npm-dependencies-merge is a nifty little script that scans subdirectories searching for nested package.json files, and merges all the dependencies together in a single package.json file that is outputted to stdout.

A base template passed through standard input is used to produce the root package.json file. This allows package.json to be ignored by version control systems, which conflict with auto-generated files. Base package attributes, like name and version, can be stored in a separate file such as package-base.json, and kept in version control.

$ cd project_directory
$ npm-dependencies-merge < package-base.json > package.json

$ npm install -g npm-dependencies-merge

-h, --help           output usage information
-V, --version        output the version number
-s, --silent         do not print out warnings
-c, --combine        combine dependencies and devDependencies
-f, --files          files to search for (Default: package.json)
-o, --output [file]  output to a file

npm-dependencies-merge will warn you about any potential conflicts of the versions declared in the multiple package.json files