This is a Bug Report

Description

• What went wrong?

In the serverless.yml file I have defined some environment variables:

provider:
  name: aws
  runtime: nodejs6.10
  profile: jagi
  environment:
    STAGE: ${opt:stage}

In some cases ${opt:stage} may be undefined, for example on localhost when using serverless-offline. When it's undefined it gets converted to the "undefined" string.

• What did you expect should have happened?

I would expect it to be just undefined. It's kinda weird to make comparisons like:

if (process.env.STAGE === 'undefined')

instead

if (process.env.STAGE === undefined)

Additional Data

• Serverless Framework Version you're using: 1.10.2
• Operating System: MacOS 10.12.4