fpj: Find Package Json

fpj Resolves The Location Of The Package.Json File For The Given Dependency By Traversing The File System Up Starting From Given Path.

yarn add -E fpj

Table Of Contents

• Table Of Contents
• API
• async fpj(dirname: string, packageName: string, opts?: FPJConfig): FPJReturn
  • _fpj.Config
  • _fpj.Return
• Fields
• Soft Mode
• Copyright

API

The package is available by importing its default function:

import fpj from 'fpj'

async fpj(
  dirname: string,
  packageName: string,
  opts?: FPJConfig,
): FPJReturn

Returns the resolved entry point to the package. It will start checking for the presence of packages using Node's algorithm by resolving the node_modules folder first inside of the given dirname, then if not found, traverse up and repeat, until root of the OS is reached.

The preference of the entry output will be given to the module field specified in the package.json. If the main is found instead, it will be indicated with hasMain property on the returned object.

_fpj.Config: The options for fpj.

Name	Type	Description	Default
fields	!Array<string>	Any additional fields from package.json file to return.	-
soft	boolean	If the entry export (main or module) does not exist, soft mode will not throw an error, but add the hasEntry property to the output set to false.	false

For example, the package.json files and meta information for 2 packages can be fetched using the following example:

/* yarn example/ */
import fpj from 'fpj'
import { dirname } from 'path'

(async () => {
  const zoroaster = await fpj(
    dirname('example/example.js'),
    'zoroaster'
  )
  console.log(zoroaster)
  const read = await fpj(
    dirname('example/example.js'),
    '@wrote/read'
  )
  console.log(read)
})()

FPJ gives preference to the module field and will report it as the entry if it exists. Otherwise, the main is used with the hasMain property set to true:

{
  entry: 'node_modules\\zoroaster\\depack\\index.js',
  packageJson: 'node_modules\\zoroaster\\package.json',
  version: '4.3.0',
  packageName: 'zoroaster',
  hasMain: true
}
{
  entry: 'node_modules\\@wrote\\read\\src\\index.js',
  packageJson: 'node_modules\\@wrote\\read\\package.json',
  version: '1.0.4',
  packageName: '@wrote/read'
}

_fpj.Return: The return type of the program.

Name	Type	Description
entry*	string	The location of the package's entry file. The preference is given to the module field.
packageJson*	string	The path to the package.json file itself.
packageName*	string	The name of the resolved package.
version	string	The version of the package.
hasMain	boolean	Whether the entry is the main rather than module.
entryExists	boolean	In soft mode, will be set to false if the entry file does not exist.

Fields

Any additional fields from package.json that need to be present in the output can be specified in the fields property.

/* yarn example/ */
import fpj from 'fpj'
import { dirname } from 'path'

(async () => {
  const zoroaster = await fpj(
    dirname('example/example.js'),
    'zoroaster',
    { fields: ['license', 'bin'] },
  )
  console.log(zoroaster)
})()

{
  entry: 'node_modules\\zoroaster\\depack\\index.js',
  packageJson: 'node_modules\\zoroaster\\package.json',
  version: '4.3.0',
  packageName: 'zoroaster',
  hasMain: true,
  license: 'AGPL-3.0',
  bin: {
    zoroaster: 'depack/bin/zoroaster.js',
    'zoroaster-dev': 'src/bin/index.js'
  }
}

Soft Mode

When a package exports either a main or a module fields, fpj will check for their existence to resolve the path to the entry. When the entry does not exist, by default an error will be thrown. To disable the error, and add the entryExists: false to the output, the Soft Mode can be activated.

/* yarn example/ */
import fpj from 'fpj'
import { dirname } from 'path'

(async () => {
  const zoroaster = await fpj(
    dirname('example/example.js'),
    'myPackage',
    { soft: true },
  )
  console.log(zoroaster)
})()

{
  entry: 'example\\node_modules\\myPackage\\index.js',
  packageJson: 'example\\node_modules\\myPackage\\package.json',
  version: '1.0.0',
  packageName: 'myPackage',
  hasMain: true,
  entryExists: false
}

Copyright

	© Art Deco™ 2020