test: fix flaky regtest (#2616)

* add log for invoice success
* add internal flag
* sleeping inside the tasks to not block
* sleep was wrong decrease wait time

tests/regtest/test_real_invoice.py

@@ -80,19 +80,22 @@ async def test_create_real_invoice(client, adminkey_headers_from, inkey_headers_
     assert not payment_status["paid"]
 
     async def listen():
-        found_checking_id = False
         async for checking_id in get_funding_source().paid_invoices_stream():
             if checking_id == invoice["checking_id"]:
-                found_checking_id = True
-                return
-        assert found_checking_id
+                # wait for the backend to update the payment status
+                await asyncio.sleep(1)
+                return checking_id
 
     async def pay():
-        await asyncio.sleep(3)
+        # wait a sec to paid_invoices_stream to start listening
+        await asyncio.sleep(1)
         pay_real_invoice(invoice["payment_request"])
+        return True
+
+    checking_id, paid = await asyncio.gather(listen(), pay())
+    assert paid
+    assert checking_id == invoice["payment_hash"]
 
-    await asyncio.gather(listen(), pay())
-    await asyncio.sleep(3)
     response = await client.get(
         f'/api/v1/payments/{invoice["payment_hash"]}', headers=inkey_headers_from
     )
@@ -296,22 +299,26 @@ async def test_receive_real_invoice_set_pending_and_check_state(
     assert not payment_status["paid"]
 
     async def listen():
-        found_checking_id = False
         async for checking_id in get_funding_source().paid_invoices_stream():
             if checking_id == invoice["checking_id"]:
-                found_checking_id = True
-                return
-        assert found_checking_id
+                # wait for the backend to update the payment status
+                await asyncio.sleep(1)
+                return checking_id
 
     async def pay():
-        await asyncio.sleep(3)
+        # wait a sec to paid_invoices_stream to start listening
+        await asyncio.sleep(1)
         pay_real_invoice(invoice["payment_request"])
+        return True
+
+    checking_id, paid = await asyncio.gather(listen(), pay())
+    assert paid
+    assert checking_id == invoice["payment_hash"]
 
-    await asyncio.gather(listen(), pay())
-    await asyncio.sleep(3)
     response = await client.get(
         f'/api/v1/payments/{invoice["payment_hash"]}', headers=inkey_headers_from
     )
+    assert response.status_code < 300
     payment_status = response.json()
     assert payment_status["paid"]