vue-cli/packages/@vue/cli/lib/util/getPkg.js

// Get the package.json containing all the `vue-cli-pluin-*` dependencies
// See issue #1815

const fs = require('fs')
const path = require('path')

function getPackageJson (projectPath) {
  const packagePath = path.join(projectPath, 'package.json')

  let packageJson
  try {
    packageJson = fs.readFileSync(packagePath, 'utf-8')
  } catch (err) {
    throw new Error(`The package.json file at '${packagePath}' does not exist`)
  }

  try {
    packageJson = JSON.parse(packageJson)
  } catch (err) {
    throw new Error('The package.json is malformed')
  }

  return packageJson
}

module.exports = function getPkg (context) {
  const pkg = getPackageJson(context)
  if (pkg.vuePlugins && pkg.vuePlugins.resolveFrom) {
    return getPackageJson(path.resolve(context, pkg.vuePlugins.resolveFrom))
  }
  return pkg
}