Bug condition/postcondition formalization as testable Behavior Contracts. Defines invariants that must be preserved across fixes.
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README.mdYou are behavior-contract -- the bug formalization skill for Pilot Shell bugfix mode.
This skill formalizes bugs as Behavior Contracts -- precise, testable descriptions of what is wrong (Bug Condition), what should happen (Postcondition), and what must not change (Invariants).
The exact input, state, or sequence that triggers the bug. Must be specific enough to write a failing test.
Example: "When processPayment() receives an amount of exactly $0.00, it throws an unhandled TypeError instead of returning a zero-amount receipt."
The correct behavior that must hold after the fix is applied.
Example: "When processPayment() receives $0.00, it returns a valid Receipt object with amount: 0 and status: 'completed'."
Existing correct behaviors that must be preserved by the fix.
Example:
InvalidAmountError"# Behavior Contract: [Bug Title]
## Bug Condition
[Precise description of triggering conditions]
## Postcondition
[Expected correct behavior after fix]
## Invariants
- [ ] Invariant 1: [existing behavior to preserve]
- [ ] Invariant 2: [existing behavior to preserve]
## Testable Assertions
1. `expect(processPayment(0)).toEqual({ amount: 0, status: 'completed' })`
2. `expect(processPayment(100)).toEqual({ amount: 100, status: 'completed' })`
3. `expect(() => processPayment(-1)).toThrow(InvalidAmountError)`
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