Pro's solution

lottery/api.py

@@ -0,0 +1,25 @@
+import random
+from dataclasses import asdict
+
+from flask import Flask
+
+from .logic import TicketGenerator, TicketSaver
+from .ports import APIPort, FilePort, RandomPort
+
+APP = Flask(__name__)
+HOSTNAME = "https://httpbin.org/post"
+LOG_FILENAME = "ticket.log"
+MAX_TICKET_NUMBER = 1000
+
+
+@APP.route("/")
+def lottery():
+    ticket_generator = TicketGenerator(
+        random_port=RandomPort(random, MAX_TICKET_NUMBER)
+    )
+    ticket_saver = TicketSaver(
+        api_port=APIPort(host=HOSTNAME), file_port=FilePort(LOG_FILENAME)
+    )
+    ticket = ticket_generator.generate_ticket()
+    ticket_saver.save_ticket(ticket)
+    return asdict(ticket)

lottery/entities.py

@@ -0,0 +1,8 @@
+from dataclasses import dataclass, field
+from datetime import datetime
+
+
+@dataclass
+class Ticket:
+    ticket_id: int
+    creation_time: datetime = field(default_factory=datetime.now)

lottery/logic.py

@@ -0,0 +1,19 @@
+from .entities import Ticket
+
+
+class TicketGenerator:
+    def __init__(self, random_port):
+        self._random_port = random_port
+
+    def generate_ticket(self):
+        return Ticket(ticket_id=self._random_port.generate())
+
+
+class TicketSaver:
+    def __init__(self, api_port, file_port):
+        self._api_port = api_port
+        self._file_port = file_port
+
+    def save_ticket(self, ticket):
+        self._file_port.save(ticket)
+        self._api_port.send(ticket)

lottery/ports.py

@@ -0,0 +1,30 @@
+from dataclasses import asdict, astuple
+
+import requests
+
+
+class RandomPort:
+    def __init__(self, random, max_number):
+        self._random = random
+        self._max_number = max_number
+
+    def generate(self):
+        return self._random.randint(1, self._max_number)
+
+
+class FilePort:
+    def __init__(self, filename):
+        self._filename = filename
+
+    def save(self, ticket):
+        with open(self._filename, "a") as file_desc:
+            file_desc.write("{0},{1}\n".format(*astuple(ticket)))
+
+
+class APIPort:
+    def __init__(self, host):
+        self._host = host
+        self.last_response = None
+
+    def send(self, ticket):
+        self.last_response = requests.post(self._host, data=asdict(ticket))

run.sh

@@ -1 +1 @@
-env FLASK_APP=lottery.lottery flask run
+env FLASK_APP=lottery.api flask run

tests/test_logic.py

@@ -0,0 +1,36 @@
+from unittest.mock import Mock
+
+from pytest import fixture
+
+from lottery.logic import TicketGenerator, TicketSaver
+from lottery.ports import APIPort, FilePort, RandomPort
+
+
+@fixture
+def dummy_random():
+    return Mock(RandomPort, generate=Mock(return_value=527))
+
+
+@fixture
+def dummy_api():
+    return Mock(APIPort)
+
+
+@fixture
+def dummy_file():
+    return Mock(FilePort)
+
+
+def test_generate_ticket(dummy_random):
+    logic = TicketGenerator(random_port=dummy_random)
+
+    assert logic.generate_ticket().ticket_id == 527
+
+
+def test_send(dummy_api, dummy_file):
+    logic = TicketSaver(api_port=dummy_api, file_port=dummy_file)
+
+    logic.save_ticket(527)
+
+    dummy_api.send.assert_called_with(527)
+    dummy_file.save.assert_called_with(527)

tests/test_ports.py

@@ -0,0 +1,39 @@
+from datetime import datetime
+from random import Random
+from tempfile import mkstemp
+
+from pytest import mark
+
+from lottery.entities import Ticket
+from lottery.ports import APIPort, FilePort, RandomPort
+
+
+def test_random_port():
+    port = RandomPort(Random(10000), 1000)
+
+    assert port.generate() == 592
+
+
+@mark.integration
+def test_file_port():
+    __, path = mkstemp()
+    port = FilePort(path)
+
+    port.save(Ticket(ticket_id=123, creation_time=datetime(2020, 10, 11, 10, 22, 1)))
+    port.save(Ticket(ticket_id=987, creation_time=datetime(2020, 10, 11, 11, 22, 1)))
+
+    with open(path, "r") as desc:
+        assert desc.read() == "123,2020-10-11 10:22:01\n987,2020-10-11 11:22:01\n"
+
+
+@mark.integration
+def test_api_port():
+    port = APIPort("https://httpbin.org/post")
+
+    port.send(Ticket(ticket_id=123, creation_time=datetime(2020, 10, 11, 10, 22, 1)))
+
+    assert port.last_response.status_code == 200
+    assert port.last_response.json()["form"] == {
+        "creation_time": "2020-10-11 10:22:01",
+        "ticket_id": "123",
+    }