[Home](./index.md) > [@userfrosting/merge-package-dependencies](./merge-package-dependencies.md) > [yarn](./merge-package-dependencies.yarn.md) ## yarn() function Merge specified yarn packages together. Signature: ```typescript export declare function yarn(template: TTemplate, paths: string[], saveTo?: string | null, log?: LogOption): TTemplate; ``` ## Parameters | Parameter | Type | Description | | --- | --- | --- | | template | TTemplate | Template that packages will be merged into. Is validated with \[package-json-validator\](https://www.npmjs.com/package/package-json-validator) with template.private == true overriding this. | | paths | string\[\] | Paths to package.json files. EG: "path/to/" (package.json is prepended) or "path/to/package.json" or "path/to/different.json". | | saveTo | string \| null | If string, saves the generated package.json to the specified path. Like 'paths', has 'package.json' prepended if required. | | log | [LogOption](./merge-package-dependencies.logoption.md) | If true, progress and errors will be logged. Has no affect on exceptions thrown. | Returns: TTemplate