Comic Relief Pattern Lab

A Node-based project to supply Sass components and a styleguide generator.

The idea

To have a centralised hub supply common styling across Comic Relief products.

Quicklinks

Styleguide

Workflow

Semantic Release Process

Visual Regression

Styleguide

generated by kss-node
support twig template
multiple entries
view on
- /dist/index.html
- /dist/[project_name]/index.html

Import styling to a project

run npm install @comicrelief/pattern-lab --save
on local scss file, add @import '~pattern-lab';

(or use includePaths: ['node_modules'] in grunt-sass options configuration)
or copy css file straight to your project

Contribute styling to pattern-lab

Development workflow

Get it up and running in another project

Clone this repository to a directory at the root level of your CR dev, alongside the other project. e.g. git clone https://github.com/comicrelief/pattern-lab ~/cr_root/pattern-lab
Go to the npm root level of the project you want to use it in. E.g. for payin: cd ~/cr_root/payin/web
If that project has a link script, just yarn link-patternlab
Or if it doesn't, npm install npm-link-local --global and then e.g. npm-link-local ~/cr_root/pattern-lab

Either of the last 2 steps creates a symlink in the other project's node_modules, pointing to your local copy of pattern-lab.

Make code changes

it follows same development process: create feature branch -> commit and push changes -> create pull request for code review
run yarn watch to liveload file changes
run yarn build to generate all themes in the styleguide
run yarn build-base to only generate the base theme in the styleguide
run yarn build-cr17 to only generate the cr17 theme in the styleguide
run yarn build-frost to only generate the frost theme in the styleguide
run yarn build-payin to only generate the payin theme in the styleguide
run yarn build-rnd17 to only generate the rnd17 theme in the styleguide
run yarn build-sr18 to only generate the sr18 theme in the styleguide

Dev server

run yarn dev-server or yarn watch
go to http://localhost:1337 to view styleguide

Semantic Release Process

Git commit messages are used to automatically publish a new version of npm package. To achieve this, every commit message should have a type and a message in the format described below.

Travis CI will run a job automatically after PR is merged and analyze all commit messages since last npm release. Then semantic-release plugin will calculate new version according to this result.

To avoid commit loops, version numbers are not committed back to package.json. Versions are listed on GitHub releases and used in the modified package.json published to npm.

Commit messages are expected to be in this format:

<type>(<scope>): <subject>
<BLANK LINE>
<body>
<BLANK LINE>
<footer>

Minimally, only type and subject is required.

Bugfix / patch

When there are no breaking changes or no new features. When we are fixing bugs or styles.

fix: A bug fix

Minor / Feature

When there is a new feature / functionality is added to the library

feat: A new feature

Major / breaking change

When there is a breaking change, we need to extend our commit message and add BREAKING CHANGE: A description of the change to its body. This message can be added to any type of commit. Example:

feat: A new feature

BREAKING CHANGE: A description of the change

Automating commit message format

Commitizen library is added as npm dev dependency and it can be used to generate commit messages by answering a few questions and skipping the ones which are not relavent. Example workflow:

Make code changes in your feature branch
Run git add . to add changed files and get ready to commit
Run yarn commit

This will start an interactive process to build commit message. Simply answer all questions or press Enter to skip.

Repeat and follow rest of the GitHub workflow

CI Pipelines

We are using Concourse CI and Travis CI to run tasks, and Netlify and Cloud Foundry to deploy pattern-lab. When a pull request is created, it triggers a Netlify preview deployment, which is at
```
https://deploy-preview-[PULL_REQUEST_ID]--cr-pattern-lab.netlify.com/
```
Pull request commits and merge also trigger CI visual regression tests as explained below. Output is available at
```
https://ci.services.comicrelief.com/teams/main/pipelines/pattern-lab
```
Visual Regression
- We're using BackstopJS
- CI runs tests on pull request
- Currently the test check against dist/index.html and has the latest changes from master as reference in test/visual/reference.
- See configuration in backstop.json:
```
"url": "dist/index.html",
```
- Run visual regression test locally:
```
yarn backstop-test-local
```
- This will open the pass/fail report from /tests/visual/html_report/index.html in your browser.
- If the test fails, but the changes were inteded you can approve the test and use your changes as the new reference:
```
yarn backstop approve
```
- Run the test locally again and it should pass now.
- Commit the new reference files.