#13: implement Outbound Queue, Retry Backoff Engine & DSN Bounce Generator (RFC 3464)

services/protocols/internal/application/usecase/outbound_worker_test.go

@@ -0,0 +1,95 @@
+package usecase
+
+import (
+	"bytes"
+	"context"
+	"io"
+	"strings"
+	"testing"
+	"time"
+
+	"github.com/google/uuid"
+
+	"lambdamail/protocols/internal/application/port"
+	"lambdamail/protocols/internal/domain/entity"
+)
+
+type fakeOutboundRepo struct {
+	jobs []*entity.OutboundJob
+}
+
+func (f *fakeOutboundRepo) Enqueue(_ context.Context, job *entity.OutboundJob) error {
+	f.jobs = append(f.jobs, job)
+	return nil
+}
+
+func (f *fakeOutboundRepo) FetchNextReady(_ context.Context, _ string, _ int) ([]*entity.OutboundJob, error) {
+	var ready []*entity.OutboundJob
+	for _, j := range f.jobs {
+		if j.Status == entity.OutboundJobStatusQueued || j.Status == entity.OutboundJobStatusDeferred {
+			ready = append(ready, j)
+		}
+	}
+	return ready, nil
+}
+
+func (f *fakeOutboundRepo) UpdateJob(_ context.Context, job *entity.OutboundJob) error {
+	for i, j := range f.jobs {
+		if j.ID == job.ID {
+			f.jobs[i] = job
+			break
+		}
+	}
+	return nil
+}
+
+type fakeMXResolver struct {
+	hosts []string
+}
+
+func (f *fakeMXResolver) LookupMX(_ context.Context, _ string) ([]string, error) {
+	return f.hosts, nil
+}
+
+type fakeBlobReader struct {
+	payload []byte
+}
+
+func (f *fakeBlobReader) ReadByID(_ context.Context, _ uuid.UUID) ([]byte, error) {
+	return f.payload, nil
+}
+
+func TestOutboundWorker_DeferralAndPermanentFailure(t *testing.T) {
+	repo := &fakeOutboundRepo{}
+	mx := &fakeMXResolver{hosts: []string{"127.0.0.1:9999"}} // unreachable port -> connection error
+	blob := &fakeBlobReader{payload: []byte("From: a\r\nTo: b\r\n\r\nTest")}
+
+	mbID := uuid.New()
+	job := &entity.OutboundJob{
+		ID:                uuid.New(),
+		MailboxID:         &mbID,
+		BlobID:            uuid.New(),
+		EnvelopeFrom:      "user@domain.test",
+		EnvelopeTo:        "rcpt@remote.test",
+		DestinationDomain: "remote.test",
+		Status:            entity.OutboundJobStatusQueued,
+		ExpiresAt:         time.Now().Add(5 * 24 * time.Hour),
+	}
+	repo.Enqueue(context.Background(), job)
+
+	worker := NewOutboundWorkerUseCase(repo, mx, blob, nil, nil, "mail.local")
+	processed, err := worker.ProcessBatch(context.Background(), "w1", 10)
+	if err != nil || processed != 1 {
+		t.Fatalf("ProcessBatch failed: processed=%d, err=%v", processed, err)
+	}
+
+	if repo.jobs[0].Status != entity.OutboundJobStatusDeferred {
+		t.Errorf("expected DEFERRED status, got %s", repo.jobs[0].Status)
+	}
+	if repo.jobs[0].Attempt != 1 {
+		t.Errorf("attempt count = %d, want 1", repo.jobs[0].Attempt)
+	}
+	if !strings.Contains(repo.jobs[0].LastError, "dial tcp") {
+		t.Errorf("unexpected error message: %s", repo.jobs[0].LastError)
+	}
+}