Deterministic Project Selection in ESLint parserOptions.project for Monorepos

ESLint’s parserOptions.project accepts an array of TypeScript project file paths, enabling type‑aware linting across a monorepo.

The specification does not define a deterministic order for loading these projects, so rule evaluation can vary depending on load sequence or differing ESLint versions, resulting in nondeterministic lint outcomes.

What criteria should ESLint use to establish a stable precedence when multiple parserOptions.project entries are provided? How should the tool handle conflicts between projects that reference different parser plugin versions? Is there a recommended practice to verify consistent type checking across all selected projects?

• How should ESLint define project loading order when multiple parserOptions.project entries are specified?
• What error handling is required when conflicting projects reference different parser plugin versions?
• Is there a documented method to enforce consistent type checking across multiple projects in a monorepo?