Move CurrencyConverter mocking to the base test class

This mock was already applied to all tests, because it was done statically
in the TestCurrencyConverter class definition.  But it was really not
clear that it's applied everywhere.

Moving this to the setUp() function makes it much clearer.

Also, remove useless redefinition in other tests.

ihatemoney/tests/budget_test.py

@@ -4,7 +4,6 @@ import json
 import re
 from time import sleep
 import unittest
-from unittest.mock import MagicMock
 
 from flask import session
 import pytest
@@ -1464,10 +1463,6 @@ class BudgetTestCase(IhatemoneyTestCase):
 
     def test_currency_switch(self):
 
-        mock_data = {"USD": 1, "EUR": 0.8, "CAD": 1.2, CurrencyConverter.no_currency: 1}
-        converter = CurrencyConverter()
-        converter.get_rates = MagicMock(return_value=mock_data)
-
         # A project should be editable
         self.post_project("raclette")
 
@@ -1559,14 +1554,16 @@ class BudgetTestCase(IhatemoneyTestCase):
             },
         )
         last_bill = project.get_bills().first()
-        expected_amount = converter.exchange_currency(last_bill.amount, "CAD", "EUR")
+        expected_amount = self.converter.exchange_currency(
+            last_bill.amount, "CAD", "EUR"
+        )
         assert last_bill.converted_amount == expected_amount
 
         # Switch to USD. Now, NO bill should be in USD, since they already had a currency
         project.switch_currency("USD")
         for bill in project.get_bills():
             assert bill.original_currency != "USD"
-            expected_amount = converter.exchange_currency(
+            expected_amount = self.converter.exchange_currency(
                 bill.amount, bill.original_currency, "USD"
             )
             assert bill.converted_amount == expected_amount
@@ -1583,7 +1580,7 @@ class BudgetTestCase(IhatemoneyTestCase):
                 "password": "demo",
                 "contact_email": "demo@notmyidea.org",
                 "project_history": "y",
-                "default_currency": converter.no_currency,
+                "default_currency": CurrencyConverter.no_currency,
             },
         )
         # A user displayed error should be generated, and its currency should be the same.
@@ -1593,10 +1590,6 @@ class BudgetTestCase(IhatemoneyTestCase):
 
     def test_currency_switch_to_bill_currency(self):
 
-        mock_data = {"USD": 1, "EUR": 0.8, "CAD": 1.2, CurrencyConverter.no_currency: 1}
-        converter = CurrencyConverter()
-        converter.get_rates = MagicMock(return_value=mock_data)
-
         # Default currency is 'XXX', but we should start from a project with a currency
         self.post_project("raclette", default_currency="USD")
 
@@ -1620,7 +1613,7 @@ class BudgetTestCase(IhatemoneyTestCase):
         project = models.Project.query.get("raclette")
 
         bill = project.get_bills().first()
-        assert bill.converted_amount == converter.exchange_currency(
+        assert bill.converted_amount == self.converter.exchange_currency(
             bill.amount, "EUR", "USD"
         )
 
@@ -1631,10 +1624,6 @@ class BudgetTestCase(IhatemoneyTestCase):
 
     def test_currency_switch_to_no_currency(self):
 
-        mock_data = {"USD": 1, "EUR": 0.8, "CAD": 1.2, CurrencyConverter.no_currency: 1}
-        converter = CurrencyConverter()
-        converter.get_rates = MagicMock(return_value=mock_data)
-
         # Default currency is 'XXX', but we should start from a project with a currency
         self.post_project("raclette", default_currency="USD")
 
@@ -1670,12 +1659,12 @@ class BudgetTestCase(IhatemoneyTestCase):
         project = models.Project.query.get("raclette")
 
         for bill in project.get_bills_unordered():
-            assert bill.converted_amount == converter.exchange_currency(
+            assert bill.converted_amount == self.converter.exchange_currency(
                 bill.amount, "EUR", "USD"
             )
 
         # And switch project to no currency: amount should be equal to what was submitted
-        project.switch_currency(converter.no_currency)
+        project.switch_currency(CurrencyConverter.no_currency)
         no_currency_bills = [
             (bill.amount, bill.converted_amount) for bill in project.get_bills()
         ]

ihatemoney/tests/common/ihatemoney_testcase.py

@@ -1,9 +1,11 @@
 import os
+from unittest.mock import MagicMock
 
 from flask_testing import TestCase
 from werkzeug.security import generate_password_hash
 
 from ihatemoney import models
+from ihatemoney.currency_convertor import CurrencyConverter
 from ihatemoney.run import create_app, db
 
 
@@ -20,6 +22,12 @@ class BaseTestCase(TestCase):
 
     def setUp(self):
         db.create_all()
+        # Add dummy data to CurrencyConverter for all tests (since it's a singleton)
+        mock_data = {"USD": 1, "EUR": 0.8, "CAD": 1.2, CurrencyConverter.no_currency: 1}
+        converter = CurrencyConverter()
+        converter.get_rates = MagicMock(return_value=mock_data)
+        # Also add it to an attribute to make tests clearer
+        self.converter = converter
 
     def tearDown(self):
         # clean after testing