Additional transport test

Add test for a case when rate limiter does not allow a request.

internal/proxy/transport_test.go

@@ -3,6 +3,7 @@ package proxy
 import (
 	"net/http"
 	"testing"
+	"time"
 
 	"github.com/rekby/lets-proxy2/internal/th"
 
@@ -37,3 +38,25 @@ func TestTransport_GetTransport(t *testing.T) {
 	td.Cmp(httpTransport.TLSClientConfig.ServerName, "www.ru")
 	td.Cmp(httpTransport.TLSClientConfig.InsecureSkipVerify, true)
 }
+
+func TestTransport_RoundTrip(t *testing.T) {
+	t.Run("should return status 429 when request is not allowed by rate limiter", func(t *testing.T) {
+		td := testdeep.NewT(t)
+		rateLimiter, err := NewRateLimiter(RateLimitParams{
+			// -1 force rate limiter to never allow a request
+			RateLimit:  -1,
+			TimeWindow: time.Second,
+			Burst:      1,
+			CacheSize:  100,
+		})
+		td.CmpNoError(err)
+
+		tr := Transport{RateLimiter: rateLimiter}
+		req, _ := http.NewRequest(http.MethodGet, "http://www.ru", nil)
+
+		resp, err := tr.RoundTrip(req)
+
+		td.CmpNoError(err)
+		td.Cmp(resp.StatusCode, http.StatusTooManyRequests, "should return '429 Too Many Request'")
+	})
+}