test(compat): add deterministic local fixtures

Co-authored-by: naiba/CloudCode <hi+cloudcode@nai.ba>

integration/agentcompat/internal/fixture/nat_echo_test.go

@@ -0,0 +1,84 @@
+package fixture
+
+import (
+	"bufio"
+	"context"
+	"fmt"
+	"io"
+	"net"
+	"net/http"
+	"strings"
+	"testing"
+	"time"
+)
+
+func TestFixture_NATEchoHalfClose(t *testing.T) {
+	// Given
+	backend, err := StartNATHalfCloseEchoBackend()
+	requireNoFixtureError(t, err)
+	t.Cleanup(func() { requireNoFixtureError(t, backend.Close()) })
+	connection, err := net.DialTimeout("tcp", backend.Address(), time.Second)
+	requireNoFixtureError(t, err)
+	tcpConnection := connection.(*net.TCPConn)
+	defer tcpConnection.Close()
+	requireNoFixtureError(t, tcpConnection.SetDeadline(time.Now().Add(2*time.Second)))
+	requestBody := "half-closed"
+	request := fmt.Sprintf("POST /echo?case=half-close HTTP/1.1\r\nHost: nat.invalid\r\nX-AgentCompat-Echo: fixture\r\nContent-Length: %d\r\nConnection: close\r\n\r\n%s", len(requestBody), requestBody)
+
+	// When
+	_, err = io.WriteString(tcpConnection, request)
+	requireNoFixtureError(t, err)
+	requireNoFixtureError(t, tcpConnection.CloseWrite())
+	response, err := http.ReadResponse(bufio.NewReader(tcpConnection), nil)
+	requireNoFixtureError(t, err)
+	responseBody, err := io.ReadAll(response.Body)
+	requireNoFixtureError(t, err)
+	requireNoFixtureError(t, response.Body.Close())
+	ctx, cancel := context.WithTimeout(context.Background(), time.Second)
+	defer cancel()
+	record, err := backend.WaitRequest(ctx)
+	requireNoFixtureError(t, err)
+
+	// Then
+	const expected = "method=POST\npath=/echo?case=half-close\nhost=nat.invalid\nx-agentcompat-echo=fixture\nbody=half-closed\n"
+	if response.StatusCode != http.StatusOK || string(responseBody) != expected {
+		t.Fatalf("NAT echo response = %d %q", response.StatusCode, responseBody)
+	}
+	if !record.RequestHalfClosed {
+		t.Fatal("backend responded before observing request half-close")
+	}
+	if record.Method != "POST" || record.Path != "/echo?case=half-close" || record.Host != "nat.invalid" || record.HeaderValue != "fixture" || string(record.Body) != requestBody {
+		t.Fatalf("NAT request record = %+v", record)
+	}
+}
+
+func TestFixture_NATEcho(t *testing.T) {
+	// Given
+	backend, err := StartNATEchoBackend()
+	requireNoFixtureError(t, err)
+	t.Cleanup(func() { requireNoFixtureError(t, backend.Close()) })
+	ctx, cancel := context.WithTimeout(context.Background(), 2*time.Second)
+	defer cancel()
+	request, err := http.NewRequestWithContext(ctx, http.MethodPut, "http://"+backend.Address()+"/echo?case=ordinary", strings.NewReader("ordinary"))
+	requireNoFixtureError(t, err)
+	request.Host = "nat.invalid"
+	request.Header.Set("X-AgentCompat-Echo", "fixture")
+
+	// When
+	response, err := http.DefaultClient.Do(request)
+	requireNoFixtureError(t, err)
+	responseBody, err := io.ReadAll(response.Body)
+	requireNoFixtureError(t, err)
+	requireNoFixtureError(t, response.Body.Close())
+	record, err := backend.WaitRequest(ctx)
+	requireNoFixtureError(t, err)
+
+	// Then
+	const expected = "method=PUT\npath=/echo?case=ordinary\nhost=nat.invalid\nx-agentcompat-echo=fixture\nbody=ordinary\n"
+	if response.StatusCode != http.StatusOK || string(responseBody) != expected {
+		t.Fatalf("NAT echo response = %d %q", response.StatusCode, responseBody)
+	}
+	if record.RequestHalfClosed || record.Method != http.MethodPut || record.Host != "nat.invalid" {
+		t.Fatalf("NAT request record = %+v", record)
+	}
+}