netlify-cli/src/utils/dot-env.js

Netlify command line tool

const path = require('path')
const process = require('process')

const dotenv = require('dotenv')
const filterObject = require('filter-obj')

const { isFileAsync, readFileAsync } = require('../lib/fs')

const loadDotEnvFiles = async function ({ projectDir, warn }) {
  const dotenvFiles = ['.env.development', '.env']
  const results = await Promise.all(
    dotenvFiles.map(async (file) => {
      const filepath = path.resolve(projectDir, file)
      try {
        const isFile = await isFileAsync(filepath)
        if (!isFile) {
          return
        }
      } catch (error) {
        warn(`Failed reading env variables from file: ${filepath}: ${error.message}`)
        return
      }
      const content = await readFileAsync(filepath)
      const parsed = dotenv.parse(content)
      // only keep envs not configured in process.env
      const env = filterObject(parsed, (key) => !Object.prototype.hasOwnProperty.call(process.env, key))
      return { file, env }
    }),
  )

  return results.filter(Boolean)
}

module.exports = { loadDotEnvFiles }