pgwire: increase timeout and add Error() call

This test seems to deadlock sporadically under remote execution. I
believe the connection is timing out, which due to the way this test was
written causes it to deadlock. I'm increasing the timeout to attempt to
increase reliability, and separately, we also add a call to `Error()`
to mark the test as failed should the connection fail.

Additionally, getSessionArgs was updated to return a fake pgwire
connection handshake response, so that the test could assert that the
connection succeeded.

Closes #118741.

Epic: None
Release note: None

Author: rickystewart

pkg/sql/pgwire/conn_test.go

@@ -1626,10 +1626,12 @@ func TestParseClientProvidedSessionParameters(t *testing.T) {
 		t.Run(tc.desc, func(t *testing.T) {
 
 			var netConn net.Conn
-			wg := sync.WaitGroup{}
-			wg.Add(1)
+			clientDone := sync.WaitGroup{}
+			clientDone.Add(1)
+			serverReceivedConn := sync.WaitGroup{}
+			serverReceivedConn.Add(1)
 			go func(query string) {
-				defer wg.Done()
+				defer clientDone.Done()
 				ctx, cancel := context.WithTimeout(context.Background(), 500*time.Millisecond)
 				defer cancel()
 				url := fmt.Sprintf("%s&%s", baseURL, query)
@@ -1641,6 +1643,7 @@ func TestParseClientProvidedSessionParameters(t *testing.T) {
 				// ignore the error because there is no answer from the server, we are
 				// interested in parsing session arguments only. We close the connection
 				// immediately, since getSessionArgs is blocking.
+				serverReceivedConn.Wait()
 				_ = netConn.Close()
 				_ = c.Close(ctx)
 
@@ -1652,10 +1655,15 @@ func TestParseClientProvidedSessionParameters(t *testing.T) {
 					t.Error("pgconn asyncClose did not clean up on time")
 				}
 			}(tc.query)
-			// Wait for the client to connect and perform the handshake.
+			// Wait for the client to connect and perform the handshake. Use a
+			// closure so that the WaitGroup is marked as done even if there's a
+			// panic.
 			var args sql.SessionArgs
-			netConn, args, err = getSessionArgs(ln, true /* trustRemoteAddr */)
-			wg.Wait()
+			func() {
+				defer serverReceivedConn.Done()
+				netConn, args, err = getSessionArgs(ln, true /* trustRemoteAddr */)
+			}()
+			clientDone.Wait()
 			tc.assert(t, args, err)
 		})
 	}