diff --git a/src/utils/scavenger.test.ts b/src/utils/scavenger.test.ts
index a557c5b1..9d768999 100644
--- a/src/utils/scavenger.test.ts
+++ b/src/utils/scavenger.test.ts
@@ -36,6 +36,8 @@ Deno.test('store one zap receipt in nostr_events; convert it into event_zaps tab
 
   // deno-lint-ignore require-await
   await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely });
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely }); // just to trigger "Error: FOREIGN KEY constraint failed"
 
   const zapReceipts = await kysely.selectFrom('nostr_events').selectAll().execute();
   const customEventZaps = await kysely.selectFrom('event_zaps').selectAll().execute();
@@ -53,3 +55,87 @@ Deno.test('store one zap receipt in nostr_events; convert it into event_zaps tab
 
   assertEquals(customEventZaps[0], expected);
 });
+
+// The function tests below only handle the edge cases and don't assert anything
+// If no error happens = ok
+
+Deno.test('savedEvent is undefined', async () => {
+  await using db = await getTestDB();
+  const kysely = db.kysely;
+
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => undefined)(), kysely: kysely });
+
+  // no error happened = ok
+});
+
+Deno.test('zap receipt does not have a "description" tag', async () => {
+  await using db = await getTestDB();
+  const kysely = db.kysely;
+
+  const sk = generateSecretKey();
+
+  const event = genEvent({ kind: 9735 }, sk);
+
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely });
+
+  // no error happened = ok
+});
+
+Deno.test('zap receipt does not have a zap request stringified value in the "description" tag', async () => {
+  await using db = await getTestDB();
+  const kysely = db.kysely;
+
+  const sk = generateSecretKey();
+
+  const event = genEvent({ kind: 9735, tags: [['description', 'yolo']] }, sk);
+
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely });
+
+  // no error happened = ok
+});
+
+Deno.test('zap receipt does not have a "bolt11" tag', async () => {
+  await using db = await getTestDB();
+  const kysely = db.kysely;
+
+  const sk = generateSecretKey();
+
+  const event = genEvent({
+    kind: 9735,
+    tags: [[
+      'description',
+      '{"pubkey":"97c70a44366a6535c145b333f973ea86dfdc2d7a99da618c40c64705ad98e322","content":"","id":"d9cc14d50fcb8c27539aacf776882942c1a11ea4472f8cdec1dea82fab66279d","created_at":1674164539,"sig":"77127f636577e9029276be060332ea565deaf89ff215a494ccff16ae3f757065e2bc59b2e8c113dd407917a010b3abd36c8d7ad84c0e3ab7dab3a0b0caa9835d","kind":9734,"tags":[["e","3624762a1274dd9636e0c552b53086d70bc88c165bc4dc0f9e836a1eaf86c3b8"],["p","32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"],["relays","wss://relay.damus.io","wss://nostr-relay.wlvs.space","wss://nostr.fmt.wiz.biz","wss://relay.nostr.bg","wss://nostr.oxtr.dev","wss://nostr.v0l.io","wss://brb.io","wss://nostr.bitcoiner.social","ws://monad.jb55.com:8080","wss://relay.snort.social"]]}',
+    ]],
+  }, sk);
+
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely });
+
+  // no error happened = ok
+});
+
+Deno.test('zap request inside zap receipt does not have an "e" tag', async () => {
+  await using db = await getTestDB();
+  const kysely = db.kysely;
+
+  const sk = generateSecretKey();
+
+  const event = genEvent({
+    kind: 9735,
+    tags: [[
+      'bolt11',
+      'lnbc10u1p3unwfusp5t9r3yymhpfqculx78u027lxspgxcr2n2987mx2j55nnfs95nxnzqpp5jmrh92pfld78spqs78v9euf2385t83uvpwk9ldrlvf6ch7tpascqhp5zvkrmemgth3tufcvflmzjzfvjt023nazlhljz2n9hattj4f8jq8qxqyjw5qcqpjrzjqtc4fc44feggv7065fqe5m4ytjarg3repr5j9el35xhmtfexc42yczarjuqqfzqqqqqqqqlgqqqqqqgq9q9qxpqysgq079nkq507a5tw7xgttmj4u990j7wfggtrasah5gd4ywfr2pjcn29383tphp4t48gquelz9z78p4cq7ml3nrrphw5w6eckhjwmhezhnqpy6gyf0',
+    ], [
+      'description',
+      '{"pubkey":"97c70a44366a6535c145b333f973ea86dfdc2d7a99da618c40c64705ad98e322","content":"","id":"d9cc14d50fcb8c27539aacf776882942c1a11ea4472f8cdec1dea82fab66279d","created_at":1674164539,"sig":"77127f636577e9029276be060332ea565deaf89ff215a494ccff16ae3f757065e2bc59b2e8c113dd407917a010b3abd36c8d7ad84c0e3ab7dab3a0b0caa9835d","kind":9734,"tags":[["p","32e1827635450ebb3c5a7d12c1f8e7b2b514439ac10a67eef3d9fd9c5c68e245"],["relays","wss://relay.damus.io","wss://nostr-relay.wlvs.space","wss://nostr.fmt.wiz.biz","wss://relay.nostr.bg","wss://nostr.oxtr.dev","wss://nostr.v0l.io","wss://brb.io","wss://nostr.bitcoiner.social","ws://monad.jb55.com:8080","wss://relay.snort.social"]]}',
+    ]],
+  }, sk);
+
+  // deno-lint-ignore require-await
+  await scavengerEvent({ savedEvent: (async () => event)(), kysely: kysely });
+
+  // no error happened = ok
+});