rproxy tests give a loaded host time before their limits run out (closes #185) (#186)

internal/rproxy/limits_test.go

@@ -1,7 +1,9 @@
 package rproxy_test
 
 import (
+	"bufio"
 	"bytes"
+	"errors"
 	"io"
 	"log/slog"
 	"net"
@@ -602,10 +604,12 @@ func TestAnAppTooSlowToAnswerIsAnswered504(t *testing.T) {
 func TestAnAppTooSlowToFinishItsAnswerIsCutOff(t *testing.T) {
 	t.Parallel()
 
+	const start = "the start"
+
 	release := make(chan struct{})
 	servewaf := startServeWAF(t, allow)
 	app := startApp(t, func(w http.ResponseWriter, _ *http.Request) {
-		_, _ = io.WriteString(w, "the start")
+		_, _ = io.WriteString(w, start)
 		_ = http.NewResponseController(w).Flush()
 
 		<-release
@@ -613,17 +617,29 @@ func TestAnAppTooSlowToFinishItsAnswerIsCutOff(t *testing.T) {
 
 	t.Cleanup(func() { close(release) })
 
+	// The time limit is long enough for a loaded host to pass on the start of the
+	// answer before it runs out.
 	addr, _ := startRProxy(t, servewaf.URL, app.URL, map[string]string{
-		maxResponseTime: "300",
+		maxResponseTime: "3000",
 	})
 
 	conn := dial(t, addr)
 	send(t, conn, "GET / HTTP/1.1\r\nHost: site.example\r\n\r\n")
 
-	// dial's deadline ends this read with an error if the connection stays open.
-	_, err := io.ReadAll(conn)
+	res, err := http.ReadResponse(bufio.NewReader(conn), nil)
 	if err != nil {
-		t.Errorf("read: %v, want the connection closed", err)
+		t.Fatalf("read the answer: %v", err)
+	}
+
+	// The body breaks off when rproxy closes the connection. If the connection
+	// stays open, dial's deadline ends this read with a timeout instead.
+	body, err := io.ReadAll(res.Body)
+	_ = res.Body.Close()
+
+	if res.StatusCode != http.StatusOK || string(body) != start ||
+		!errors.Is(err, io.ErrUnexpectedEOF) {
+		t.Errorf("answered %d %q (%v), want the app's 200 %q, then the connection closed",
+			res.StatusCode, body, err, start)
 	}
 
 	if report := servewaf.report(t); report.Status != http.StatusOK {
@@ -651,8 +667,10 @@ func TestAVisitorTooSlowToTakeTheAnswerIsCutOff(t *testing.T) {
 			}
 		}
 	})
+	// The time limit is long enough for a loaded host to start passing on the
+	// answer before it runs out.
 	addr, out := startRProxy(t, servewaf.URL, app.URL, map[string]string{
-		maxResponseTime: "500",
+		maxResponseTime: "3000",
 	})
 
 	// The visitor asks, and never reads the answer.
@@ -793,8 +811,10 @@ func TestAVisitorThatStopsSendingGetsAnAnswerRProxyGivesByTheDeadline(t *testing
 
 			servewaf := startServeWAF(t, deny)
 			app := startApp(t, greet)
+			// The time limit is long enough for a loaded host to read the first part of
+			// the body before it runs out.
 			addr, _ := startRProxy(t, servewaf.URL, app.URL, map[string]string{
-				maxRequestTime: "500",
+				maxRequestTime: "3000",
 			})
 
 			// Go's server waits for a little of the body left before it sends an answer,

internal/rproxy/rproxy_test.go

@@ -1353,8 +1353,10 @@ func TestAReportServeWAFLeavesUnansweredIsDroppedAtTheTimeLimit(t *testing.T) {
 		})
 
 	app := startApp(t, greet)
+	// The time limit is long enough for a loaded host to answer the question before
+	// it runs out.
 	addr, out := startRProxy(t, backend, app.URL, map[string]string{
-		timeoutSetting: "1000",
+		timeoutSetting: "3000",
 	})
 
 	t.Cleanup(func() { close(release) })