Require commit messages contain a specific amount of alpha characters

[robouk]

In an effort to encourage helpful commit messages, I'm interested in the best approach to require a specific amount of alpha characters for each commit message.

I appreciate the responses - thanks.

[adammarkham · Accepted solution]

This is possible with the following custom pre-receive hook in ScriptRunner for Bitbucket Server.

You need to configure it by going to: Admin → Script Pre Hooks -> Custom script hook 

It will also display the commit ids that do not have a message with at least 10 alpha characters.

If you need alphanumeric you can replace the regex with /[A-Za-z0-9]/

import com.atlassian.bitbucket.hook.HookResponse
import com.atlassian.bitbucket.repository.RefChange
import com.atlassian.bitbucket.repository.Repository
import com.onresolve.scriptrunner.canned.bitbucket.util.BitbucketCannedScriptUtils

def refChanges = refChanges as Collection<RefChange>
def repository = repository as Repository
def hookResponse = hookResponse as HookResponse

def commits = refChanges.getCommits(repository)

def offendingCommits = commits.findAll { commit ->
    if (! commit.message) {
        return true
    }

	def regex = /[A-Za-z]/
    def alphaCharactersCount = (commit.message =~ regex).count

    alphaCharactersCount < 10
}

if (offendingCommits) {
    def msg = new StringBuilder()
    msg << "The following commits should have a message containing at least 10 characters:\n"

    offendingCommits.each { commit ->
        msg << commit.displayId
    }

    hookResponse.out().write(BitbucketCannedScriptUtils.wrapHookResponse(msg))

    return false
}

return true