AGENTS.md

test

Manual test cases and UX behavior specifications that are impractical to automate.

When to add a new TC

• You fixed a UX bug that required human interaction to verify — document it here so it doesn't regress silently.
• You implemented a UX behavior with subtle invariants (z-order, modifier keys, pointer events) that would be fragile or verbose as code tests.
• You discovered an edge case during development that only manifests through real user interaction.

Do not add entries for pure logic, math, or data transformations — those belong in co-located __tests__/ or *.test.ts files.

How to add

1. Copy _template.md and rename: {module}-{area}-{short-description}.md
2. Assign a unique ID: TC-{MODULE}-{AREA}-{NNN} (increment NNN within the module+area)
3. Fill in all frontmatter fields — status starts as untested
4. Write the ## Behavior section as natural-language prose (design rationale, not just steps)
5. Write ## Steps with enough detail for someone unfamiliar to verify

How to reference from code

When code implements behavior documented here, add a comment pointing to the file:

// (see test/canvas-input-history-undo-cem.md)

Rules

• One behavior per file. If a TC covers two independent behaviors, split it.
• Never delete a TC — set status: deprecated instead (preserves history).
• When automating: write the code test, add its path to covered_by, set status: deprecated once fully covered.
• Keep prose stable. Frontmatter fields change freely, but avoid rewriting ## Behavior unless the actual behavior changed — git blame on that section is the audit trail.