GitHub Enterprise users should never be permitted to sign

[brianwarner]

Summary

EasyCLA permits signatures from GitHub Enterprise users, who cannot themselves contribute.

Background

GitHub Enterprise user accounts are incompatible with public GitHub. In order to contribute to any public project, you must use a public GitHub user account. Signatures from GitHub Enterprise users are not meaningful in the context of EasyCLA, because they will never map to a user account that can make a contribution. However, EasyCLA permits Enterprise users to sign CLAs, creating significant confusion on the part of the user - "I already signed this, why am I still blocked?" The correct behavior is to reject the signature from Enterprise users, and redirect them to sign with an account that is capable of contribution.

To reproduce:

1. Log into a GitHub Enterprise account
2. Sign an EasyCLA CLA.

GitHub Enterprise users can be easily identified by the use of an underscore _ in the username. Underscores are not valid in public GitHub usernames, which can only contain alphanumerics and -.

Expected behavior

GitHub Enterprise user accounts should not be eligible for signature. The signing flow should never start if the authenticated username contains an underscore _. Users should be notified that GitHub Enterprise accounts cannot sign EasyCLA CLAs on public GitHub repos.

Environment

Please complete the following information:

• Environment:
  • ALL
  • DEV
  • STAGING
  • PROD
• Browser:
  • Chrome/Brave
  • Firefox
  • Opera
  • Vivaldi
  • LibreWolf
  • SRware Iron
  • Dissenter
  • Slimjet
  • Midori
  • Edge
  • Lynx
• Version: v1.0.XX

Acceptance Criteria

1. GitHub Enterprise users are no longer presented with the option to sign an EasyCLA CLA.