Red First

Red-First, Tamper-Proof

Effort: free — pure ordering discipline: the test you would write anyway is written first, proven red, and sealed with one commit; the tamper check is a single git diff. Removes: tests shaped after the fix to pass, and green verdicts a builder bent by editing the test.

A test written after the fix proves nothing — it was shaped to pass. A test the builder can edit proves less — it can be bent to pass. So the test comes first, gets locked, and is graded untouched.

When to run it

Before dispatching any build or fix where a test can state the wanted behavior. This is the default for bug fixes and new capabilities alike.

Steps

1. Write the failing contract test. It states the behavior you want, in the smallest form that would catch its absence. It must fail right now.
2. Prove it red. Run the test and watch it fail — for the right reason. A test that errors on import, or quietly passes, is not red. A red test nobody ran is a guess, not a baseline.
3. Commit the red test BEFORE dispatching the builder. Record the commit id. That commit is the red baseline — the tamper seal.
4. Dispatch the builder with one job: make it green. The builder is forbidden to touch the test file. Say so in the dispatch.
5. Grade independently. A grader who did not author the change checks two things:
   • the test now passes;
   • the test file is byte-identical to the red baseline — git diff <red-sha> HEAD -- tests/test_contract.py prints nothing. Any diff on the test file fails the grade. No exceptions, not even "just fixed a typo."
6. Prefer one structural guard over scattered point tests. A structural guard is a check (a grep sweep, an AST scan, a lint rule) that fails on the NEXT offender, not just this instance. One guard beats ten point tests that each pin one case.

Hard rules

• Red must be proven red. Run it, watch it fail, before it counts.
• The builder never edits the test. The empty test-file diff since the red baseline is part of the landing gate, not a courtesy check.
• Builder is never the grader. Use a different person, agent, or a model from a different family than the builder.
• Green alone is not proof. Green + untouched test + independent grade is proof.
• When a whole class of defect is in play, guard the class. Point tests stop this bug; a structural guard stops the next one.

Works well with

• sniper-testing — run only the tests the change touches while iterating; one full pass at landing.
• seam-engineering — the class-fix discipline the structural guard belongs to.
• blind-tribunal — independent graders who never saw the author.
• repair-loop — the loop that carries red → green → proven end to end.