Merge pull request 'Port cron-minutely fixes: reactivate tombstoned subs + confirm-email rate limit' (#29) from mailship-fc-merge-cron-fixes-df6 into main

Reviewed-on: #29
Reviewed-by: matt <matt@lorentz.is>

src/actions.ts

@@ -19,6 +19,11 @@ export type RegisterSubscriptionParams = {
   timezone?: string
 }
 
+// Floor on how often a confirmation email can be sent for the same subscription.
+// The client is expected to only PUT on an explicit save (GET-first on boot),
+// but a retry loop or refresh storm shouldn't be able to spam an inbox either.
+export const CONFIRM_EMAIL_COOLDOWN_SECONDS = 10 * 60
+
 export const registerSubscription = instrument(
   'actions.registerSubscription',
   async ({ pubkey, email, frequency, hour, minute, dayOfWeek, timezone }: RegisterSubscriptionParams) => {
@@ -26,8 +31,18 @@ export const registerSubscription = instrument(
     const callback = `${process.env.BASE_URL}/notify/${sub.id}`
 
     if (!sub.confirmed_at) {
-      // New or email-changed subscription — send a confirmation email.
-      await mailer.sendConfirm(sub)
+      // New or email-changed subscription — send a confirmation email, but never
+      // more than once per cooldown window. The email-change path resets
+      // last_confirm_sent_at, so a genuinely new address always gets an email
+      // right away; this only throttles repeated sends of the same address.
+      const lastSent = sub.last_confirm_sent_at
+      const cooldownElapsed =
+        !lastSent || Math.floor(Date.now() / 1000) - lastSent >= CONFIRM_EMAIL_COOLDOWN_SECONDS
+
+      if (cooldownElapsed) {
+        await mailer.sendConfirm(sub)
+        await db.markConfirmSent(sub.id)
+      }
     } else {
       // Already confirmed (e.g. frequency-only change) — reschedule the
       // cron job so it uses the new cadence immediately.

src/alert.ts

@@ -12,6 +12,7 @@ export type Subscription = {
   confirmed_at?: number
   unsubscribed_at?: number
   last_digest_at?: number
+  last_confirm_sent_at?: number
 }
 
 export const getSubscriptionError = (sub: Subscription) => {

src/database.ts

@@ -65,7 +65,8 @@ export const migrate = () =>
             created_at INTEGER NOT NULL,
             confirmed_at INTEGER,
             unsubscribed_at INTEGER,
-            last_digest_at INTEGER
+            last_digest_at INTEGER,
+            last_confirm_sent_at INTEGER
           )
         `
         )
@@ -81,6 +82,14 @@ export const migrate = () =>
           )
         `
         )
+        // Add last_confirm_sent_at for existing databases created before the
+        // confirmation-email cooldown migration.
+        const columns = await all(
+          `SELECT name FROM pragma_table_info('subscriptions')`
+        )
+        if (!columns.some((c: any) => c.name === 'last_confirm_sent_at')) {
+          await run(`ALTER TABLE subscriptions ADD COLUMN last_confirm_sent_at INTEGER`)
+        }
         await run(
           `CREATE INDEX IF NOT EXISTS idx_events_subscription_received ON events (subscription_id, received_at)`
         )
@@ -171,9 +180,11 @@ export const updateSubscription = instrument(
       )
     }
 
+    // Address changed: it's a new inbox to verify, so reset the confirm-email
+    // cooldown or the new address would inherit the old one's lockout.
     return parseSubscription(
       await get(
-        `UPDATE subscriptions SET email = ?, frequency = ?, hour = ?, minute = ?, day_of_week = ?, timezone = ?, confirmed_at = NULL, unsubscribed_at = NULL
+        `UPDATE subscriptions SET email = ?, frequency = ?, hour = ?, minute = ?, day_of_week = ?, timezone = ?, confirmed_at = NULL, unsubscribed_at = NULL, last_confirm_sent_at = NULL
          WHERE id = ? RETURNING *`,
         [email, frequency, hr, mn, dow, tz, existing.id]
       )
@@ -181,6 +192,35 @@ export const updateSubscription = instrument(
   }
 )
 
+// Record that a confirmation email was sent, for the send-cooldown.
+export const markConfirmSent = instrument(
+  'database.markConfirmSent',
+  async (id: string) => {
+    await run(`UPDATE subscriptions SET last_confirm_sent_at = ? WHERE id = ?`, [now(), id])
+  }
+)
+
+const getMostRecentTombstonedSubscription = async (pubkey: string, email: string) =>
+  parseSubscription(
+    await get(
+      `SELECT * FROM subscriptions
+       WHERE pubkey = ? AND email = ? AND unsubscribed_at IS NOT NULL
+       ORDER BY rowid DESC LIMIT 1`,
+      [pubkey, email]
+    )
+  )
+
+const reactivateSubscription = async (tombstoned: Subscription, frequency: string) =>
+  parseSubscription(
+    await get(
+      // A fresh key invalidates any previously emailed confirm link, so a new
+      // confirmation email must be allowed immediately (reset the cooldown).
+      `UPDATE subscriptions SET key = ?, frequency = ?, unsubscribed_at = NULL, last_confirm_sent_at = NULL
+       WHERE id = ? RETURNING *`,
+      [crypto.randomBytes(32).toString('hex'), frequency, tombstoned.id]
+    )
+  )
+
 export const insertSubscription = instrument(
   'database.insertSubscription',
   async (pubkey: string, email: string, frequency: string, hour?: number, minute?: number, dayOfWeek?: number, timezone?: string) => {
@@ -190,6 +230,28 @@ export const insertSubscription = instrument(
       return assertResult(await updateSubscription(existing, email, frequency, hour, minute, dayOfWeek, timezone))
     }
 
+    // No active row. If this account previously subscribed to this email and
+    // was unsubscribed, reactivate the most recent such row instead of inserting
+    // a fresh one. Otherwise every turn-on → turn-off → turn-on cycle would
+    // create a new row, abandoning the confirmed state (and the already-known key).
+    const tombstoned = await getMostRecentTombstonedSubscription(pubkey, email)
+
+    if (tombstoned) {
+      try {
+        return assertResult(await reactivateSubscription(tombstoned, frequency))
+      } catch (err: any) {
+        if (err.message?.includes('UNIQUE constraint')) {
+          const concurrent = await getSubscriptionByPubkey(pubkey)
+
+          if (concurrent) {
+            return assertResult(await updateSubscription(concurrent, email, frequency))
+          }
+        }
+
+        throw err
+      }
+    }
+
     try {
       return assertResult(
         parseSubscription(
@@ -309,6 +371,20 @@ export const getActiveSubscriptions = instrument('database.getActiveSubscription
   return rows.map(parseSubscription) as Subscription[]
 })
 
+// Every row ever created for a pubkey — both active and tombstoned. Exposed
+// primarily for tests asserting re-subscribe never grows the table.
+export const getAllSubscriptionsByPubkey = instrument(
+  'database.getAllSubscriptionsByPubkey',
+  async (pubkey: string) => {
+    const rows = await all<Row>(
+      `SELECT * FROM subscriptions WHERE pubkey = ? ORDER BY created_at`,
+      [pubkey]
+    )
+
+    return rows.map(parseSubscription) as Subscription[]
+  }
+)
+
 export const updateLastDigestAt = instrument(
   'database.updateLastDigestAt',
   async (id: string, timestamp: number) => {

test/confirm-code-on-email-change.test.ts

@@ -0,0 +1,109 @@
+import { describe, it, expect, beforeAll, afterAll, vi } from 'vitest'
+import * as db from '../src/database.js'
+import { registerSubscription } from '../src/actions.js'
+import * as mailer from '../src/mailer.js'
+
+// Regression guards for the row-reactivation fix (src/database.ts):
+//   * same-email re-subscribe → reactivates the SAME row and must NOT email a
+//     stale confirmation code to an unrelated address
+//   * new-email re-subscribe → MUST create a fresh row (fresh key) so the
+//     confirmation email carries a code bound to the new address
+//
+// We mock the mailer so these run hermetically (the unit env's SMTP is a dummy).
+
+vi.mock('../src/mailer.js', async (importOriginal) => {
+  const actual: any = await importOriginal()
+  return { ...actual, sendConfirm: vi.fn(async () => {}) }
+})
+
+const pubkey = 'new-email-' + Date.now() + '-' + Math.random().toString(36).slice(2)
+const oldEmail = `${pubkey}-old@example.com`
+const newEmail = `${pubkey}-new@example.com`
+let subscribedIds: string[] = []
+
+const subscribeIdsFor = async () => {
+  const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+  subscribedIds = rows.map((r: any) => r.id)
+  return rows
+}
+
+describe('Re-subscribe with a NEW email dispatches the correct confirmation code', () => {
+  beforeAll(async () => {
+    await db.migrate()
+    vi.mocked(mailer.sendConfirm).mockClear()
+  })
+
+  afterAll(async () => {
+    const key = (await db.getAllSubscriptionsByPubkey(pubkey))[0]?.key
+    if (key) await db.unsubscribeSubscription(key)
+  })
+
+  it('registers + confirms the original email', async () => {
+    const result = await registerSubscription({ pubkey, email: oldEmail, frequency: 'daily' })
+    expect(result.key).toBeTruthy()
+    await db.confirmSubscription(result.key)
+    expect(vi.mocked(mailer.sendConfirm)).toHaveBeenCalledTimes(1)
+  })
+
+  it('unsubscribes (DELETE flow)', async () => {
+    const active = await db.getSubscriptionByPubkey(pubkey)
+    await db.unsubscribeSubscription(active!.key)
+    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
+  })
+
+  it('re-registering with the NEW email creates a fresh row, not a reactivation', async () => {
+    vi.mocked(mailer.sendConfirm).mockClear()
+
+    const result = await registerSubscription({ pubkey, email: newEmail, frequency: 'daily' })
+
+    // A NEW confirmation email was sent — to the NEW address, with the key
+    // returned to the caller (which the caller uses to confirm).
+    const sent = vi.mocked(mailer.sendConfirm).mock.calls[0][0]
+    expect(sent.email).toBe(newEmail)
+    expect(sent.key).toBe(result.key)
+
+    // And that key actually confirms the new-email row (not the old one).
+    const confirmed = await db.confirmSubscription(result.key)
+    expect(confirmed!.sub.email).toBe(newEmail)
+    expect(confirmed!.alreadyConfirmed).toBe(false)
+  })
+
+  it('leaves the old row and new row as distinct rows', async () => {
+    const rows = await subscribeIdsFor()
+    expect(rows).toHaveLength(2)
+    expect(new Set(subscribedIds).size).toBe(2)
+  })
+})
+
+describe('Reactivating the SAME email never emails an unrelated address', () => {
+  const k = 'same-email-' + Date.now() + '-' + Math.random().toString(36).slice(2)
+  const email = `${k}@example.com`
+
+  beforeAll(async () => {
+    vi.mocked(mailer.sendConfirm).mockClear()
+  })
+
+  afterAll(async () => {
+    const key = (await db.getAllSubscriptionsByPubkey(k))[0]?.key
+    if (key) await db.unsubscribeSubscription(key)
+  })
+
+  it('register + confirm + unsubscribe, then re-register the same email', async () => {
+    const r1 = await registerSubscription({ pubkey: k, email, frequency: 'daily' })
+    await db.confirmSubscription(r1.key)
+    const row1 = (await db.getAllSubscriptionsByPubkey(k))[0]
+    await db.unsubscribeSubscription(r1.key)
+
+    vi.mocked(mailer.sendConfirm).mockClear()
+    const r2 = await registerSubscription({ pubkey: k, email, frequency: 'daily' })
+
+    // Same row, still confirmed, but a FRESH key is issued — no new
+    // confirmation email, and old tokens for this row are invalidated.
+    const rows = await db.getAllSubscriptionsByPubkey(k)
+    expect(rows).toHaveLength(1)
+    expect(r2.key).not.toBe(r1.key)
+    expect(rows[0].id).toBe(row1.id)
+    expect(rows[0].confirmed_at).toBeTruthy()
+    expect(vi.mocked(mailer.sendConfirm)).not.toHaveBeenCalled()
+  })
+})

test/confirm-email-cooldown.test.ts

@@ -0,0 +1,101 @@
+import { describe, it, expect, beforeAll, vi, afterEach, beforeEach } from 'vitest'
+import * as db from '../src/database.js'
+import { registerSubscription, CONFIRM_EMAIL_COOLDOWN_SECONDS } from '../src/actions.js'
+import * as mailer from '../src/mailer.js'
+
+// Guard: at most one confirmation email per subscription per cooldown window,
+// no matter how many PUTs arrive (e.g. a page-refresh storm while unconfirmed).
+
+vi.mock('../src/mailer.js', async (importOriginal) => {
+  const actual: any = await importOriginal()
+  return { ...actual, sendConfirm: vi.fn(async () => {}) }
+})
+
+const unique = (label: string) => `${label}-${Date.now()}-${Math.random().toString(36).slice(2)}`
+const pubkey = unique('cooldown')
+const email = `${unique('cooldown')}@example.com`
+
+const confirmCalls = () => vi.mocked(mailer.sendConfirm).mock.calls.length
+
+describe('Confirmation email cooldown', () => {
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  beforeEach(() => {
+    vi.mocked(mailer.sendConfirm).mockClear()
+  })
+
+  it('sends a confirmation email on the first register', async () => {
+    const res = await registerSubscription({ pubkey, email, frequency: 'daily' })
+    expect(res.key).toBeTruthy()
+    expect(confirmCalls()).toBe(1)
+  })
+
+  it('does NOT re-send a confirmation email on re-register (refresh/retry storm)', async () => {
+    // Simulate several PUTs arriving in quick succession (e.g. page reloads).
+    for (let i = 0; i < 5; i++) {
+      await registerSubscription({ pubkey, email, frequency: 'daily' })
+    }
+    expect(confirmCalls()).toBe(0)
+  })
+
+  it('a new frequency (setting change) does not re-send', async () => {
+    await registerSubscription({ pubkey, email, frequency: 'weekly' })
+    expect(confirmCalls()).toBe(0)
+  })
+
+  it('changing the email address sends immediately (cooldown reset)', async () => {
+    const newEmail = `${unique('cooldown')}@example.com`
+    await registerSubscription({ pubkey, email: newEmail, frequency: 'daily' })
+    expect(confirmCalls()).toBe(1)
+  })
+
+  it('a fresh unconfirmed subscription is still throttled after confirm-sent marker', async () => {
+    // New pubkey: first PUT sends one email; immediate re-PUT is suppressed.
+    const pk2 = unique('cooldown2')
+    const em2 = `${unique('cooldown2')}@example.com`
+    await registerSubscription({ pubkey: pk2, email: em2, frequency: 'daily' })
+    await registerSubscription({ pubkey: pk2, email: em2, frequency: 'daily' })
+    expect(confirmCalls()).toBe(1)
+  })
+
+  it('cooldown window constant is 10 minutes', () => {
+    expect(CONFIRM_EMAIL_COOLDOWN_SECONDS).toBe(600)
+  })
+})
+
+describe('Cooldown reset on subscription reactivation (same email, off/on cycle)', () => {
+  const k = unique('cooldown-reactivate')
+  const e = `${unique('cooldown-reactivate')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  beforeEach(() => {
+    vi.mocked(mailer.sendConfirm).mockClear()
+  })
+
+  it('register, confirm, unsubscribe, re-register same email → fresh key emails immediately', async () => {
+    const r1 = await registerSubscription({ pubkey: k, email: e, frequency: 'daily' })
+    const active = await db.getSubscriptionByPubkey(k)
+
+    // Confirm first so reactivation is a "keep confirmed" path — but that also
+    // means no confirm email on re-register (already confirmed). Verify the row
+    // is reactivated with a fresh key, not a duplicate.
+    const confirmed = await db.confirmSubscription(active!.key)
+    expect(confirmed).toBeTruthy()
+
+    await db.unsubscribeSubscription(active!.key)
+
+    vi.mocked(mailer.sendConfirm).mockClear()
+    const r2 = await registerSubscription({ pubkey: k, email: e, frequency: 'daily' })
+
+    expect(r2.key).not.toBe(r1.key) // fresh key issued
+    expect(confirmCalls()).toBe(0) // still confirmed → no new email
+
+    const rows = await db.getAllSubscriptionsByPubkey(k)
+    expect(rows).toHaveLength(1)
+  })
+})

test/integration.sh

@@ -266,6 +266,31 @@ echo "14. Delete without auth returns 401"
 DEL_NO_AUTH=$(curl -s "$BASE_URL/subscription/$KEY" -X DELETE)
 check_field "No-auth DELETE returns 401" "$DEL_NO_AUTH" "error" "NIP-98 authorization required"
 
+# Test 15: Re-subscribe after delete reactivates the same row (no duplicate)
+# Regression: DELETE tombstones the row; re-subscribing with the SAME pubkey +
+# email must reactivate it, not insert a second row (off/on cycle previously
+# accumulated one row per cycle).
+echo ""
+echo "15. Re-subscribe after delete (de-dupe regression)"
+OLD_ID=$(sqlite3 "$DB_PATH" "SELECT id FROM subscriptions WHERE pubkey='$CLIENT_PUBKEY' AND unsubscribed_at IS NOT NULL ORDER BY created_at DESC LIMIT 1;" 2>/dev/null)
+AUTH_RE=$(nip98_auth "$BASE_URL/subscription/email" PUT '{"email":"test@example.com","frequency":"daily"}')
+RE_REG=$(curl -s "$BASE_URL/subscription/email" -X PUT -H "Content-Type: application/json" \
+  -H "Authorization: $AUTH_RE" \
+  -d '{"email":"test@example.com","frequency":"daily"}')
+NEW_ID=$(sqlite3 "$DB_PATH" "SELECT id FROM subscriptions WHERE pubkey='$CLIENT_PUBKEY' AND unsubscribed_at IS NULL LIMIT 1;" 2>/dev/null)
+if [ -n "$OLD_ID" ] && [ "$NEW_ID" = "$OLD_ID" ]; then
+  pass "Re-subscribe reactivates the same row"
+else
+  fail "Re-subscribe created a duplicate row (old=$OLD_ID, new=$NEW_ID)"
+fi
+
+TOTAL_ROWS=$(sqlite3 "$DB_PATH" "SELECT COUNT(*) FROM subscriptions WHERE pubkey='$CLIENT_PUBKEY';" 2>/dev/null)
+if [ "$TOTAL_ROWS" = "1" ]; then
+  pass "Exactly one row for this pubkey"
+else
+  fail "Expected 1 row for this pubkey, got $TOTAL_ROWS"
+fi
+
 # Summary
 echo ""
 echo "========================================="

test/resubscribe-reactivates.test.ts

@@ -0,0 +1,188 @@
+import { describe, it, expect, beforeAll } from 'vitest'
+import * as db from '../src/database.js'
+
+// Regression test for the "two rows created when turning email alerts back on" bug.
+//
+// Decoded production sequence (Sep 18 2026):
+//   13:42:05 register  → row 1 (unconfirmed), confirm email #1
+//   13:44:35 DELETE    → row 1 tombstoned (unsubscribed_at set)
+//   13:44:36 register  → OLD BUG: a brand-new row 2 was inserted, confirm email #2
+//   14:02:32 confirm   → row 2 finally confirmed
+//
+// Fix: when the same pubkey re-subscribes to the same email after being
+// unsubscribed, reactivate the tombstoned row instead of inserting a new one,
+// preserving the existing confirmed state and key.
+
+const unique = (label: string) => `${label}-${Date.now()}-${Math.random().toString(36).slice(2)}`
+
+describe('Re-subscribe after DELETE reactivates the same subscription (off/on cycle)', () => {
+  const pubkey = unique('resub')
+  const email = `${unique('resub')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  it('creates an unconfirmed subscription', async () => {
+    const sub = await db.insertSubscription(pubkey, email, 'daily')
+    expect(sub).toBeTruthy()
+    expect(sub.confirmed_at).toBeFalsy()
+    expect(sub.unsubscribed_at).toBeFalsy()
+  })
+
+  it('confirms it (user clicks the confirm link)', async () => {
+    const active = await db.getSubscriptionByPubkey(pubkey)
+    const result = await db.confirmSubscription(active!.key)
+    expect(result).toBeTruthy()
+    expect(result!.alreadyConfirmed).toBe(false)
+    expect(result!.sub.confirmed_at).toBeTruthy()
+  })
+
+  it('unsubscribes it (the flotilla DELETE path)', async () => {
+    const active = await db.getSubscriptionByPubkey(pubkey)
+    const gone = await db.unsubscribeSubscription(active!.key)
+    expect(gone).toBeTruthy()
+    expect(gone!.unsubscribed_at).toBeTruthy()
+    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
+  })
+
+  it('re-registers the SAME email — must reactivate row, NOT create a second row', async () => {
+    const resigned = await db.insertSubscription(pubkey, email, 'daily')
+
+    // Restores the very same row
+    const active = await db.getSubscriptionByPubkey(pubkey)
+    expect(active).toBeTruthy()
+    expect(active!.key).toBe(resigned.key)
+    expect(active!.unsubscribed_at).toBeFalsy()
+
+    // Confirmed state is preserved — no second confirmation email needed
+    expect(active!.confirmed_at).toBeTruthy()
+
+    // Exhaustive: there exists exactly one row total for this pubkey
+    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+    expect(rows).toHaveLength(1)
+    expect(rows[0].id).toBe(active!.id)
+  })
+})
+
+describe('Re-subscribe after DELETE before ever confirming', () => {
+  const pubkey = unique('resub-unconfirmed')
+  const email = `${unique('resub-unconfirmed')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  it('registers then unsubscribes without confirming', async () => {
+    const sub = await db.insertSubscription(pubkey, email, 'daily')
+    await db.unsubscribeSubscription(sub.key)
+    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
+  })
+
+  it('re-registers the same email — reactivates same row, still unconfirmed', async () => {
+    const resigned = await db.insertSubscription(pubkey, email, 'daily')
+    const active = await db.getSubscriptionByPubkey(pubkey)
+
+    expect(active!.key).toBe(resigned.key)
+    expect(active!.id).toBe(resigned.id)
+    expect(active!.unsubscribed_at).toBeFalsy()
+    // Was never confirmed, and re-subscribing does not skip confirmation
+    expect(active!.confirmed_at).toBeFalsy()
+
+    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+    expect(rows).toHaveLength(1)
+  })
+})
+
+describe('Re-subscribe with a DIFFERENT email after DELETE', () => {
+  const pubkey = unique('resub-2')
+  const email = `${unique('resub-2')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  it('registers, confirms, and unsubscribes', async () => {
+    const sub = await db.insertSubscription(pubkey, email, 'daily')
+    await db.confirmSubscription(sub.key)
+    await db.unsubscribeSubscription(sub.key)
+    expect(await db.getSubscriptionByPubkey(pubkey)).toBeFalsy()
+  })
+
+  it('a new email creates a new row, leaving the old one tombstoned', async () => {
+    const newEmail = `${unique('resub-2-new')}@example.com`
+    const resigned = await db.insertSubscription(pubkey, newEmail, 'daily')
+
+    expect(resigned.email).toBe(newEmail)
+    expect(resigned.confirmed_at).toBeFalsy() // new address must re-confirm
+
+    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+    expect(rows).toHaveLength(2)
+    expect(rows[0].email).toBe(email) // old, tombstoned
+    expect(rows[0].unsubscribed_at).toBeTruthy()
+    expect(rows[1].email).toBe(newEmail) // new, active
+    expect(rows[1].unsubscribed_at).toBeFalsy()
+  })
+})
+
+describe('Re-subscribe with a changed frequency reactivates and updates cadence', () => {
+  const pubkey = unique('resub-freq')
+  const email = `${unique('resub-freq')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  it('registers confirm-free, unsubscribes', async () => {
+    const sub = await db.insertSubscription(pubkey, email, 'daily')
+    await db.unsubscribeSubscription(sub.key)
+  })
+
+  it('re-registers with weekly — reactivates the same row at the new cadence', async () => {
+    const resigned = await db.insertSubscription(pubkey, email, 'weekly')
+    const active = await db.getSubscriptionByPubkey(pubkey)
+
+    expect(active!.key).toBe(resigned.key)
+    expect(active!.frequency).toBe('weekly')
+    expect(active!.unsubscribed_at).toBeFalsy()
+
+    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+    expect(rows).toHaveLength(1)
+  })
+})
+
+describe('Re-subscribe with mixed emails for one pubkey picks the right row', () => {
+  const pubkey = unique('resub-mixed')
+  const emailA = `${unique('resub-mixed-a')}@example.com`
+  const emailB = `${unique('resub-mixed-b')}@example.com`
+
+  beforeAll(async () => {
+    await db.migrate()
+  })
+
+  it('creates and tombstones two different emails, then re-subscribes email B', async () => {
+    // Email A cycle
+    const subA = await db.insertSubscription(pubkey, emailA, 'daily')
+    await db.unsubscribeSubscription(subA.key)
+
+    // Email B cycle
+    const subB = await db.insertSubscription(pubkey, emailB, 'daily')
+    const bId = subB!.id
+    await db.unsubscribeSubscription(subB.key)
+
+    // Re-subscribe with email B — must reactivate B's own row, not A's,
+    // and must not resurrect the wrong email.
+    const resigned = await db.insertSubscription(pubkey, emailB, 'daily')
+    const active = await db.getSubscriptionByPubkey(pubkey)
+
+    expect(active!.id).toBe(bId)
+    expect(active!.id).not.toBe(subA!.id)
+    expect(active!.email).toBe(emailB)
+    expect(active!.unsubscribed_at).toBeFalsy()
+
+    const rows = await db.getAllSubscriptionsByPubkey(pubkey)
+    expect(rows).toHaveLength(2)
+    expect(rows.filter(r => r.email === emailA)).toHaveLength(1)
+    expect(rows.filter(r => r.email === emailB)).toHaveLength(1)
+  })
+})