add string type enums and retry config

pkg/client/client_test.go

@@ -144,6 +144,61 @@ func TestClientWingbitsEndpoints(t *testing.T) {
 	}
 }
 
+func TestClientRetry(t *testing.T) {
+	// Fail with 503 for the first two attempts, then succeed; the client must
+	// retry past the failures and return the eventual body.
+	var hits int
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		if hits++; hits <= 2 {
+			http.Error(w, "warming up", http.StatusServiceUnavailable)
+			return
+		}
+		w.Write([]byte(`{}`))
+	}))
+	t.Cleanup(srv.Close)
+
+	host, port := splitHostPort(t, strings.TrimPrefix(srv.URL, "http://"))
+	c, err := New(
+		WithWingbitsEndpoint(Endpoint{Host: host, Port: port}),
+		WithRetry(RetryConfig{MaxRetries: 3, BaseDelay: time.Millisecond, MaxDelay: 5 * time.Millisecond}),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := c.Status(context.Background()); err != nil {
+		t.Fatalf("status after retries: %v", err)
+	}
+	if hits != 3 {
+		t.Fatalf("expected 3 attempts, got %d", hits)
+	}
+}
+
+func TestClientRetryGivesUp(t *testing.T) {
+	// A 404 is not retryable: the client must fail after a single attempt even
+	// with retries configured.
+	var hits int
+	srv := httptest.NewServer(http.HandlerFunc(func(w http.ResponseWriter, _ *http.Request) {
+		hits++
+		http.Error(w, "nope", http.StatusNotFound)
+	}))
+	t.Cleanup(srv.Close)
+
+	host, port := splitHostPort(t, strings.TrimPrefix(srv.URL, "http://"))
+	c, err := New(
+		WithWingbitsEndpoint(Endpoint{Host: host, Port: port}),
+		WithRetry(RetryConfig{MaxRetries: 3, BaseDelay: time.Millisecond}),
+	)
+	if err != nil {
+		t.Fatal(err)
+	}
+	if _, err := c.Status(context.Background()); err == nil {
+		t.Fatal("expected error on 404")
+	}
+	if hits != 1 {
+		t.Fatalf("expected 1 attempt for non-retryable status, got %d", hits)
+	}
+}
+
 func TestPollAircraft(t *testing.T) {
 	c := newTestClient(t)
 	ctx := t.Context()