初版功能完成

internal/subnetgateway/udprelay/relay_test.go

@@ -0,0 +1,44 @@
+package udprelay
+
+import (
+	"context"
+	"net"
+	"testing"
+	"time"
+)
+
+func TestRelayIdleTimeoutIsNormalFlowCompletion(t *testing.T) {
+	leftRelay, leftPeer := net.Pipe()
+	rightRelay, rightPeer := net.Pipe()
+	defer leftPeer.Close()
+	defer rightPeer.Close()
+	done := make(chan error, 1)
+	go func() { done <- Relay(context.Background(), leftRelay, rightRelay, 20*time.Millisecond) }()
+	select {
+	case err := <-done:
+		if err != nil {
+			t.Fatalf("idle Relay returned %v, want nil", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("idle Relay did not reclaim the flow")
+	}
+}
+
+func TestRelayReturnsParentCancellation(t *testing.T) {
+	leftRelay, leftPeer := net.Pipe()
+	rightRelay, rightPeer := net.Pipe()
+	defer leftPeer.Close()
+	defer rightPeer.Close()
+	ctx, cancel := context.WithCancel(context.Background())
+	done := make(chan error, 1)
+	go func() { done <- Relay(ctx, leftRelay, rightRelay, time.Hour) }()
+	cancel()
+	select {
+	case err := <-done:
+		if err != context.Canceled {
+			t.Fatalf("Relay cancellation = %v, want context.Canceled", err)
+		}
+	case <-time.After(time.Second):
+		t.Fatal("canceled Relay did not stop")
+	}
+}