Paul de Raaij
d345e522bd
- Create Value[T] (frozen dataclass + ABC + Generic) in domain/framework/ - Migrate ClassifiedAdTitle and ClassifiedAdText to inherit Value[str] - Standardize all value access via .value instead of type-specific fields
46 lines
1.7 KiB
Markdown
46 lines
1.7 KiB
Markdown
# Plan: Value Object Base Class
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## Goal
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Create a generic `Value[T]` base class in the framework layer. All value objects standardize on `.value` access via inheritance.
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## Design
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### `Value[T]` base class (`domain/framework/value.py`)
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```python
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@dataclass(frozen=True)
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class Value(ABC, Generic[T]):
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value: T
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```
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- Frozen dataclass → immutability + structural equality (core Value Object semantics)
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- `Generic[T]` → type-safe `.value` access in subclasses (e.g., `Value[str]`)
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- `ABC` → mirrors the `Entity` pattern
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### Subclasses
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- `ClassifiedAdTitle(Value[str])` — drops `title: str`, inherits `value: T` bound to `str`
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- `ClassifiedAdText(Value[str])` — drops `text: str`, inherits `value: T` bound to `str`
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### Ripple effects
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Every `.title` / `.text` reference on these objects becomes `.value`:
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- `classified_ad.py` — `self.title.title` → `self.title.value`, construction calls, method bodies
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- Tests — assertions, constructions, equality checks
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## Files changed
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| File | Change |
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|------|--------|
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| `domain/framework/value.py` | New — `Value[T]` base class |
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| `domain/framework/__init__.py` | Add `Value` re-export |
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| `domain/marketplace/classified_ad_title.py` | Inherit `Value[str]`, rename field |
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| `domain/marketplace/classified_ad_text.py` | Inherit `Value[str]`, rename field |
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| `domain/marketplace/classified_ad.py` | Update `.title`/`.text` refs → `.value` |
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| `tests/test_classified_ad_title.py` | Update refs |
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| `tests/test_classified_ad_text.py` | Update refs |
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| `tests/test_classified_ad.py` | Update refs |
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## Not in scope
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`ClassifiedAdId`, `UserId`, `Money`, `Price` — stay as-is.
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## Verification
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- `pytest tests/` — all 63 tests pass
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- `ruff check .` && `ruff format --check .` — clean
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