#18: implement SMTP Submission (587/465), SASL PLAIN/LOGIN auth and preflight diagnostics

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

@@ -0,0 +1,179 @@
+package usecase
+
+import (
+	"context"
+	"strings"
+	"testing"
+
+	"lambdamail/protocols/internal/domain/entity"
+)
+
+func conflictTestInput() SyncDnsRecordsInput {
+	return SyncDnsRecordsInput{
+		DomainName:    "example.test",
+		MailHost:      "mail.example.test",
+		ServerIPv4:    "192.0.2.1",
+		RsaDkimPubKey: "rsaKey",
+		EdDkimPubKey:  "edKey",
+	}
+}
+
+// PLAN.md section 7.5: pre-existing records that are not ours are never
+// touched, only reported as conflicts. A third-party verification TXT sits at
+// the zone apex under the same type and name as our SPF record, so a reconciler
+// keyed only on type+name would overwrite it and break the other service.
+func TestSyncDnsRecords_ForeignApexTxtIsPreserved(t *testing.T) {
+	dns := newFakeDnsProvider()
+	dns.seed(entity.DnsRecord{
+		Type:  "TXT",
+		Name:  "example.test",
+		Value: "google-site-verification=abc123",
+	})
+
+	uc := NewSyncDnsRecordsUseCase(dns, nil)
+	out, err := uc.Execute(context.Background(), conflictTestInput())
+	if err != nil {
+		t.Fatalf("Execute: %v", err)
+	}
+
+	apexTxt := dns.find("TXT", "example.test")
+	if len(apexTxt) != 2 {
+		t.Fatalf("expected the foreign TXT and our SPF to coexist, got %d records", len(apexTxt))
+	}
+
+	var foundForeign, foundSPF bool
+	for _, r := range apexTxt {
+		if r.Value == "google-site-verification=abc123" {
+			foundForeign = true
+		}
+		if strings.HasPrefix(r.Value, "v=spf1") {
+			foundSPF = true
+		}
+	}
+	if !foundForeign {
+		t.Error("the foreign verification TXT was destroyed")
+	}
+	if !foundSPF {
+		t.Error("the SPF record was not created alongside the foreign apex TXT")
+	}
+	if out.ConflictCount != 0 {
+		t.Errorf("a coexisting foreign TXT is not a conflict, got ConflictCount=%d", out.ConflictCount)
+	}
+}
+
+// A name that admits only one value (the mail host A record) already pointing
+// somewhere else is a genuine conflict: silently repointing it could take down
+// an unrelated service.
+func TestSyncDnsRecords_ForeignARecordIsReportedAsConflict(t *testing.T) {
+	dns := newFakeDnsProvider()
+	dns.seed(entity.DnsRecord{
+		Type:    "A",
+		Name:    "mail.example.test",
+		Value:   "198.51.100.9",
+		Comment: "managed by something else",
+	})
+
+	uc := NewSyncDnsRecordsUseCase(dns, nil)
+	out, err := uc.Execute(context.Background(), conflictTestInput())
+	if err != nil {
+		t.Fatalf("Execute: %v", err)
+	}
+
+	records := dns.find("A", "mail.example.test")
+	if len(records) != 1 || records[0].Value != "198.51.100.9" {
+		t.Errorf("foreign A record was not left untouched: %+v", records)
+	}
+	if out.ConflictCount != 1 {
+		t.Fatalf("ConflictCount = %d, want 1", out.ConflictCount)
+	}
+	if out.Status != SyncStatusPartial {
+		t.Errorf("Status = %s, want %s", out.Status, SyncStatusPartial)
+	}
+	if !strings.Contains(out.Conflicts[0].String(), "198.51.100.9") {
+		t.Errorf("conflict report does not name the blocking value: %s", out.Conflicts[0])
+	}
+}
+
+// Our own records must still be updated in place when they drift.
+func TestSyncDnsRecords_OwnRecordDriftIsCorrected(t *testing.T) {
+	dns := newFakeDnsProvider()
+	uc := NewSyncDnsRecordsUseCase(dns, nil)
+	ctx := context.Background()
+
+	if _, err := uc.Execute(ctx, conflictTestInput()); err != nil {
+		t.Fatalf("initial Execute: %v", err)
+	}
+
+	for i, r := range dns.records {
+		if r.Type == "A" && r.Name == "mail.example.test" {
+			dns.records[i].Value = "203.0.113.7"
+		}
+	}
+
+	out, err := uc.Execute(ctx, conflictTestInput())
+	if err != nil {
+		t.Fatalf("second Execute: %v", err)
+	}
+
+	if out.UpdatedCount != 1 || out.ConflictCount != 0 {
+		t.Errorf("updated=%d conflicts=%d, want updated=1 conflicts=0", out.UpdatedCount, out.ConflictCount)
+	}
+	if records := dns.find("A", "mail.example.test"); records[0].Value != "192.0.2.1" {
+		t.Errorf("drifted A record was not corrected: got %q", records[0].Value)
+	}
+	if out.Status != SyncStatusVerified {
+		t.Errorf("Status = %s, want %s", out.Status, SyncStatusVerified)
+	}
+}
+
+type stubDnsVerifier struct {
+	invisible map[string]bool
+}
+
+func (s stubDnsVerifier) VerifyRecord(_ context.Context, record entity.DnsRecord) (bool, string) {
+	if s.invisible[record.Name] {
+		return false, "no answer"
+	}
+	return true, ""
+}
+
+// PLAN.md section 7.5 verifies through public resolvers after writing. A
+// record the provider accepted but nobody can resolve is drift, not success.
+func TestSyncDnsRecords_UnresolvableRecordIsReportedAsDrift(t *testing.T) {
+	dns := newFakeDnsProvider()
+	uc := NewSyncDnsRecordsUseCase(dns, nil)
+	uc.SetVerifier(stubDnsVerifier{invisible: map[string]bool{"mail.example.test": true}})
+
+	out, err := uc.Execute(context.Background(), conflictTestInput())
+	if err != nil {
+		t.Fatalf("Execute: %v", err)
+	}
+
+	if out.Status != SyncStatusDrift {
+		t.Errorf("Status = %s, want DRIFT", out.Status)
+	}
+	if len(out.Unverified) == 0 {
+		t.Fatal("the unresolvable record was not reported")
+	}
+	if !strings.Contains(out.Unverified[0], "mail.example.test") {
+		t.Errorf("Unverified = %v, want it to name the record", out.Unverified)
+	}
+}
+
+func TestSyncDnsRecords_AllRecordsVisibleIsVerified(t *testing.T) {
+	dns := newFakeDnsProvider()
+	uc := NewSyncDnsRecordsUseCase(dns, nil)
+	uc.SetVerifier(stubDnsVerifier{})
+
+	out, err := uc.Execute(context.Background(), conflictTestInput())
+	if err != nil {
+		t.Fatalf("Execute: %v", err)
+	}
+
+	if out.Status != SyncStatusVerified {
+		t.Errorf("Status = %s, want VERIFIED", out.Status)
+	}
+	if len(out.Unverified) != 0 {
+		t.Errorf("Unverified = %v, want empty", out.Unverified)
+	}
+}