ZacharyZhang-NY
e74dafcd36
Three independently ugly bugs that all fed the same log flood:
* Electron's `WebFrameMain.send` writes every "Render frame was disposed"
to stderr via `console.error`. When the worker fans a second
agent-event past a reloading renderer, we produced thousands of
identical lines and stalled the main loop on stderr I/O. Added a
`mainFrame.detached` guard so the send is short-circuited before
Electron's own catch block fires, and installed a targeted filter in
`suppress-warnings.ts` (now actually imported from the entry point)
so the specific `console.error("Error sending from webFrameMain:"…)`
noise never reaches the terminal. Any other payload still surfaces.
* `dispatchAgentMessage` accepted the human-reader sentinel as a wake
target when an agent replied to `__board__` — `wakeAgentIfPossible`
then called `db.getAgent("__board__")`, threw, and the dispatcher
kept repeating on every send. Strip `HUMAN_SENDER_ID` at
`resolveMessageWakeTargets`, and keep a defense-in-depth guard in the
heartbeat so a stray caller (future automation fan-out) cannot
reintroduce the crash.
* Pi's skills loader rejects any SKILL.md whose frontmatter `name`
diverges from its parent directory. The four bundled `my-writing-style`
copies declared `name: writing-style-skill`, so every install emitted
a warning and dropped the skill. They also lived as orphan gitlinks
(mode 160000 without .gitmodules), and the global `*.md` gitignore
hid every other SKILL.md from version control. Fixed the frontmatter
to match the dir, converted the dangling submodules to plain trees,
and allowlisted `builtin-skills/**/*.md` so a fresh clone carries the
catalogue instead of silently losing it.
84 lines
2.8 KiB
Markdown
84 lines
2.8 KiB
Markdown
---
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title: Encapsulate Business Invariants Within Entities
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impact: CRITICAL
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impactDescription: prevents invalid state, centralizes validation
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tags: entity, invariants, validation, encapsulation
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---
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## Encapsulate Business Invariants Within Entities
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Business rules that must always be true (invariants) should be enforced by the entity itself. External code should not be able to put an entity into an invalid state.
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**Incorrect (invariants scattered outside entity):**
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```python
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# application/usecases/transfer_money.py
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class TransferMoneyUseCase:
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def execute(self, from_id, to_id, amount):
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from_account = self.repo.find(from_id)
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to_account = self.repo.find(to_id)
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# Validation scattered in use case
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if from_account.balance < amount:
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raise InsufficientFundsError()
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if amount <= 0:
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raise InvalidAmountError()
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if from_account.status != 'active':
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raise AccountInactiveError()
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from_account.balance -= amount # Direct field mutation
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to_account.balance += amount
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# Another use case might forget these checks!
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```
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**Correct (invariants enforced by entity):**
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```python
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# domain/entities/account.py
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class Account:
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def __init__(self, id: AccountId, balance: Money, status: AccountStatus):
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self._id = id
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self._balance = balance
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self._status = status
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def withdraw(self, amount: Money) -> None:
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self._ensure_active()
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self._ensure_positive_amount(amount)
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self._ensure_sufficient_funds(amount)
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self._balance = self._balance.subtract(amount)
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def deposit(self, amount: Money) -> None:
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self._ensure_active()
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self._ensure_positive_amount(amount)
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self._balance = self._balance.add(amount)
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def _ensure_active(self) -> None:
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if self._status != AccountStatus.ACTIVE:
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raise AccountInactiveError(self._id)
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def _ensure_positive_amount(self, amount: Money) -> None:
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if amount.is_zero_or_negative():
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raise InvalidAmountError(amount)
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def _ensure_sufficient_funds(self, amount: Money) -> None:
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if self._balance.less_than(amount):
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raise InsufficientFundsError(self._id, self._balance, amount)
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# application/usecases/transfer_money.py
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class TransferMoneyUseCase:
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def execute(self, from_id, to_id, amount):
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from_account = self.repo.find(from_id)
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to_account = self.repo.find(to_id)
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from_account.withdraw(amount) # Invariants guaranteed
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to_account.deposit(amount)
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```
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**Benefits:**
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- Impossible to create invalid account state
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- Validation rules documented in one place
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- Every use case gets consistent validation automatically
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Reference: [Domain-Driven Design - Aggregates](https://martinfowler.com/bliki/DDD_Aggregate.html)
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