		t.Fatalf("Expected '%s', got '%v'", exp, err)
-	}
+	assert.NotNil(t, err)
+	assert.ErrorContains(t, err, "last reconnect failed")
 }
 
 func buildSidecar(dir string) error {

[patapenka-alexey]

LGTM!