Enable env var hints for --token

[andersjanmyr]

Example:

$ ./fastly list service --token $FASTLY<tab>
$FASTLY_ACCOUNT_DEV         $FASTLY_ACCOUNT_SALJA_PROD
$FASTLY_ACCOUNT_PROD        $FASTLY_ACCOUNT_SANDBOX
$FASTLY_ACCOUNT_SALJA_DEV

[Integralist]

👋🏻 @andersjanmyr thanks for opening this PR!

Implementation looks OK, I just have a few requests.

[Integralist]

I have concerns about Windows support, it would be good to see a test implemented for the env package that validates the logic will work for Windows users. Our CI runs the CLI test suite on all three major platforms: macOS, Linux and Windows so if the test passes on all three then we'll know the implementation is good.

Example: set some environment variables and see if this function returns back the expected list of variables.

On Windows, I believe, the way to reference an environment variable is %VAR_NAME% so I presume os.Environ() will normalize the output so it works across platforms.

[andersjanmyr]

Yes, it probably needs some special treatment to handle Windows.

[Integralist]

@andersjanmyr out of interest, is there a reason you're using this approach rather than something like --profile (e.g. fastly service list --profile personal)?

[andersjanmyr]

@Integralist I was thinking of using profile locally, but we're using the same script to deploy both locally and on CI.
Something like this.

case "$env" in
  prod|stage)
    export FASTLY_API_KEY=$FASTLY_ACCOUNT_PROD
    ;;
  main)
    env='dev'
    export FASTLY_API_KEY=$FASTLY_ACCOUNT_DEV
    ;;
  *)
    export FASTLY_API_KEY=$FASTLY_ACCOUNT_DEV
    ;;
esac

[Integralist]

Other than two minor change requests this looks good to me.

Thanks!