assay

assay

Build regression tests around observable behaviour and demonstrate that they detect the fault. Use for test design, missing coverage, and validating a code change.

Inputs

Behaviour or defect to protect; observable acceptance examples; target project; its actual test command and supported test environment.

Run record

Use checklist 0.5 or newer for this SOP. Reading or reloading the skill must not reset work. For a new task, run checklist init "${CLAUDE_SKILL_DIR}" --new --path "/absolute/project"; retain its returned ID as RUN. For existing work, use checklist resume "$RUN", then checklist show --run "$RUN". Outside Claude, replace the skill-directory variable with this directory’s actual path.

Commands below record work after it is done. Replace evidence placeholders with concise artifact locations and observations. Manual confirmations are not independent proof; a sensor pass covers only the command and inputs it observed. verify does not close a stage; advance checks that its required readings are fulfilled. Use report --run "$RUN" for the retained history.

Before starting, inspect the project and bind TEST_CMD to its real trusted command with --var 'TEST_CMD=<actual command>'. Do not use an echo/no-op to produce a green result. checklist resume "$RUN" --var 'TEST_CMD=<new command>' changes the binding and invalidates earlier readings; commands and output are stored locally, so do not bind secrets.

Procedure

contract

Translate the requirement into examples and identify the cheapest level that observes the real behaviour. Name external boundaries and decide which may be substituted without replacing the subject of the test.

Record these artifacts after doing the work:

• Acceptance examples name observable outcomes and relevant edge cases. checklist check contract behaviour --run "$RUN" --evidence "<artifact and observation>"
• Test level and any doubles preserve the behaviour under test. checklist check contract boundary --run "$RUN" --evidence "<artifact and observation>"