Multiple & recursive expand

[javiacei]

Expand multiple variables

Now you can expand multiple variables using $ and ${}.

MONGOLAB_AUTH=$MONGOLAB_USER:${MONGOLAB_PASSWORD}

Recursive expand

MONGOLAB_USER_RECURSIVELY=${MONGOLAB_USER}:${MONGOLAB_PASSWORD}
MONGOLAB_URI_RECURSIVELY=mongodb://${MONGOLAB_USER_RECURSIVELY}@...

Multiple & recursive expand tests

Added more tests checking new functionalities.

[motdotla]

Thanks for this. I'll take a look soon.

[kashav]

I needed this feature for a project I'm working on, so I've been playing around with it. It seems to be overwriting preset variables (correct me if I'm wrong, but that's a bug).

Reproduce:

# .env
NODE_ENV=production

$ NODE_ENV=development node ./index.js

// index.js
const dotenv = require('dotenv')
const dotenvExpand = require('dotenv-expand')

dotenv.config()
console.log(process.env.NODE_ENV) //=> development (as expected)

dotenvExpand(dotenv.config())
console.log(process.env.NODE_ENV) //=> production (??)

---

I've found a fix in this block:

for (var configKey in config) {
  var value = process.env[configKey] || config[configKey]
  if (value.substring(0, 2) === '\\$') {
    config[configKey] = value.substring(1)
  } else {
    config[configKey] = interpolate(value)
  }
}

The problem seems to be that config maps to the object that was returned by dotenv.config, which doesn't use the preset environment variables, rather the parsed file contents. This isn't a bug, but perhaps dotenv.config should return both the compiled and raw variables (maybe another option to choose between the two)? (cc @motdotla)

[niftylettuce]

Meh, this still isn't fixed and the readme is still outdated per #2?

[rastasheep]

Any news? please?

[eliseumds]

?

[motdotla]

Thank you everyone for this PR and for your patience. It just merged here: #5

[motdotla]

Just published on npm as 4.0.0.

@kshvmdn 😱 you are absolutely right. I'll look into that right now.