Dev: better test coverage for fx rates updater (#31)

backend/db.py

@@ -64,12 +64,14 @@ class ExchangeRate(Base):
 engine = create_engine('postgresql+psycopg2://{0}:{1}@{2}:{3}/{4}'.format(DB_USER, DB_PW, DB_HOST, DB_PORT, DB_NAME))
 Session = sessionmaker(bind=engine)
 
-def truncate_offers():
+
+def truncate_all_tables():
     session = Session()
     session.execute(text("TRUNCATE aircraft_offer"))
     session.commit()
     session.close()
 
+
 def store_entity(entity):
     session = Session()
     session.add(entity)
@@ -103,6 +105,7 @@ def offer_url_exists(offer_url):
     finally:
         session.close()
 
+
 def get_exchange_rates_as_dict(session):
     all_exchange_rates = session.query(ExchangeRate).all()
     exchange_rates = dict()

backend/exchange_rates.py

@@ -11,19 +11,23 @@
 
 def fetch_exchange_rates_from_ecb():
     start_time = time.time()
-    count = 0
     response = requests.get(ECB_FX_RATES_URL).text
-    et = ET.fromstring(response)
+    count = update_exchange_rates(response)
+    logger.info("Updated %d exchange rates in %.2fs", count, (time.time() - start_time))
+
+
+def update_exchange_rates(xmlData):
+    count = 0
+    et = ET.fromstring(xmlData)
     for element in et.iter():
         curr_name = element.get('currency')
         if curr_name is None:
             continue
         curr_rate = element.get('rate')
-        logger.debug("Fetched exchange rate: {0} for currency {1}".format(str(curr_rate), str(curr_name)))
         db.update_exchange_rate(db.ExchangeRate(currency=curr_name, rate=curr_rate))
         count += 1
+    return count
 
-    logger.info("Updated %d exchange rates in %.2fs", count, (time.time() - start_time))
 
 def get_currency_code(o):
     currency_str = o
@@ -36,7 +40,8 @@ def get_currency_code(o):
         '$': 'USD',
         'US$': 'USD',
         '£': 'GBP',
-        'Fr.': 'CHF'
+        'Fr.': 'CHF',
+        'A$': 'AUD',
     }
     if currency_str in iso_code_mapping:
         return iso_code_mapping[currency_str]

backend/run_tests.sh

@@ -3,4 +3,4 @@ export PYTHONPATH=$PYTHONPATH':./'
 set -e
 
 coverage run --source ./ --omit="tests/*" -m xmlrunner -o ./test-results
-coverage report --fail-under=65
+coverage report --fail-under=70

backend/tests/eurofxref-daily.xml

@@ -0,0 +1,41 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<gesmes:Envelope xmlns:gesmes="http://www.gesmes.org/xml/2002-08-01" xmlns="http://www.ecb.int/vocabulary/2002-08-01/eurofxref">
+	<gesmes:subject>Reference rates</gesmes:subject>
+	<gesmes:Sender>
+		<gesmes:name>European Central Bank</gesmes:name>
+	</gesmes:Sender>
+	<Cube>
+		<Cube time='2024-07-02'>
+			<Cube currency='USD' rate='1.0729'/>
+			<Cube currency='JPY' rate='173.31'/>
+			<Cube currency='BGN' rate='1.9558'/>
+			<Cube currency='CZK' rate='25.185'/>
+			<Cube currency='DKK' rate='7.4590'/>
+			<Cube currency='GBP' rate='0.84755'/>
+			<Cube currency='HUF' rate='395.60'/>
+			<Cube currency='PLN' rate='4.3250'/>
+			<Cube currency='RON' rate='4.9769'/>
+			<Cube currency='SEK' rate='11.4170'/>
+			<Cube currency='CHF' rate='0.9697'/>
+			<Cube currency='ISK' rate='149.30'/>
+			<Cube currency='NOK' rate='11.4795'/>
+			<Cube currency='TRY' rate='35.0707'/>
+			<Cube currency='AUD' rate='1.6120'/>
+			<Cube currency='BRL' rate='6.0479'/>
+			<Cube currency='CAD' rate='1.4727'/>
+			<Cube currency='CNY' rate='7.8014'/>
+			<Cube currency='HKD' rate='8.3829'/>
+			<Cube currency='IDR' rate='17570.19'/>
+			<Cube currency='ILS' rate='4.0411'/>
+			<Cube currency='INR' rate='89.5417'/>
+			<Cube currency='KRW' rate='1488.26'/>
+			<Cube currency='MXN' rate='19.6825'/>
+			<Cube currency='MYR' rate='5.0630'/>
+			<Cube currency='NZD' rate='1.7693'/>
+			<Cube currency='PHP' rate='63.097'/>
+			<Cube currency='SGD' rate='1.4569'/>
+			<Cube currency='THB' rate='39.526'/>
+			<Cube currency='ZAR' rate='19.8161'/>
+		</Cube>
+	</Cube>
+</gesmes:Envelope>

backend/tests/test_db.py

@@ -8,7 +8,7 @@
 class DbTest(unittest.TestCase):
 
     def setUp(self):
-        db.truncate_offers()
+        db.truncate_all_tables()
 
     def test_should_store_and_fetch_offer(self):
         # given

backend/tests/test_exchange_rates.py

@@ -1,11 +1,33 @@
 import unittest
+from ddt import ddt
 from price_parser import Price
-from exchange_rates import get_currency_code
+from decimal import Decimal
 
+import tests.test__testcontainers_setup
+import db
+import exchange_rates
 
+@ddt
 class ExchangeRatesTest(unittest.TestCase):
 
     def test_get_currency_code(self):
-        self.assertEqual("EUR", get_currency_code(Price.fromstring("12.000,00 €")))
-        self.assertEqual("GBP", get_currency_code(Price.fromstring("16,23 £")))
-        self.assertEqual("CHF", get_currency_code(Price.fromstring("12 SFr.")))
+        self.assertEqual("EUR", exchange_rates.get_currency_code(Price.fromstring("12.000,00 €")))
+        self.assertEqual("GBP", exchange_rates.get_currency_code(Price.fromstring("16,23 £")))
+        self.assertEqual("CHF", exchange_rates.get_currency_code(Price.fromstring("12 SFr.")))
+        self.assertEqual("AUD", exchange_rates.get_currency_code(Price.fromstring("12 A$")))
+
+    def test_should_update_fx_rates_in_db(self):
+        # given
+        PRECISION = Decimal(10) ** -4
+
+        # when
+        exchange_rates.update_exchange_rates(readFile("tests/eurofxref-daily.xml"))
+
+        # then
+        fxRates = db.get_exchange_rates_as_dict(db.Session())
+        self.assertEqual(fxRates["PLN"].quantize(PRECISION), Decimal(4.3250).quantize(PRECISION))
+
+
+def readFile(name: str):
+    with open(name, 'r') as file:
+        return file.read()

backend/tests/test_pipelines.py

@@ -13,7 +13,7 @@
 class DuplicateDetectionTest(unittest.TestCase):
 
     def setUp(self):
-        db.truncate_offers()
+        db.truncate_all_tables()
 
         self.sample_offer = buildOfferWithUrl("https://offers.com/1")
         self.detection = pipelines.DuplicateDetection()
@@ -111,7 +111,7 @@ def test_regular_offers_are_not_dropped(self, offer_title):
 class StoragePipelineTest(unittest.TestCase):
 
     def setUp(self):
-        db.truncate_offers()
+        db.truncate_all_tables()
         self.storage = pipelines.StoragePipeline()
 
     def test_should_store_offer(self):