Change get_latest_price to use None instead of current datetime, add …

…unit test

beanprice/sources/ecbrates.py

@@ -45,11 +45,12 @@ def _get_rate_EUR_to_CCY(currency, date):
     # Call API
     symbol = f"D.{currency}.EUR.SP00.A"
     params = {
-        "endPeriod": date,
         "format": "csvdata",
         "detail": "full",
         "lastNObservations": 1
         }
+    if date is not None:
+        params["endPeriod"] = date
     url = f"https://data-api.ecb.europa.eu/service/data/EXR/{symbol}"
     response = requests.get(url, params=params)
     if response.status_code != requests.codes.ok:
@@ -98,7 +99,7 @@ def _get_quote(ticker, date):
 
     # Calculate base -> symbol
     if EUR_to_symbol is None or EUR_to_base is None:
-        return None
+        raise ECBRatesError(f"At least one of the subrates returned None: (EUR{symbol}: {EUR_to_symbol}, EUR{base}: {EUR_to_base})")
     else:
         # Derive precision from sunrates (must be at least 5)
         minimal_precision = 5
@@ -111,7 +112,7 @@ def _get_quote(ticker, date):
 class Source(source.Source):
 
     def get_latest_price(self, ticker):
-        return _get_quote(ticker, now().date().isoformat())
+        return _get_quote(ticker, None)
 
     def get_historical_price(self, ticker, time):
         return _get_quote(ticker, time.date().isoformat())

beanprice/sources/ecbrates_test.py

@@ -0,0 +1,66 @@
+import unittest
+from unittest import mock
+from beanprice import source
+from beanprice.sources import ecbrates
+import requests
+from decimal import Decimal
+from datetime import datetime
+from dateutil import tz
+
+
+ECB_CSV = """KEY,FREQ,CURRENCY,CURRENCY_DENOM,EXR_TYPE,EXR_SUFFIX,TIME_PERIOD,OBS_VALUE,OBS_STATUS,OBS_CONF,OBS_PRE_BREAK,OBS_COM,TIME_FORMAT,BREAKS,COLLECTION,COMPILING_ORG,DISS_ORG,DOM_SER_IDS,PUBL_ECB,PUBL_MU,PUBL_PUBLIC,UNIT_INDEX_BASE,COMPILATION,COVERAGE,DECIMALS,NAT_TITLE,SOURCE_AGENCY,SOURCE_PUB,TITLE,TITLE_COMPL,UNIT,UNIT_MULT
+EXR.D.SEK.EUR.SP00.A,D,SEK,EUR,SP00,A,2024-12-24,11.5335,A,F,,,P1D,,A,,,,,,,,,,4,,4F0,,Euro/Swedish krona,"ECB reference exchange rate, Euro/Swedish krona, 2:15 pm (C.E.T.)",SEK,0
+"""
+
+ECB_CSV_HIST = """KEY,FREQ,CURRENCY,CURRENCY_DENOM,EXR_TYPE,EXR_SUFFIX,TIME_PERIOD,OBS_VALUE,OBS_STATUS,OBS_CONF,OBS_PRE_BREAK,OBS_COM,TIME_FORMAT,BREAKS,COLLECTION,COMPILING_ORG,DISS_ORG,DOM_SER_IDS,PUBL_ECB,PUBL_MU,PUBL_PUBLIC,UNIT_INDEX_BASE,COMPILATION,COVERAGE,DECIMALS,NAT_TITLE,SOURCE_AGENCY,SOURCE_PUB,TITLE,TITLE_COMPL,UNIT,UNIT_MULT
+EXR.D.SEK.EUR.SP00.A,D,SEK,EUR,SP00,A,2024-12-06,11.523,A,F,,,P1D,,A,,,,,,,,,,4,,4F0,,Euro/Swedish krona,"ECB reference exchange rate, Euro/Swedish krona, 2:15 pm (C.E.T.)",SEK,0
+"""
+
+
+def response(contents, status_code=requests.codes.ok):
+    """Return a context manager to patch a CSV response."""
+    response = mock.Mock()
+    response.status_code = status_code
+    response.text = contents
+    return mock.patch('requests.get', return_value=response)
+
+
+class ECBRatesErrorFetcher(unittest.TestCase):
+    def test_error_invalid_ticker(self):
+        with self.assertRaises(ValueError) as exc:
+            ecbrates.Source().get_latest_price('INVALID')
+
+    def test_error_network(self):
+        with response('Foobar', 404):
+            with self.assertRaises(ValueError) as exc:
+                ecbrates.Source().get_latest_price('EUR-SEK')
+
+    def test_empty_response(self):
+        with response('', 200):
+            with self.assertRaises(ecbrates.ECBRatesError) as exc:
+                ecbrates.Source().get_latest_price('EUR-SEK')
+
+    def test_valid_response(self):
+        contents = ECB_CSV
+        with response(contents):
+            srcprice = ecbrates.Source().get_latest_price('EUR-SEK')
+            self.assertIsInstance(srcprice, source.SourcePrice)
+            self.assertEqual(Decimal('11.5335'), srcprice.price)
+            self.assertEqual('SEK', srcprice.quote_currency)
+            self.assertIsInstance(srcprice.time, datetime)
+            self.assertEqual(datetime(2024, 12, 24, 0, 0, 0, tzinfo=tz.tzutc()), srcprice.time)
+
+
+    def test_historical_price(self):
+        time = datetime(2024, 12, 6, 16, 0, 0, tzinfo=tz.tzlocal()).astimezone(tz.tzutc())
+        contents = ECB_CSV_HIST
+        with response(contents):
+            srcprice = ecbrates.Source().get_historical_price('EUR-SEK', time)
+            self.assertIsInstance(srcprice, source.SourcePrice)
+            self.assertEqual(Decimal('11.523'), srcprice.price)
+            self.assertEqual('SEK', srcprice.quote_currency)
+            self.assertIsInstance(srcprice.time, datetime)
+            self.assertEqual(datetime(2024, 12, 6, 0, 0, 0, tzinfo=tz.tzutc()), srcprice.time)
+
+if __name__ == '__main__':
+    unittest.main()