npm
@npmcli/package-json
Programmatic API to update package.json files. Updates and saves files the
same way the npm cli handles them.
Install
npm install @npmcli/package-json
Usage:
const PackageJson = require('@npmcli/package-json')
const pkgJson = await PackageJson.load(path)
// $ cat package.json
// {
// "name": "foo",
// "version": "1.0.0",
// "dependencies": {
// "a": "^1.0.0",
// "abbrev": "^1.1.1"
// }
// }
pkgJson.update({
dependencies: {
a: '^1.0.0',
b: '^1.2.3',
},
workspaces: [
'./new-workspace',
],
})
await pkgJson.save()
// $ cat package.json
// {
// "name": "foo",
// "version": "1.0.0",
// "dependencies": {
// "a": "^1.0.0",
// "b": "^1.2.3"
// },
// "workspaces": [
// "./new-workspace"
// ]
// }There is also a helper function exported for opening a package.json file with no extra normalization or saving functionality.
const { readPackage } = require('@npmcli/package-json/lib/read-package')
const rawData = await readPackage('./package.json')
// rawData will now have the package.json contents with no changes or normalizationsAPI:
constructor()
Creates a new empty instance of PackageJson.
async PackageJson.create(path)
Creates an empty package.json at the given path. If one already exists
it will be overwritten.
async PackageJson.load(path, opts = {})
Loads a package.json at the given path.
opts:Objectcan contain:create:Booleanif true, a new package.json will be created if one does not already exist. Will not clobber ane existing package.json that can not be parsed.
Example:
Loads contents of a package.json file located at ./:
const PackageJson = require('@npmcli/package-json')
const pkgJson = new PackageJson()
await pkgJson.load('./')Throws an error in case a package.json file is missing or has invalid contents.
static async PackageJson.load(path)
Convenience static method that returns a new instance and loads the contents of a package.json file from that location.
path:Stringthat points to the folder from where to read thepackage.jsonfrom
Example:
Loads contents of a package.json file located at ./:
const PackageJson = require('@npmcli/package-json')
const pkgJson = await PackageJson.load('./')async PackageJson.normalize()
Intended for normalizing package.json files in a node_modules tree. Some light normalization is done to ensure that it is ready for use in @npmcli/arborist
path:Stringthat points to the folder from where to read thepackage.jsonfromopts:Objectcan contain:strict:Booleanenables optional strict mode when applying thenormalizeDatastepsteps:Arrayoptional normalization steps that will be applied to thepackage.jsonfile, replacing the default stepsroot:Pathoptional git root to provide when applying thegitHeadstepchanges:Arrayif provided, a message about each change that was made to the packument will be added to this array
static async PackageJson.normalize(path, opts = {})
Convenience static that calls load before calling normalize
path:Stringthat points to the folder from where to read thepackage.jsonfromopts:Objectcan contain:strict:Booleanenables optional strict mode when applying thenormalizeDatastepsteps:Arrayoptional normalization steps that will be applied to thepackage.jsonfile, replacing the default stepsroot:Pathoptional git root to provide when applying thegitHeadstepchanges:Arrayif provided, a message about each change that was made to the packument will be added to this array
async PackageJson.prepare()
Like normalize but intended for preparing package.json files for publish.
static async PackageJson.prepare(path, opts = {})
Convenience static that calls load before calling prepare
path:Stringthat points to the folder from where to read thepackage.jsonfromopts:Objectcan contain:strict:Booleanenables optional strict mode when applying thenormalizeDatastepsteps:Arrayoptional normalization steps that will be applied to thepackage.jsonfile, replacing the default stepsroot:Pathoptional git root to provide when applying thegitHeadstepchanges:Arrayif provided, a message about each change that was made to the packument will be added to this array
async PackageJson.fix()
Like normalize but intended for the npm pkg fix command.
PackageJson.update(content)
Updates the contents of a package.json with the content provided.
content:Objectcontaining the properties to be updated/replaced in thepackage.jsonfile.
Special properties like dependencies, devDependencies,
optionalDependencies, peerDependencies will have special logic to handle
the update of these options, such as sorting and deduplication.
Example:
Adds a new script named new-script to your package.json scripts property:
const PackageJson = require('@npmcli/package-json')
const pkgJson = await PackageJson.load('./')
pkgJson.update({
scripts: {
...pkgJson.content.scripts,
'new-script': 'echo "Bom dia!"'
}
})NOTE: When working with dependencies, it's important to provide values for all known dependency types as the update logic has some interdependence in between these properties.
Example:
A safe way to add a devDependency AND remove all peer dependencies of an
existing package.json:
const PackageJson = require('@npmcli/package-json')
const pkgJson = await PackageJson.load('./')
pkgJson.update({
dependencies: pkgJson.content.dependencies,
devDependencies: {
...pkgJson.content.devDependencies,
foo: '^foo@1.0.0',
},
peerDependencies: {},
optionalDependencies: pkgJson.content.optionalDependencies,
})get PackageJson.content
Getter that retrieves the normalized Object read from the loaded
package.json file.
Example:
const PackageJson = require('@npmcli/package-json')
const pkgJson = await PackageJson.load('./')
pkgJson.content
// -> {
// name: 'foo',
// version: '1.0.0'
// }async PackageJson.save()
Saves the current content to the same location used when calling
load().