feat: mail service

authsession/internal/testkit/challenge_store_test.go

@@ -69,12 +69,13 @@ func TestInMemoryChallengeStoreCompareAndSwapConflict(t *testing.T) {
 func challengeFixture() challenge.Challenge {
 	timestamp := time.Unix(20, 0).UTC()
 	return challenge.Challenge{
-		ID:            common.ChallengeID("challenge-1"),
-		Email:         common.Email("pilot@example.com"),
-		CodeHash:      []byte("hash"),
-		Status:        challenge.StatusPendingSend,
-		DeliveryState: challenge.DeliveryPending,
-		CreatedAt:     timestamp,
-		ExpiresAt:     timestamp.Add(10 * time.Minute),
+		ID:                common.ChallengeID("challenge-1"),
+		Email:             common.Email("pilot@example.com"),
+		CodeHash:          []byte("hash"),
+		PreferredLanguage: "en",
+		Status:            challenge.StatusPendingSend,
+		DeliveryState:     challenge.DeliveryPending,
+		CreatedAt:         timestamp,
+		ExpiresAt:         timestamp.Add(10 * time.Minute),
 	}
 }

authsession/internal/testkit/mail_sender.go

@@ -8,7 +8,8 @@ import (
 )
 
 // RecordingMailSender is a deterministic MailSender double that records every
-// delivery request and returns preconfigured outcomes or errors.
+// delivery request, including the auth challenge-derived idempotency key, and
+// returns preconfigured outcomes or errors.
 type RecordingMailSender struct {
 	mu sync.Mutex
 

authsession/internal/testkit/support_test.go

@@ -97,8 +97,10 @@ func TestRecordingMailSender(t *testing.T) {
 	}
 
 	result, err := sender.SendLoginCode(context.Background(), ports.SendLoginCodeInput{
-		Email: common.Email("pilot@example.com"),
-		Code:  "654321",
+		Email:          common.Email("pilot@example.com"),
+		IdempotencyKey: "challenge-1",
+		Code:           "654321",
+		Locale:         "en",
 	})
 	if err != nil {
 		require.Failf(t, "test failed", "SendLoginCode() returned error: %v", err)