GODRIVER-3173 Shore up testing

Author: prestonvasquez

testdata/specifications

@@ -367,6 +367,9 @@ func TestCMAPProse(t *testing.T) {
 
 		// There should be 0 ConnectionPendingResponseSucceeded event.
 		require.Len(t, poolEventsByType[event.ConnectionPendingResponseSucceeded], 0)
+
+		// The connection should have been closed.
+		require.Len(t, poolEventsByType[event.ConnectionClosed], 1)
 	})
 
 	t.Run("connection attempts peek and succeeds", func(t *testing.T) {
@@ -465,6 +468,9 @@ func TestCMAPProse(t *testing.T) {
 		assert.Equal(t, conn.driverConnectionID, succeeded[0].ConnectionID)
 		assert.Equal(t, requestID, succeeded[0].RequestID)
 		assert.Greater(t, int(succeeded[0].Duration), 0)
+
+		// The connection should not have been closed.
+		require.Len(t, poolEventsByType[event.ConnectionClosed], 0)
 	})
 }
 

x/mongo/driver/topology/cmap_prose_test.go

@@ -1035,7 +1035,14 @@ func awaitPendingResponse(ctx context.Context, pool *pool, conn *connection) err
 			_ = pool.checkInNoEvent(conn)
 		}()
 
-		if netErr, ok := err.(net.Error); ok && !netErr.Timeout() {
+		isCSOTTimeout := func(err error) bool {
+			// If the error was a timeout error, instead of closing the
+			// connection mark it as awaiting response so the pool can read the
+			// response before making it available to other operations.
+			nerr := net.Error(nil)
+			return errors.As(err, &nerr) && nerr.Timeout()
+		}
+		if !isCSOTTimeout(err) {
 			if err := conn.close(); err != nil {
 				return err
 			}