Known Issues

This page contains a list of known issues when running Knip.

TS config files using ESM features

Knip may fail when a plugin tries to load a TypeScript configuration file (e.g. vite.config.ts) with an error message like one of these:

SyntaxError: Cannot use 'import.meta' outside a module
...
SyntaxError: await is only valid in async functions and the top level bodies of modules
...
SyntaxError: missing ) after argument list
...
SyntaxError: Unexpected identifier 'Promise'

This is caused by Knip using jiti to load and execute TypeScript configuration files that contains ESM syntax (such as top-level await), which may incorrectly consider it as CommonJS (instead of not transforming ESM).

Potential workarounds:

• Turn the configuration file from TS into JS (e.g. vitest.config.ts → vitest.config.js). Knip loads modules directly using native import() calls. This is the recommended workaround.
• Add the config file to the list of ignore patterns.
• Disable the plugin.

Use knip --debug in a monorepo to help locate where the error is coming from.

Issues like #72 and #194 are hopefully fixed in jiti v2. By the way, nothing but love for jiti (it’s awesome).

GitHub Issue #346

Reflect.metadata is not a function

Similar to the previous known issue, this is caused through (not by) jiti:

TypeError: Reflect.metadata is not a function

GitHub Issue #355