[#61]: evPushSender can be null

[roberth]

Issue reference:

Fixes #61
GitHub sometimes sends a pull event without a sender. See the anonymized test case.

Submission Checklist:

• Have you followed the guidelines in our Contributing document (for example, is your tree a clean merge)?
  • Broken link
• Have you checked to ensure there aren't other open Pull Requests for the same update/change?
• Does your submission build?
  • built on linux with haskell.nix
• Does your submission pass tests?
• Have you run lints on your code locally prior to submission?
• Have you updated all of the cabal/nix infrastructure?
• Is this a breaking change? Have you discussed this?
  • Formally it is a breaking change, as PushEvent consumers may have to handle a Nothing, but this merely reflects the reality of github webhooks. sender may be omitted in rare cases.

[kvanbere]

Hi Robert, thanks for the PR!

I'm currently away, but I'll take a look and get back to you within the next day or so.

[kvanbere]

@roberth Changes look good, but I want to run the CI over this. I have to make a few changes so that it can be run on a remote fork since the GitHub push event does not trigger due to the way this was raised.

[kvanbere]

See inline comment on CI failure for mempty.

[kvanbere]

Looks like the CI has raised warnings that we forgot to export EventHasMaybeSender(..).

[kvanbere]

Hi Rob, thanks for that revision. According to CI, it looks like one of the examples (github-webhooks-servant-example) needs to be updated to match this change to the API:

2022-12-13T00:51:21.1290270Z github-webhooks-servant-example       > Configuring github-webhooks-servant-example-0.0.0...
2022-12-13T00:51:21.3253306Z github-webhooks-servant-simple-example> configure (exe)
2022-12-13T00:51:21.3257387Z github-webhooks-servant-example       > build (exe)
2022-12-13T00:51:21.4035215Z github-webhooks-servant-example       > Preprocessing executable 'github-webhooks-servant-example' for github-webhooks-servant-example-0.0.0..
2022-12-13T00:51:21.4036052Z github-webhooks-servant-example       > Building executable 'github-webhooks-servant-example' for github-webhooks-servant-example-0.0.0..
2022-12-13T00:51:21.5255894Z github-webhooks-servant-example       > [1 of 2] Compiling Main
2022-12-13T00:51:21.9723780Z github-webhooks-servant-simple-example> Configuring github-webhooks-servant-simple-example-0.0.0...
2022-12-13T00:51:22.0500611Z github-webhooks-servant-example       > 
2022-12-13T00:51:22.0502246Z github-webhooks-servant-example       > /home/runner/work/github-webhooks/github-webhooks/examples/servant/src/Main.hs:38:38: error:
2022-12-13T00:51:22.0502986Z github-webhooks-servant-example       >     • Couldn't match type ‘Maybe HookUser’ with ‘HookUser’
2022-12-13T00:51:22.0503531Z github-webhooks-servant-example       >       Expected type: PushEvent -> HookUser
2022-12-13T00:51:22.0504386Z github-webhooks-servant-example       >         Actual type: PushEvent -> Maybe HookUser
2022-12-13T00:51:22.0504908Z github-webhooks-servant-example       >     • In the second argument of ‘(.)’, namely ‘evPushSender’
2022-12-13T00:51:22.0505409Z github-webhooks-servant-example       >       In the second argument of ‘(.)’, namely
2022-12-13T00:51:22.0505871Z github-webhooks-servant-example       >         ‘whUserLogin . evPushSender’
2022-12-13T00:51:22.0506373Z github-webhooks-servant-example       >       In the expression: show . whUserLogin . evPushSender
2022-12-13T00:51:22.0506787Z github-webhooks-servant-example       >    |
2022-12-13T00:51:22.0507361Z github-webhooks-servant-example       > 38 |     putStrLn $ (show . whUserLogin . evPushSender) ev ++ " pushed a commit causing HEAD SHA to become:"
2022-12-13T00:51:22.0507911Z github-webhooks-servant-example       >    |  

https://github.com/cuedo/github-webhooks/actions/runs/3681095902/jobs/6227414754

The examples are designed to be overly-simple, so I think using fromJust would be fine here.

[roberth]

Thanks for helping!