Implement `GetRejectedConnectionsCount` function (#1704)

* Implement `GetRejectedConnectionsCount`

* Implement test for `GetRejectedConnectionsCount`

1 files changed, 56 insertions, 0 deletions

diff --git a/server_test.go b/server_test.go
index efc126f..58454db 100644
--- a/server_test.go
+++ b/server_test.go
@@ -1016,6 +1016,62 @@ func TestServerConcurrencyLimit(t *testing.T) {
 	}
 }
 
+func TestRejectedRequestsCount(t *testing.T) {
+	t.Parallel()
+
+	s := &Server{
+		Handler: func(ctx *RequestCtx) {
+			ctx.WriteString("OK") //nolint:errcheck
+		},
+		Concurrency: 1,
+		Logger:      &testLogger{},
+	}
+
+	ln := fasthttputil.NewInmemoryListener()
+
+	serverCh := make(chan struct{})
+	go func() {
+		if err := s.Serve(ln); err != nil {
+			t.Errorf("unexpected error: %v", err)
+		}
+		close(serverCh)
+	}()
+
+	clientCh := make(chan struct{})
+	expectedCount := 5
+	go func() {
+		for i := 0; i < expectedCount+1; i++ {
+			_, err := ln.Dial()
+			if err != nil {
+				t.Errorf("unexpected error: %v", err)
+			}
+		}
+
+		if cnt := s.GetRejectedConnectionsCount(); cnt != uint32(expectedCount) {
+			t.Errorf("unexpected rejected connections count: %d. Expecting %d",
+				cnt, expectedCount)
+		}
+
+		close(clientCh)
+	}()
+
+	select {
+	case <-clientCh:
+	case <-time.After(time.Second):
+		t.Fatal("timeout")
+	}
+
+	if err := ln.Close(); err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+
+	select {
+	case <-serverCh:
+	case <-time.After(time.Second):
+		t.Fatal("timeout")
+	}
+}
+
 func TestServerWriteFastError(t *testing.T) {
 	t.Parallel()