Created the models and its test

expenses_manager/expenses/admin.py

@@ -1,3 +1,7 @@
 from django.contrib import admin
+from .models import Category, Account, Tag, Expense
 
-# Register your models here.
+admin.site.register(Category)
+admin.site.register(Account)
+admin.site.register(Tag)
+admin.site.register(Expense)

expenses_manager/expenses/migrations/0001_initial.py

@@ -0,0 +1,65 @@
+# Generated by Django 5.2.10 on 2026-01-07 22:49
+
+import django.db.models.deletion
+from django.conf import settings
+from django.db import migrations, models
+
+
+class Migration(migrations.Migration):
+
+    initial = True
+
+    dependencies = [
+        migrations.swappable_dependency(settings.AUTH_USER_MODEL),
+    ]
+
+    operations = [
+        migrations.CreateModel(
+            name='Account',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=100)),
+                ('owner', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='accounts', to=settings.AUTH_USER_MODEL)),
+            ],
+        ),
+        migrations.CreateModel(
+            name='Category',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=100)),
+                ('parent', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.CASCADE, related_name='children', to='expenses.category')),
+            ],
+            options={
+                'verbose_name_plural': 'categories',
+                'unique_together': {('name', 'parent')},
+            },
+        ),
+        migrations.CreateModel(
+            name='Tag',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('name', models.CharField(max_length=50)),
+                ('owner', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='tags', to=settings.AUTH_USER_MODEL)),
+            ],
+            options={
+                'unique_together': {('name', 'owner')},
+            },
+        ),
+        migrations.CreateModel(
+            name='Expense',
+            fields=[
+                ('id', models.BigAutoField(auto_created=True, primary_key=True, serialize=False, verbose_name='ID')),
+                ('date', models.DateField()),
+                ('amount', models.DecimalField(decimal_places=2, max_digits=10)),
+                ('description', models.TextField(blank=True)),
+                ('created_at', models.DateField(auto_now_add=True)),
+                ('account', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='expenses', to='expenses.account')),
+                ('category', models.ForeignKey(blank=True, null=True, on_delete=django.db.models.deletion.SET_NULL, related_name='expenses', to='expenses.category')),
+                ('owner', models.ForeignKey(on_delete=django.db.models.deletion.CASCADE, related_name='expenses', to=settings.AUTH_USER_MODEL)),
+                ('tags', models.ManyToManyField(blank=True, related_name='expenses', to='expenses.tag')),
+            ],
+            options={
+                'ordering': ['-date'],
+            },
+        ),
+    ]

expenses_manager/expenses/models.py

@@ -1,3 +1,89 @@
 from django.db import models
+from django.conf import settings
+from django.db.models.fields import related
 
-# Create your models here.
+class Category(models.Model):
+    name = models.CharField(max_length=100)
+    parent = models.ForeignKey(
+        "self",
+        on_delete=models.CASCADE,
+        null=True,
+        blank=True,
+        related_name="children",
+    )
+    
+    class Meta:
+        unique_together = ("name", "parent")
+        verbose_name_plural = "categories"
+    
+    def __str__(self):
+        return self.name
+
+
+class Account(models.Model):
+    name = models.CharField(max_length=100)
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="accounts",
+    )
+    
+    def __str__(self):
+        return self.name
+
+
+class Tag(models.Model):
+    name = models.CharField(max_length=50)
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="tags",
+    )
+    
+    class Meta:
+        unique_together = ("name", "owner")
+        
+    def __str__(self):
+        return self.name
+    
+
+class Expense(models.Model):
+    date = models.DateField()
+    amount = models.DecimalField(max_digits=10, decimal_places=2)
+    description = models.TextField(blank=True)
+    
+    owner = models.ForeignKey(
+        settings.AUTH_USER_MODEL,
+        on_delete=models.CASCADE,
+        related_name="expenses",
+    )
+    
+    category = models.ForeignKey(
+        Category,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="expenses",
+    )
+    
+    account = models.ForeignKey(
+        Account,
+        on_delete=models.SET_NULL,
+        null=True,
+        blank=True,
+        related_name="expenses",
+    )
+    
+    tags = models.ManyToManyField(
+        Tag,
+        blank=True,
+        related_name="expenses",
+    )
+    
+    created_at = models.DateField(auto_now_add=True)
+    
+    class Meta:
+        ordering = ["-date"]
+    
+    def __str__(self):
+        return "{} - {}".format(self.date, self.amount)

expenses_manager/expenses/tests/test_models.py

@@ -0,0 +1,26 @@
+import pytest
+from django.contrib.auth.models import User
+from expenses.models import Category, Account, Expense
+
+@pytest.mark.django_db
+def test_create_basic_expense():
+    user = User.objects.create_user(
+        username="testuser",
+        password="password",
+    )
+    
+    category = Category.objects.create(name="Comida")
+    account = Account.objects.create(name="Cuenta principal", owner=user)
+    
+    expense = Expense.objects.create(
+        date="2024-01-01",
+        amount=25.50,
+        owner=user,
+        category=category,
+        account=account
+    )
+    
+    assert expense.amount == 25.50
+    assert expense.category.name == "Comida"
+    assert expense.owner.username == "testuser"
+