handsontable

Use when writing tests for the Walkontable rendering engine - has its own separate test pipeline, runner, and configuration distinct from main Handsontable E2E tests

Use for ANY work touching the `handsontable/` core package: fixing bugs, adding features, modifying TypeScript types, removing as-casts, writing or debugging plugins, editors, renderers, validators, cell types, hooks, shortcuts, selection, helpers, index translations, or i18n. Also use for how-to questions about core internals (plugin lifecycle, coordinate systems, hook registration, TypeScript conventions). Triggers on file paths under `handsontable/src/` (excluding `3rdparty/walkontable/` which has its own skill), or when the user describes a symptom in the core grid without naming a file. This is the primary entry point for all core Handsontable development — when in doubt, load it.

Use when writing or modifying Jasmine/Puppeteer E2E tests (*.spec.js) for Handsontable, or when a bug fix or feature change needs E2E test coverage. Covers standard boilerplate, async/await rules, global helpers, event simulation, plugin lifecycle patterns, and writing theme-agnostic assertions that pass under all themes without branching on theme name.

Use when writing or modifying Jest unit tests (*.unit.js) or TypeScript type tests (*.types.ts) for Handsontable core, plugins, or utilities, or when a bug fix or internal refactor needs unit or type test coverage - covers Jest setup, test location conventions, mocking patterns, module aliases, type test patterns (no declare, real assignments, ESM + UMD patterns), and when to choose unit tests over E2E tests