eslint-plugin-expect-type

ESLint plugin that adds Twoslash-style type assertions ($ExpectType, $ExpectError, $ExpectTypeSnapshot) and the ^? hover type comment. Version 0.6.2 is the latest stable release as of early 2025, with active development and frequent releases (0.4.x to 0.6.x in rapid succession). Unlike runtime assertion libraries (expect-type, ts-expect), this plugin works at the ESLint linting level without test runners. Requires @typescript-eslint/parser ≥6, ESLint ≥7, and TypeScript ≥4. Unique for inline type assertions in comments, enabling type-level testing in any file linted by ESLint.