Library reporting regex output in checkstyle format

regex, checkstyle, formatter
npm install @bartekbp/regex-checkstyle@5.0.0



Regex-checkstyle is a tool for finding mistakes in code using regexes and reporting them in checkstyle format. It was created to improve pull request decoration with typical sql errors.


Project requires:

  • nodejs 10
  • npm


All arifacts are published to npm. To use the latest version, you can install it using:

npm i --save-dev @bartekbp/regex-checkstyle


Library executes a regular expression over files with optional text substitution and reports results in checkstyle format. You can use it to find variables in code that begin with underscore and recommend to strip it:

> npx @bartekbp/regex-checkstyle -p '(const|let)\s+(_.*)' -s 'Variable $2 has a name starting with underscore. Please remove it.' 'src/**/*.js'

Supported parameters:

  • -p specifies regex to use for finding text
  • -s specifies substitution

The last positional argument is a glob that specifies searched files. For example glob values please refer to https://github.com/mrmlnc/fast-glob.

Pull request decoration with regex output

If you want to automate adding comments to your pull request based on regexes this tool will help you achieve it. To configure it, I will use jenkins, but the solution applies to other continuous integration systems as well.

Jenkins pipleline

You need to setup a jenkins pipeline that will be triggered with bitbucket branch source plugin or github branch source plugin. In the pipeline you need to run regex-checkstyle redirect output to a file:

stage('regex') {
  steps {
    sh  'npx @bartekbp/regex-checkstyle ... > regex-checkstyle.xml'

Depending on your code review system, tomasbjerre created different plugins for pull request decoration. You can find the full list of them at the bottom of violations-lib readme. I'll focus on the configuration for bitbucket cloud.

You need to update pipeline with additional stage for pr decoration:

stage('Decorate pr') {
  steps {
    withCredentials([usernamePassword(credentialsId: 'jenkins-pr-writes', passwordVariable: 'JENKINS_VIOLATION_PASSWORD', usernameVariable: 'JENKINS_VIOLATION_USER')]) {
      sh 'npx violation-comments-to-bitbucket-cloud-command-line -u "$JENKINS_VIOLATION_USER" -p "$JENKINS_VIOLATION_PASSWORD" -ws workspace -rs repoName -prid "$CHANGE_ID" -v "CHECKSTYLE" "." ".*regex-checkstyle.xml$" "regex" || true'

The bold parts in the stage needs to updated to reflect your project:

  • jenkins-pr-writes with credentials to bitbucket user
  • workspace with bitbucket workspace
  • repoName with repository that has an opened pull request


Distributed under the MIT License. See LICENSE for more information.


Great thanks to:

  • tomasbjerre for his tools enabling pull request decoration
  • jimf for tool to convert json to xml checkstyle format