add cache invalidation test

postgres/transport_test.go

@@ -76,6 +76,56 @@ func TestTransport(t *testing.T) {
 	speedupIsAboveMinRatio(t, cold, cached, 0.75)
 }
 
+func TestTransportInvalidateAllResponses(t *testing.T) {
+	t.Setenv("TESTCONTAINERS_RYUK_DISABLED", "true")
+	container, fn := startContainer(t, "user", "password")
+	defer fn()
+
+	connstr, err := container.ConnectionString(t.Context(), "sslmode=disable")
+	if err != nil {
+		t.Fatalf("generating postgres connection string: %v", err)
+	}
+
+	delay := 3 * time.Second
+	srv := httptest.NewServer(delayedResponse(delay))
+	defer srv.Close()
+
+	db, err := pgx.Connect(t.Context(), connstr)
+	if err != nil {
+		t.Fatalf("connecting to postgres database: %v", err)
+	}
+
+	tr, err := httpcache.NewTransport(t.Context(), Connection{db}, nil)
+	if err != nil {
+		t.Fatalf("couldn't initialize transport for test: %v", err)
+	}
+
+	client := &http.Client{Transport: tr}
+
+	_, err = measureDuration(get(client, srv.URL))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	_, err = measureDuration(get(client, srv.URL))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if err := tr.InvalidateAllResponses(t.Context()); err != nil {
+		t.Fatalf("couldn't invalidate all responses in the cache: %v", err)
+	}
+
+	cold, err := measureDuration(get(client, srv.URL))
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	if cold <= (delay) {
+		t.Fatalf("expected cold latency to be lower than or equal to %d, got %d\n", delay, cold)
+	}
+}
+
 func speedupIsAboveMinRatio(t *testing.T, cold, cached time.Duration, minRatio float64) {
 	t.Helper()