Invalid regex in `commitConfig` causes pushes to crash/error out

[jescalada]

When setting invalid regex for the patterns in commitConfig, pushes either fail (in the case of commitConfig.author.email.local.block) or give a misleading error (in the case of commitConfig.message.block.patterns.

Invalid author config:

"author": {
  "email": {
    "local": {
      "block": "[invalid"
    },
    "domain": {
      "allow": "(?<invalid"
    }
  }
},

Output:

Invalid message config:

"message": {
  "block": {
    "literals": ["safe"],
    "patterns": [
      "[unclosed",
      "(?<incomplete",
      "*invalid",
      "(?P<invalid>",
      "\\k<notdefined>"
    ]
  }
},

Output:

Invalid diff config:

"diff": {
  "block": {
    "literals": [],
    "patterns": [
      "[unclosed",
      "(?<incomplete"
    ],
    "providers": {
      "Bad Provider": "*starts-with-quantifier",
      "Unclosed Group": "(forgot to close"
    }
  }
}

Output:

Describe the solution you'd like
These are likely fixed by improving the error handling in the checkCommitMessages.ts, checkAuthorEmails.ts and scanDiff.ts processors. We should make sure each action gives a descriptive error on invalid regex but blocks the push instead of crashing.

Additional context
Found when writing documentation for the chain in #1335

[kriswest]

It could be dangerous to 'handle' these errors at runtime, in that commits might pass that should not. Perhaps it would be best to check these configs at start-up and fail out if they are invalid?

[kriswest]

On re-reading your comment I note that you say commits should be blocked 👍
Making each of those processors more consistent in their handling would be good. If doing that, I think knocking up a util function to check each regex on start-up and whenever config is loaded would be a good idea. I think blocking start-up if our config is invalid is the best approach as it guarantees that config issues don't go unnoticed.