Add formatting/linting and more tests

.env.example

@@ -1,5 +1,6 @@
 DATABASE_URL=sqlite:///db.sqlite3
 EMAIL_URL=smtp+tls://user:hunter2%40%3Axyz%3F%21@localhost:587
+EMAIL_FROM_ADDRESS=sample_bar@example.com
 LANGUAGE_CODE=en-us
 TIME_ZONE=Europe/Berlin
 SECRET_KEY=GENERATE THIS! See e.g. https://humberto.io/blog/tldr-generate-django-secret-key/

.github/workflows/ci.yml

@@ -44,11 +44,16 @@ jobs:
 
       - name: Install dependencies
         run: |
-          pip3 install -r requirements.txt
+          pip3 install -r requirements.txt -r requirements-dev.txt
           cp .env.example .env
           touch db.sqlite3
           chmod 666 db.sqlite3
 
+      - name: Lint and format check
+        run: |
+          ruff format --check . || (echo "Run 'ruff format .' to fix formatting" && exit 1)
+          ruff check . || (echo "Run 'ruff check --fix .' to fix lint violations" && exit 1)
+
       - name: Run unit tests
         run: python3 manage.py test
 

README.md

@@ -123,7 +123,7 @@ In case you do not want to use the Docker installation method, e.g. because you
    # possibly: sudo apt install virtualenv
    virtualenv -p python3 .
    source bin/activate # activate virtualenv
-   pip3 install -r requirements.txt
+   pip3 install -r requirements.txt -r requirements-dev.txt
    # Create .env configuration file and generate SECRET_KEY
    cat .env.example | grep -v "SECRET_KEY" > .env
    echo SECRET_KEY=$(tr -dc 'a-z0-9!@#%^&*(-_=+)' < /dev/urandom | head -c50) >> .env
@@ -216,7 +216,7 @@ You can also look into the git log:
 ```bash
 git fetch # get information about changes but do not touch local files
 git log origin/master # show latest changes on master
-````
+```
 
 When you want to apply the update, simply pull in the changes (you should not have modified any pybarsys files):
 ```bash

barsys/apps.py

@@ -2,4 +2,4 @@
 
 
 class BarsysConfig(AppConfig):
-    name = 'barsys'
+    name = "barsys"

barsys/filters.py

@@ -4,60 +4,82 @@
 
 
 class UserFilter(django_filters.FilterSet):
-    display_name = django_filters.CharFilter(lookup_expr='icontains')
-    email = django_filters.CharFilter(lookup_expr='icontains')
-    purchases_paid_by_other = django_filters.BooleanFilter(method="filter_has_purchases_paid_by_other")
+    display_name = django_filters.CharFilter(lookup_expr="icontains")
+    email = django_filters.CharFilter(lookup_expr="icontains")
+    purchases_paid_by_other = django_filters.BooleanFilter(
+        method="filter_has_purchases_paid_by_other"
+    )
     created_date = django_filters.DateTimeFromToRangeFilter(
-        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default.")
+        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default."
+    )
 
     class Meta:
         model = User
-        fields = ['display_name', 'email', 'is_active', 'is_buyer', 'is_favorite', 'is_admin', 'is_autolocked']
+        fields = [
+            "display_name",
+            "email",
+            "is_active",
+            "is_buyer",
+            "is_favorite",
+            "is_admin",
+            "is_autolocked",
+        ]
 
     def filter_has_purchases_paid_by_other(self, queryset, name, value):
         return queryset.filter(purchases_paid_by_other__isnull=not value)
 
 
 class PurchaseFilter(django_filters.FilterSet):
-    username = django_filters.CharFilter(field_name="user__display_name", lookup_expr='icontains')
-
-    product_name = django_filters.CharFilter(lookup_expr='icontains')
-    product_amount = django_filters.CharFilter(lookup_expr='icontains')
-    product_category = django_filters.CharFilter(lookup_expr='icontains')
-    invoice = django_filters.BooleanFilter(method='filter_has_invoice', label="Invoiced")
+    username = django_filters.CharFilter(
+        field_name="user__display_name", lookup_expr="icontains"
+    )
+
+    product_name = django_filters.CharFilter(lookup_expr="icontains")
+    product_amount = django_filters.CharFilter(lookup_expr="icontains")
+    product_category = django_filters.CharFilter(lookup_expr="icontains")
+    invoice = django_filters.BooleanFilter(
+        method="filter_has_invoice", label="Invoiced"
+    )
     created_date = django_filters.DateTimeFromToRangeFilter(
-        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default.")
-    is_free_item_purchase = django_filters.BooleanFilter(help_text="Whether the purchase was done with a free item "
-                                                                   "(i.e. it was already purchased with a cost before). "
-                                                                   "If you only want to count 'real' purchases you should set "
-                                                                   "this to 'No'.")
+        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default."
+    )
+    is_free_item_purchase = django_filters.BooleanFilter(
+        help_text="Whether the purchase was done with a free item "
+        "(i.e. it was already purchased with a cost before). "
+        "If you only want to count 'real' purchases you should set "
+        "this to 'No'."
+    )
 
     def filter_has_invoice(self, queryset, name, value):
         return queryset.filter(invoice__isnull=not value)
 
     class Meta:
         model = Purchase
-        fields = ["user", "is_free_item_purchase", ]
+        fields = [
+            "user",
+            "is_free_item_purchase",
+        ]
 
 
 class ProductAutochangeSetFilter(django_filters.FilterSet):
-    title = django_filters.CharFilter(lookup_expr='icontains')
-    description = django_filters.CharFilter(lookup_expr='icontains')
+    title = django_filters.CharFilter(lookup_expr="icontains")
+    description = django_filters.CharFilter(lookup_expr="icontains")
 
     class Meta:
         model = ProductAutochangeSet
-        fields = ['title', 'description']
+        fields = ["title", "description"]
 
 
 class PaymentFilter(django_filters.FilterSet):
     payment_method = django_filters.ChoiceFilter(choices=Payment.PAYMENT_METHOD_CHOICES)
 
-    comment = django_filters.CharFilter(lookup_expr='icontains')
-    amount__gte = django_filters.NumberFilter(field_name='amount', lookup_expr='gte')
-    amount__lte = django_filters.NumberFilter(field_name='amount', lookup_expr='lte')
+    comment = django_filters.CharFilter(lookup_expr="icontains")
+    amount__gte = django_filters.NumberFilter(field_name="amount", lookup_expr="gte")
+    amount__lte = django_filters.NumberFilter(field_name="amount", lookup_expr="lte")
 
     created_date = django_filters.DateTimeFromToRangeFilter(
-        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default.")
+        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default."
+    )
 
     value_date = django_filters.DateFromToRangeFilter(help_text="Format YYYY-MM-DD.")
 
@@ -67,8 +89,10 @@ class Meta:
 
 
 class FreeItemFilter(django_filters.FilterSet):
-    comment = django_filters.CharFilter(lookup_expr='icontains')
-    leftover_quantity__gte = django_filters.NumberFilter(field_name='leftover_quantity', lookup_expr='gte')
+    comment = django_filters.CharFilter(lookup_expr="icontains")
+    leftover_quantity__gte = django_filters.NumberFilter(
+        field_name="leftover_quantity", lookup_expr="gte"
+    )
 
     class Meta:
         model = FreeItem
@@ -77,36 +101,45 @@ class Meta:
 
 class InvoiceFilter(django_filters.FilterSet):
     created_date = django_filters.DateTimeFromToRangeFilter(
-        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default.")
-    purchases__gte = django_filters.NumberFilter(field_name='amount_purchases', lookup_expr='gte', label="Purchases >=")
-    purchases__lte = django_filters.NumberFilter(field_name='amount_purchases', lookup_expr='lte', label="Purchases <=")
-
-    payments__gte = django_filters.NumberFilter(field_name='amount_payments', lookup_expr='gte', label="Payments >=")
-    payments__lte = django_filters.NumberFilter(field_name='amount_payments', lookup_expr='lte', label="Payments <=")
+        help_text="Format YYYY-MM-DD HH:MM. Time is 00:00 by default."
+    )
+    purchases__gte = django_filters.NumberFilter(
+        field_name="amount_purchases", lookup_expr="gte", label="Purchases >="
+    )
+    purchases__lte = django_filters.NumberFilter(
+        field_name="amount_purchases", lookup_expr="lte", label="Purchases <="
+    )
+
+    payments__gte = django_filters.NumberFilter(
+        field_name="amount_payments", lookup_expr="gte", label="Payments >="
+    )
+    payments__lte = django_filters.NumberFilter(
+        field_name="amount_payments", lookup_expr="lte", label="Payments <="
+    )
 
     class Meta:
         model = Invoice
         fields = ["recipient"]
 
 
 class CategoryFilter(django_filters.FilterSet):
-    name = django_filters.CharFilter(lookup_expr='icontains')
+    name = django_filters.CharFilter(lookup_expr="icontains")
 
     class Meta:
         model = Category
         fields = []
 
 
 class ProductFilter(django_filters.FilterSet):
-    name = django_filters.CharFilter(lookup_expr='icontains')
+    name = django_filters.CharFilter(lookup_expr="icontains")
 
     class Meta:
         model = Product
         fields = ["name", "category", "is_active"]
 
 
 class StatsDisplayFilter(django_filters.FilterSet):
-    title = django_filters.CharFilter(lookup_expr='icontains')
+    title = django_filters.CharFilter(lookup_expr="icontains")
 
     class Meta:
         model = StatsDisplay