[NT-620] Skip danger for external contributors

[justinswart]

📲 What

Does not run Danger on PRs from external contributors.

🤔 Why

We received an external contribution recently and the CircleCI workflow that runs Danger is failing because it does not have access to DANGER_GITHUB_API_TOKEN.

🛠 How

• Moved the command that we previously used to execute Danger into a bash script and updated it so that it will not run if this environment variable is not available.
  • This is the solution described in Danger's docs for not exposing environment vars - https://danger.systems/guides/troubleshooting.html#i-want-to-only-run-danger-for-internal-branches
• CircleCI also recommends explicitly disabling passing of secrets to builds that run on forks.

👀 See

✅ Acceptance criteria

• Danger still runs on our own branches.
• Once this is merged into Show/Hide Password button overridden by orientation change  #949, all CircleCI workflows should pass.

[ifbarrera]

Would this print "Skipping Danger For External Contributor" if bundle exec danger --verbose fails for any reason? 🤔 My bash scripting skills are very weak I admit.

[Scollaco]

They don't say much about it on their website, but I believe that it means "If you don't have the token and try to execute this command, print that".

[ifbarrera]

I guess I'm more wondering about the case where the token is present, but bundle exec danger returns a false value for some reason.

[justinswart]

Good catch @ifbarrera, I've updated the script to fail under normal circumstances with:

Otherwise, yes - it would just say "Skipping Danger For External Contributor" for any failure reason.

[Scollaco]

lgtm!