Improvement: model unit tests, from 3 of 17 models covered to all of them¶

Summary: Adds six test_models_*.py modules mirroring the models/ package, shared model factories in conftest.py built from the real tests/data/ exports, and fixes the NoReverseMatch in Post.get_absolute_url() that the new tests exposed.

📊 Before¶

src/parodynews/models/ holds 17 model classes across six modules. Only three — Thread, Message, AppConfig — were referenced by any model-level test, all of them incidentally, inside test_thread_message_delete.py. test_model_table.py's 15 tests exercise the model-table view, which is a different guarantee, and test_templates.py's 38 are template tests.

Statement coverage of src/parodynews/models/ was 85%, and base.py was at 0%.

✅ Change¶

Six test modules, mirroring the package¶

module	covers
`test_models_base.py`	`TimestampedModel`, `DisplayFieldsMixin`
`test_models_config.py`	`PoweredBy`, `AppConfig`, `FieldDefaults`
`test_models_ai.py`	`JSONSchema`, `OpenAIModel`, `Assistant`, `AssistantGroup`, `AssistantGroupMembership`
`test_models_content.py`	`ContentDetail`, `ContentItem`
`test_models_conversation.py`	`Thread`, `Message`
`test_models_publishing.py`	`PostPageConfigModel`, `Post`, `PostFrontMatter`, `PostVersion`

Each asserts field definitions and defaults, __str__, get_display_fields(), Meta.ordering, every ForeignKey/ManyToMany/OneToOne, and the on_delete behaviour of each relation — CASCADE and SET_NULL are asserted separately, because which one a relation uses is the difference between losing a published post and keeping it.

The two custom save() methods get behavioural tests rather than does-not-raise tests:

ContentItem.save() numbers items per parent detail. An implementation based on a global count() would pass a single-parent test; the added test_save_numbers_each_detail_independently fails it.
FieldDefaults.save() exists only to cache.delete("field_defaults"). It is asserted on insert, on update, and — separately — that it does not evict other keys, which is what a cache.clear() regression would do.

Shared factories, built from the real exports¶

conftest.py gains *_export fixtures that read tests/data/*.json as-is and a chain of model factories (user → openai_model → assistant → content_detail → content_item → thread → message → post). No parallel fixture mechanism and no new dependency — factory_boy was deliberately not added.

TimestampedModel is the one class in the package that is not instantiated: it is abstract = True and has no concrete subclass in the tree (OpenAIModel and Post declare their own timestamp columns), so it is asserted through its field definitions and its abstractness.

A completeness guard¶

test_every_exported_model_has_a_test_module asserts that every name in parodynews.models.__all__ is referenced by one of the six modules, so a model added later without tests fails the suite instead of passing quietly.

🐛 Defect found and fixed¶

Post.get_absolute_url() raised on every call:

# Before
return reverse("post_detail", kwargs={"pk": self.pk})
# django.urls.exceptions.NoReverseMatch: Reverse for 'post_detail' with keyword
# arguments '{'pk': 5}' not found. 1 pattern(s) tried:
# ['posts/(?P<post_id>[0-9]+)/\\Z']

# After
return reverse("post_detail", kwargs={"post_id": self.pk})

parodynews/urls.py:161 declares the route as posts/<int:post_id>/. The method was never called by a test, and this is precisely the class of defect issue #51 was filed to surface. It is a one-word fix in models/publishing.py; no migration, no signature change.

🧪 Testing and Validation¶

Run from src/ (config: src/pytest.ini, e2e excluded by default) against the project's PostgreSQL test database — base.py rejects SQLite outright:

$ python -m pytest parodynews/tests -q
56 passed, 9 deselected          # before
173 passed, 9 deselected         # after

Statement coverage of src/parodynews/models/:

module	before	after
`__init__.py`	100%	100%
`ai.py`	89%	100%
`base.py`	0%	100%
`config.py`	87%	100%
`content.py`	79%	100%
`conversation.py`	95%	100%
`publishing.py`	87%	100%
TOTAL	85%	100%

ruff check and ruff format --check pass on every added and changed file.

⚠️ Breaking Changes and Migration¶

None. No model field changed, no migration is required, and no dependency was added to pyproject.toml.

Issue: #51 (parent: #50)
Package: src/parodynews/models/README.md
Test conventions: src/parodynews/tests/README.md
Fixture exports: src/parodynews/tests/data/README.md
Route: src/parodynews/urls.py → post_detail
Django testing topics