RegExp to match conventional commit syntax

Question

I've been fiddling around this since yesterday.
I just can't seem to match all the possible cases.

I'm trying to come up with a regular expression which matches a Conventional Commit, but which also offers some error recovery functionality.

Current regexp:

(?<type>build)(?<scope>\(.*\)?(?=:))?(?<breaking>!)?(?<subject>:.*)?

Inputs:

build(one)
build(two)!
build(three)!:test
build(example:module)!: test
build: test
build(<> : dda!sd): test
build(:
build

Outputs:

What doesn't work:

• first two cases
• the ! isn't captured as breaking in the third and following cases

---

The sample is at Regex101, https://regex101.com/r/XYC04q/1
And I have other (16) tests here, https://regex101.com/r/sSrvyA/11

Even if you have no time to try and modify it, any comment is appreciated.

Answer 1

Doesn't necessarily solve the desire to capture )!: as breaking group but this does seem to follow conventional commits specs 1-5 + 13.

^(?<type>build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\_\(ツ\)_\/¯)(?<scope>\(\w+\)?((?=:\s)|(?=!:\s)))?(?<breaking>!)?(?<subject>:\s.*)?|^(?<merge>Merge \w+)

https://regex101.com/r/XYC04q/11

Gitlab Push Commit Regex

However, if you are using a platform like GitLab and want to set push rule to commit messages as of v13(?) they are using re2 standards and Golang parser.

Here it is for that Gitlab.

Note that GitLab enables the global flag (?m) which gave me some difficulty. Discussion on gitlab

| Restrict by commit message | Starter 7.10 | Only commit messages that match this regular expression are allowed to be pushed. Leave empty to allow any commit message. Uses multiline mode, which can be disabled using (?-m). |

source doc

## simplified and modified for gitlab's 
^((build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\_\(ツ\)_/¯)(\(\w+\))?(!)?(: (.*\s*)*))|(Merge (.*\s*)*)|(Initial commit$)

## RE2 compliment but doesn't work on GitLab at this time
^(?P<type>build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\_\(ツ\)_/¯)(?P<scope>\(\w+\))?(?P<breaking>!)?(?P<subject>:\s.*)?|^(?P<merge>Merge \w+)

https://regex101.com/r/XYC04q/28

GitLab using Terraform Push Rule Regex

Note if you are trying to use Terraform for Gitlab with Regex, note that Terraform parses the string prior to Gitlab requiring some bonus escapes.

resource "gitlab_project_push_rules" "github_flow" {
  project = gitlab_project.project.id

  # Conventional Commits https://www.conventionalcommits.org/en/v1.0.0/
  commit_message_regex = "^((build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\\\_\\(ツ\\)_/¯)(\\(\\w+\\))?(!)?(: (.*\\s*)*))|(Merge (.*\\s*)*)|(Initial commit$)"
  branch_name_regex    = "(^(build|chore|ci|docs|feat|fix|perf|refactor|revert|style|test|¯\\\\_\\(ツ\\)_\\/¯)\\/[a-z0-9\\-]{1,55}$)|master"

  prevent_secrets = true
}

Answer 2

You have some optional parts for which you could indeed a non capturing group to match either from an opening ( till a closing ) or match only an opening (

(?<type>build)(?<scope>(?:\([^()\r\n]*\)|\()?(?<breaking>!)?)(?<subject>:.*)?

• (?<type>build) Group type, match build
• (?<scope> Group scope
  • (?: Non capturing group
    • \([^()\r\n]*\) Match either from opening ( till closing )
    • | or
    • \( Match a single (
  • )? Close non capturing group and make it optional
  • (?<breaking>!)? Optional group breaking
• ) Close group scope
• (?<subject>:.*)? Optional group subject

Regex demo