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no-legacy-module-resolution

Disallow deprecated module resolution strategies such as "classic" and "node" in favor of modern alternatives.

Targeted pattern scopeโ€‹

The compilerOptions.moduleResolution field in any tsconfig*.json file.

What this rule reportsโ€‹

This rule reports when moduleResolution is set to "classic" or "node". Both strategies predate modern Node.js ESM and bundler resolution conventions and do not correctly model the module resolution semantics of current tooling.

Why this rule existsโ€‹

"classic" was TypeScript's original resolution algorithm and is no longer suitable for any real-world project. It does not understand node_modules, exports fields in package.json, or path aliases.

"node" (also written "node10") models the CommonJS resolution algorithm from Node.js 10 and earlier. It does not understand exports field package conditions, .js extension requirements for ESM, or dual CJS/ESM packages. Projects using this strategy often silently accept extension-less imports that fail at runtime in modern Node.js or browser environments.

The modern replacements are:

  • "NodeNext" or "Node16" for Node.js projects with ESM or dual CJS/ESM.
  • "Bundler" for projects processed by a bundler like Vite, esbuild, or webpack.

โŒ Incorrectโ€‹

{
    "compilerOptions": {
        "moduleResolution": "node"
    }
}
{
    "compilerOptions": {
        "moduleResolution": "classic"
    }
}

โœ… Correctโ€‹

For a Node.js ESM project:

{
    "compilerOptions": {
        "module": "NodeNext",
        "moduleResolution": "NodeNext"
    }
}

For a bundled frontend project:

{
    "compilerOptions": {
        "module": "ESNext",
        "moduleResolution": "Bundler"
    }
}

When not to use itโ€‹

Disable this rule when maintaining a legacy codebase that cannot yet migrate from node resolution, and the migration is tracked as a separate work item.

Package documentationโ€‹

Rule catalog ID: R011

Further readingโ€‹