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Prove that a repair fixes the defect

Use an unchanged acceptance condition to judge an AI-assisted code change.

Read the concept. Explore two decisions. Leave with a test you would run next.

The working model

Understand the boundary.

A coding assistant needs a concrete way to verify its work. Establish the required behavior before editing, reproduce the failure, and inspect the final change. A passing check is useful only if it tests the behavior you actually need.

Reproduce
Capture the failing behavior
Repair
Change the implementation
Verify
Replay the same acceptance case

A worked example

A fictional scheduling tool displays the wrong local date near midnight. Record the input instant and required time zone, reproduce the incorrect date, then use that case to test a repair. Changing the expected date to match the bug would make the test green without repairing the product.

Claude Code: verification practices

Primary reading checked 2026-10-10. Provider learning stays with its issuer.

Practice deskDecision 1 of 2

Make a decision

The assistant changes the date formatter and updates the failing test's expected date. The full test suite now passes.

What would make this repair credible?

Choose one response before comparing the reasoning.The green suite is sufficient evidence.Restore the required expectation and show it failing before the repair and passing after.Ask several models whether the patch looks right.

Another concept

Connect a tool without lending it authority

Open the next free exercise

For teams

Build evidence through real work.

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