Typescript-checkstyle

Typescript-checkstyle is a tool for reporting typescript compiler output in checkstyle format. It was created to improve pull request decoration with compiler errors.

Prerequisites

Project requires:

• nodejs 10
• npm

Installation

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

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

Usage

Typescript-checkstyle can be used from command line and javascript.

Command line

Library reads tsc output from standard input. You may want to run both of them together. The following command typechecks your project and shows compilation errors in checkstyle format:

> npx tsc --noEmit | npx @bartekbp/typescript-checkstyle

If you already have npm scripts configured and want to use output from one of them to typescript-checkstyle, you need to invoke npm with --silent to suppress npm prologue:

> npm --silent run lint:tsc | npx @bartekbp/typescript-checkstyle

Pull request decoration with typescript errors

If you want to automate adding comments to your pull request based on complier output, typescript-checkstyle 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 typescript-checkstyle with tsc and redirect output to a file:

stage('tsc') {
  steps {
    sh  'npx tsc --noEmit | npx @bartekbp/typescript-checkstyle > tsc-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 "$CHANGE_ID" -v "CHECKSTYLE" "." ".*tsc-checkstyle.xml$" "tsc" || 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

Javascript

Typescript-checkstyle exposes one function format:

/**
 * Converts tsc errors to checkstyle format
 *
 * @param {string} input - errors from tsc
 * @return {string} errors in checkstyle format
 function format(input) {}
 */

You can use it as follows:

import format from '@bartekbp/typescript-checkstyle';

const input = `src/test.component.ts(3, 12): error TS2564: Property 'name' has no initializer`;
const errorsInCheckstyleFormat = format(input);
console.log(errorsInCheckstyleFormat);

This code prints out errors from input in checkstyle format.

License

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

Acknowledgements

Great thanks to:

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