# For agents: Tests are contracts too

The ideal OpenProse · board 10 of 17 · 2026-10-09.
This deck describes a proposed experience.

Test a checker with a controlled defect and a separately held expected finding.

## On the slide

Subject contract + fixture world + observation + evaluation

**Can the test distinguish acceptable work from a consequential defect?**

Expected violation detected → test passes

## Explanation

The testing agreement says what to exercise and what evidence would establish the expected property. A fixture contract supplies a known world; an observation contract supplies the required observations; an evaluator assesses them. For our example, supply an altered candidate that retains a material claim while its sole supporting evidence is removed. Assess that candidate without repairing it. A useful negative test should detect the unsupported claim. Its subject can fail while the test passes, because detection was the test's requirement. Also try a differently worded but valid document: a checker that rejects every variation is inadequate. The setup must actually keep evaluator-only answers out of the subject's context.

This slide constructs a controlled experiment. The next slide supplies reusable judgments about executions, whether produced by a test or by ordinary work. The test can select those checking contracts as evaluators and state the findings expected for its case. Retained failures and valid alternatives can also become cases for testing the checkers themselves.

## Whiteboard sequence

Open only the frames useful to the question. Later frames add to the same board;
the final frame contains the complete drawing.

- [Frame 1 — black core](https://prose.md/visual-guide/2026-10-09/ideal/slide-10-layer-01.png)
- [Frame 2 — cumulative reveal](https://prose.md/visual-guide/2026-10-09/ideal/slide-10-layer-02.png)
- [Frame 3 — final](https://prose.md/visual-guide/2026-10-09/ideal/slide-10-layer-03.png)

These explanations add no normative requirements. Read the
[selected kernel 0.3.0-rc.3](https://pkg.prose.md/releases/0.3.0-rc.3/core/README.md) for language rules.

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[All The ideal OpenProse boards](https://prose.md/visual-guide/ideal.md) · [Guide index](https://prose.md/visual-guide.md) · [Agent entry](https://prose.md/agents.md)