[Home](./index.md) > [@userfrosting/merge-package-dependencies](./merge-package-dependencies.md) > [yarnIsFlat](./merge-package-dependencies.yarnisflat.md) ## yarnIsFlat() function Uses `yarn.lock` to detect if multiple versions of a dependency have been installed. Signature: ```typescript export declare function yarnIsFlat(p?: string, log?: LogOption): boolean; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | p | string | Directory of yarn.lock. | | log | [LogOption](./merge-package-dependencies.logoption.md) | If true, progress and errors will be logged. Has no affect on exceptions thrown. | Returns: boolean