Task 1.1: Automated tests

app_python/Dockerfile

@@ -3,7 +3,7 @@ FROM python:3.10.13-alpine3.19
 WORKDIR /app
 EXPOSE 5000
 RUN ["adduser", "-Ds", "/usr/bin/nologin", "flask"]
-COPY requirements.txt *.py /app/
+COPY requirements.txt moscow_time/*.py /app/
 # Note: keeping the project files owned by root so
 # the web server has less privileges over them
 USER flask:flask

app_python/PYTHON.md

@@ -24,3 +24,27 @@ deployed in a rather advanced way.
     be set to one other than Moscow) or local time (as it may be
     arbitrary), instead, it uses an external service as the source of
     truth.
+
+## Tests
+
+For the project there are unit tests that cover key functionalities
+of the web application. Tests ensure that:
+
+-   When index is queried, time is displayed. In particular, it is
+    tested that in a response a second later time advances, but no
+    more than by 2 seconds.
+
+-   Quering a URL other than index results in a 404 Not Found
+    response.
+
+-   Requests on index with method other than GET result in a
+    405 Method Not Allowed response.
+
+Tests are implemented using best practices:
+
+-   A conventional project structure splitting source code and tests.
+
+-   Web app tests are implemented in accordance with suggestions from
+    the framework's documentation.
+
+-   Tests cover behavior on both valid and errornous input.

app_python/README.md

@@ -51,3 +51,11 @@ docker run --rm -d -p 5000 kolay0ne/app_py
 ```
 
 Replace `kolay0ne/app_py` with your image/tag name if you built it manually.
+
+## Unit Tests
+
+To run unit tests:
+
+-   Install `pytest` via `pip` or using your distribution-specific method
+
+-   Go to the project directory and run the `pytest` command

app_python/main.py → app_python/moscow_time/main.py

@@ -3,7 +3,7 @@
 from flask import Flask
 import requests
 
-from cache import cache_for
+from .cache import cache_for
 
 
 app = Flask(__name__)

app_python/tests/test_web_app.py

@@ -0,0 +1,47 @@
+import re
+from datetime import timedelta
+from time import sleep
+
+from pytest import fixture
+
+from moscow_time.main import app
+
+
+app.config.update({
+    "TESTING": True,
+})
+client = app.test_client()
+
+
+def hms(hours: int, minutes: int, seconds: int) -> timedelta:
+    return timedelta(hours=hours, minutes=minutes, seconds=seconds)
+
+
+def test_get_index():
+    resp1 = client.get('/')
+    sleep(1)
+    resp2 = client.get('/')
+
+    assert resp1.status_code == 200
+    assert resp2.status_code == 200
+
+    pattern = re.compile(br'(\d{1,2}):(\d{1,2}):(\d{1,2})')
+
+    data1 = pattern.search(resp1.data)
+    data2 = pattern.search(resp2.data)
+    assert data1, "Time is in the response"
+    assert data2, "Time is in the second response"
+
+    time1 = hms(*map(int, data1.groups()))
+    time2 = hms(*map(int, data2.groups()))
+
+    # Time difference is positive but no more than 2 seconds
+    assert timedelta(0) < time2 - time1 <= timedelta(seconds=2)
+
+def test_wrong_url():
+    resp = client.get('/arbitrary/url')
+    assert resp.status_code == 404
+
+def test_post_index():
+    resp = client.post('/')
+    assert resp.status_code == 405