Add tests for Flask views

tests/response_util.py

@@ -0,0 +1,13 @@
+# -*- encoding: utf-8 -*-
+from xml.etree import ElementTree
+
+
+def meal_names(response):
+    """Extract meal names from OpenMensa XML.
+
+    By no means below parsing is robust or complete. Below just helps ensuring that the parser indeed returns proper XML
+    instead of arbitrary responses."""
+    root = ElementTree.fromstring(response)
+    namespace = {'om': 'http://openmensa.org/open-mensa-v2'}
+    nodes = root.findall('om:canteen/om:day/om:category/om:meal/om:name', namespace)
+    return [node.text for node in nodes]

tests/stub_api.py

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+# -*- encoding: utf-8 -*-
+import httpretty
+import os
+import pytest
+
+from stw_potsdam import canteen_api
+
+
+@pytest.fixture
+def api_offline():
+    """Disallow all network requests."""
+    httpretty.enable(allow_net_connect=False)
+    yield
+    httpretty.disable()
+    httpretty.reset()
+
+
+@pytest.fixture
+def api_online_one_shot():
+    """Allow a single API request, returning the contents of 'input.json'.
+    Subsequent API invocations will return with HTTP status code 500."""
+
+    def canned_menu(request, uri, response_headers):
+        path = os.path.join(os.path.dirname(__file__), 'resources', 'input.json')
+        with open(path) as f:
+            return 200, response_headers, f.read()
+
+    responses = [
+        httpretty.Response(body=canned_menu),
+        httpretty.Response(body='invalid', status=500),
+    ]
+
+    httpretty.register_uri(httpretty.POST,  canteen_api.URL, responses=responses)
+    httpretty.enable(allow_net_connect=False)
+    yield httpretty
+    httpretty.disable()
+    httpretty.reset()

tests/test_views.py

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+# -*- encoding: utf-8 -*-
+import pytest
+
+from response_util import meal_names
+from stw_potsdam import views
+
+# noinspection PyUnresolvedReferences
+# pytest fixtures are linked via parameter names of test methods
+from stub_api import api_offline, api_online_one_shot
+
+
+def test_health_check(client):
+    response = client.get('/health_check')
+    assert response.status_code == 200
+    assert response.data == 'OK'
+
+
+def test_index(client):
+    response = client.get('/').json
+    canteen_url = response.get('griebnitzsee', None)
+    assert canteen_url, 'Known canteen in index response'
+
+    canteen = client.get(canteen_url)
+    assert canteen.status_code == 200, 'Canteen URL is reachable'
+
+
+@pytest.mark.parametrize('url', ['/canteens/spam', '/canteens/spam/meta', '/canteens/spam/menu'])
+def test_canteen_not_found(client, url):
+    response = client.get(url)
+    assert response.status_code == 404
+    assert "Canteen 'spam' not found" in response.data
+
+
+@pytest.mark.xfail(strict=True)
+def test_canteen_menu_api_unavailable(client, api_offline):
+    _request_check_meals(client)
+
+
+def test_canteen_menu_request(client, api_online_one_shot):
+    _request_check_meals(client)
+
+
+def test_canteen_menu_cached(client, api_online_one_shot):
+    _request_check_meals(client)
+    _request_check_meals(client)
+
+
+@pytest.mark.xfail(strict=True)
+def test_canteen_menu_second_request_indeed_fails(client, api_online_one_shot):
+    _request_check_meals(client)
+    views.cache.clear()
+    _request_check_meals(client)
+
+
+def _request_check_meals(client):
+    response = client.get('/canteens/griebnitzsee/menu')
+
+    assert response.status_code == 200
+    meals = meal_names(response.data)
+    assert meals[0] == u"Gefüllter Germknödel \nmit Vanillesauce und Mohnzucker"
+
+
+@pytest.fixture
+def client():
+    views.app.config['TESTING'] = True
+    return views.app.test_client()
+
+
+@pytest.fixture(autouse=True)
+def clear_cache():
+    yield
+    views.cache.clear()