SOMOD package.json

SOMOD makes some changes to the original specification of package.json.

The package.json is validated before every build of the SOMOD module to ensure its correctness.

The following properties in the package.json object have a particular purpose in the SOMOD module.

• name
  The name of the npm package is the name of the SOMOD module.

• version
  SOMOD suggests having semantic versioning. Read more on semantic versioning here.

• description
  Describe the SOMOD module in this property. The SOMOD module must contain a description.

• module
  The build step in SOMOD creates javascript in ES6 module format at the build directory. Webpack and other bundlers use the module property to resolve the entry point for an ES6 module. SOMOD always generates the entry point at build/lib/index.js, hence this property must have a hardcoded value of build/lib/index.js.

• sideEffects
  The sideEffects property is an instruction to the bundler that it can prune all of the code from this package. The SOMOD module must have this property set to false.

• main, jsnext:main, type
  These properties make the bundlers fail when resolving the ES6 modules. Hence the use of these properties is not allowed in the SOMOD module.

• typings
  The typings property points to the entry point of the type declaration file. SOMOD module generates the sharable types at build/lib/index.d.ts, hence this property must have a hardcoded value of build/lib/index.js. More on type declarations is here.

• files
  The files property is an array of file patterns that describes the entries to be included in the package. SOMOD builds source code into the build directory. So files property must include the "build" in the array.

• somod
  The somod property differentiates other npm packages from SOMOD modules. NPM packages containing somod property in package.json are considered SOMOD modules. The somod build command sets this to the version of SOMOD CLI used during the build.

• dependencies
  SOMOD modules can have any npm library as a dependency when needed.

• devDependencies
  SOMOD module must install somod npm package as a dev dependency along with other required packages based on the type of the module.

  • module containing the serverless code must install @types/aws-lambda, aws-sdk, and somod-middleware as dev dependencies
  • module containing the ui code must install @types/react, react, next, and react-dom as dev dependencies.

  Also, any other npm library can be installed as a dev dependency when needed.

Otherwise documented, all other properties in package.json behave as defined in the original specification.

Sample package.json

{
  "name": "my-module",
  "version": "1.0.0",
  "module": "build/lib/index.js",
  "typings": "build/lib/index.d.ts",
  "files": ["build"],
  "sideEffects": false,
  "somod": "1.13.3",
  "devDependencies": {
    "somod": "^1.13.3"
  }
}

In our next section, we will explore the directory structure of a SOMOD module.