rollup-pluginutils

Utility functions commonly needed by Rollup plugins, including file filtering (createFilter), scope analysis (attachScopes), identifier sanitization (makeLegalIdentifier), data-to-ESM conversion (dataToEsm), and extension handling (addExtension). This package is at version 2.8.2 and is stable but in maintenance mode; it has been superseded by `@rollup/pluginutils` for Rollup >= 1.0. TypeScript type definitions are included. Unlike ad-hoc implementations, these utilities are optimized for Rollup's plugin lifecycle and AST walking.