For Developers

Maintaining Canvas Kit

If you're a Canvas Kit core maintainer, this doc is for you! Consider this a field guide to help you maintain Canvas Kit with confidence. If you see some information that's unclear, incomplete, or incorrect, please update this doc to help your future self and others. Thanks for maintaining Canvas Kit!

Branches

We maintain three major versions of Canvas Kit at any given time: the previous major, the current major, and the next major version. These versions live in four branches:

  • support - the previous major version - patches only, no new features or breaking changes
  • master - the current major version - patches and small updates only
  • prerelease/minor - the current major version - new features are added here
  • prerelease/major - the next major version - patches, new features, and major breaking changes

GitHub Actions

We use GitHub Actions to automate our workflows and CI / CD processes. You can view all our workflows here.

Forward Merge Workflow

Forward merges ensure that changes made in lower-versioned branches are forwarded to higher-versioned branches. So for example, if a bug is patched in the support branch, forward merging propogates the fix so it's available in master, prerelease/minor and prerelease/major branches. This workflow is fully automated, which reduces opportunities for error.

The forward merge workflow runs on support, master, and prerelease/minor branches. Forward merges for support and master run automatically when a release commit is merged to that branch. Every release commit starts with chore: Release, and that's how the forward merge workflow identifies them. Forward merges will run on every merge to prerelease/minor regardless of the commit message.

Run Forward Merge?BranchCommit Message
supportchore: Release v6.8.14 [skip release]
⛔️supportfix: Remove unused props
masterchore: Release v7.3.0 [skip release]
⛔️masterfix: Update Popup types
prerelease/minorfeat: Add new Layout components

If the forward merge workflow fails and cannot automatically merge the update to the next branch, it will generate a PR with instructions on how to handle the forward merge manually. For a more in-depth review, view the workflow source code.

Release Minor Workflow

The release minor workflow is initated manually and begins the process for minor releases. It checks out the prerelease/minor branch and pushes any commits not in master to the master branch. It does not run any tests or validations as all the commits have been verified by the previous workflows. Once prerelease/minor is merged to master, it will trigger the release workflow which will publish a new version of Canvas Kit.

This workflow will only fail if there are commits in master that are not included in prerelease/minor. You can verify that here. In that case, you'll need to foward merge any commits in master to prerelease/minor. For a more in-depth review of the workflow, view the source code.

Release Workflow

The release workflow is initiated automatically and runs the release process for all Canvas Kit releases (major, minor, and patch) on the master and support branches. This workflow will only run if:

  • The commit message does not contain [skip release]
  • OR the workflow was manually triggered and has a version string

At a high-level, this workflow will:

  • checkout the repository
  • install dependencies (if they are not already cached)
  • run yarn bump to craete a commit and a git tag
  • bump package versions
  • generate a changeset
  • update the changelog
  • build Storybook
  • publish to npm
  • create a GitHub release
  • publish Storybook
  • update Chromatic baseline
  • notify Slack

For a more in-depth review of the workflow, view the source code

Canary Workflow

The canary workflow are initiated automatically when a commit is merged to prerelease/minor or prerelease/major. For a more in-depth review of the workflow, view the source code.

Releases

Patch Releases

Patch releases in the support and master branches go out automatically once the pull request is merged. These releases use the release workflow to publish updates automatically.

Minor Releases

Canvas Kit minor releases occur every three weeks. They are initiated manually by a maintainer with the release minor workflow. Before you initiate a minor release, all branches up to prerelease/minor need to be forward merged. Check all of the following to make sure there are no commits listed:

If there are any commits listed, run the forward merge for the branch that isn't merged forward (support, master, or prerelease/minor). It is safe to run this job even if there are no changes since the job will recognize no change and bail.

Major Releases

Canvas Kit major releases occur every six months. They are manual and performed by a maintainer. The process is similar to minor releases, except the addition of the support branch. All branches have to be forward merged. Check all of the following to make sure there are no commits listed:

  • Compare master with support
  • Compareprerelease/minor with master
  • Compareprerelease/major with prerelease/minor

If there are any commits listed, run the forward merge for the branch that isn't merged forward (support, master, or prerelease/minor). It is safe to run this job even if there are no changes since the job will recognize no change and bail.

We'll be using the terms previous major, current major, and next major in the context of versions before the release process is complete. For example, if support is pointing to v4, master to v5 and prerelease/major to v6, we need to update these pointers. After these steps are completed, the following will happen:

  • support: v4 -> v5
  • master: v5 -> v6
  • prerelease/minor: v5 -> v6
  • prerelease/major: v6 -> v7

Before starting the next steps, we need to disable some CI jobs (Disabling Workflow Docs).

These jobs will only cause problems during the release cycle. We will enable them when we're done.

Locally, make sure to fetch upstream.

git fetch upstream
  1. Update support to point to the current major version master is currently pointing to. This effectively moves the HEAD pointer of the support branch to the same HEAD of master

    git checkout master
    git pull upstream master
    git push upstream master:support

    Normally, this would trigger a release job, but we've disabled the job and there's nothing to release anyway.

  2. Re-enable the Release job (Enable Workflow Docs)

  3. Update master to point to the next major release prerelease/major is currently pointing to. This step produces the actual release, including a Slack message.

    git checkout prerelease/major
    git pull upstream prerelease/major
    git push upstream prerelease/major:master

    This will trigger the release workflow. Up to this point, prerelease/major has been creating canary jobs. This will trigger the actual release. We must wait for this job to finish. The job will be running against master. The CI job will run lerna bump and push that commit back onto the master branch which will include the update to lerna.json that we need in the next step.

    Note: If something went wrong and a version is incorrect, you can cancel this release workflow run and manually run it with a version override. For example, for the v8.0.0 release, a lerna bump command chose v8.0.0 for a release version on a patch update and we had to remove this release from npm. According to npm's release policy, they take down the release from npm, but the version string can never be used again, so we the actual v8 release was 8.0.1

  4. We need to wait for the release workflow job to finish and the slack message be announced. Once the previous step is completed, we need to update prerelease/minor and prerelease/major to point to the current HEAD of master (which should now contain the next major version release commit).

    git checkout master
    git pull upstream master
    git push upstream master:prerelease/minor
    git push upstream master:prerelease/major
  5. Re-enable the Canary and forward-merge workflows (Enable Workflow Docs)

  6. 🎉

Canary Releases

Canary releases use the canary workflow to automatically publish test versions of Canvas Kit. While these releases can be unstable, they are useful for external testing or allowing teams to experiment with new features or fixes before a stable release is available. These releases only run on prerelease/minor and prerelease/major branches.

Prerelease Minor Canaries

Canary releases on the prerelease/minor branch go out automatically once the pull request is merged. The major version will be appended with -next.{commit-count}, where commit-count is the number of commits since the last release tag. So for example, a V7 canary would look something like this: 7.3.0-next.3.

Prerelease Major Canaries

Canary releases on the prerelease/major branch go out automatically once the pull request is merged. The major version will be appended with -alpha.{build-number}-next.{commit-count}, where build-number is the GitHub build identifier, and commit-count is the number of commits since the last release tag. So for example, a V8 canary would look something like this: 8.0.0-alpha.127-next.4.

Codemods

We use codemods to reduce friction for consumers as they make changes and do upgrades. Codemods are accompany major version releases since v5, and can also be released in minor releases if users want to apply some changes sooner.

Add a New Codemod

Adding a new codemod is pretty straightforward, but this guide will make sure you don't miss any steps along the way.

First, you need to add a new command to the root CLI. For this example, we'll pretend you're adding a new v10 codemod.

Initial Setup

// modules/codemod/lib/index.js
.command('v10 [path]', chalk.gray('Canvas Kit v9 > v10 upgrade transform'), yargs => {
yargs.positional('path', {
type: 'string',
default: '.',
describe: chalk.gray('The path to execute the transform in (recursively).'),
});
})

Next, you'll want to add new v10 files and directories.

# add code and spec directories
mkdir modules/codemod/v10 modules/codemod/spec
# add code files
touch modules/codemod/v10/index.ts modules/codemod/v10/__example__.ts
## add spec files
touch modules/codemod/v10/spec/__example__.spec.ts modules/codemod/v10/spec/expectTransformFactory.spec.ts

Add the Codemod

Now you can add your first (placeholder) codemod.

// modules/codemod/v10/__example__.ts
import {Transform} from 'jscodeshift';
// placeholder codemod
const transform: Transform = (file, api) => {
const j = api.jscodeshift;
const root = j(file.source);
return root.toSource();
};
export default transform;

And add a codemod runner:

// modules/codemod/v10/index.ts
import {Transform} from 'jscodeshift';
// TODO: Remove this
import placeholderCodemod from './__example__';
const transform: Transform = (file, api, options) => {
// These will run in order. If your transform depends on others, place yours after dependent transforms
const fixes = [
// TODO: Remove this
placeholderCodemod,
// add codemods here
];
return fixes.reduce((source, fix) => fix({...file, source}, api, options) as string, file.source);
};
export default transform;

Add Tests

Now you're ready to add your tests. First, we'll add this test factory to make your tests easier to write.

// modules/codemod/v10/spec/expectTransformFactory.spec.ts
import {runInlineTest} from 'jscodeshift/dist/testUtils';
export const expectTransformFactory = (fn: Function) => (
input: string,
expected: string,
options?: Record<string, any>
) => {
return runInlineTest(fn, options, {source: input}, expected, {parser: 'tsx'});
};
// modules/codemod/v10/spec/__example__.spec.ts
import {expectTransformFactory} from './expectTransformFactory';
import transform from '../__remove_this__';
const expectTransform = expectTransformFactory(transform);
describe('Example Codemod', () => {
it('should not modify the code', () => {
const input = "const foo = 'bar';";
const expected = "const foo = 'bar';";
expectTransform(input, expected);
});
});

And that's it! You're done. Stage your changes, commit, and push up a PR.

Deprecations

We add the @deprecated JSDoc tag to code we plan to remove in a future major release. This signals consumers to migrate to a more stable alternative before the deprecated code is removed.

Add the @deprecated tag to the JSDoc comment directly above all exported declarations you wish to deprecate. Create a new JSDoc comment if one doesn't already exist.

/**
* ...existing JSDoc comment, if present...
*
* @deprecated ⚠️ ${Deprecated Name} has been deprecated and will be removed in a future major release. ${Provide a migration strategy}
*/
export...

The provided migration strategy can take on any form as long as it gives the consumer a path forward once the deprecated code is removed.

For example, we'll deprecate a component in our Main package before replacing it with an updated version of the component in our Preview or Labs packages. Note the inclusion of package names (Main/Preview/Labs) for disambiguation as well as the optional Storybook link to the updated component.

/**
* @deprecated ⚠️ Status Indicator in Main has been deprecated and will be removed in a future major release. Please use [Status Indicator in Preview](https://workday.github.io/canvas-kit/?path=/docs/preview-status-indicator--basic) instead.
*/
export class StatusIndicator...

Here's an example of a deprecated utility function.

/**
* @deprecated ⚠️ `subModelHook` has been deprecated and will be removed in a future major release. Please use `createSubModelElemPropsHook` instead.
*/
export const subModelHook...

You may share the same @deprecation note for multiple deprecations related to the same component.

/**
* @deprecated ⚠️ Status Indicator in Main has been deprecated and will be removed in a future major release. Please use [Status Indicator in Preview](https://workday.github.io/canvas-kit/?path=/docs/preview-status-indicator--basic) instead.
*/
export enum StatusIndicatorType...
/**
* @deprecated ⚠️ Status Indicator in Main has been deprecated and will be removed in a future major release. Please use [Status Indicator in Preview](https://workday.github.io/canvas-kit/?path=/docs/preview-status-indicator--basic) instead.
*/
export interface StatusIndicatorProps...
/**
* @deprecated ⚠️ Status Indicator in Main has been deprecated and will be removed in a future major release. Please use [Status Indicator in Preview](https://workday.github.io/canvas-kit/?path=/docs/preview-status-indicator--basic) instead.
*/
export class StatusIndicator...

Finally, be sure to notify users of the deprecation in the corresponding Upgrade Guide MDX.

## Deprecations
...
### ${Deprecated Name}
**PR:** [#${PR number where the deprecation took place}](https://github.com/Workday/canvas-kit/pull/${PR number})
We've deprecated ${Deprecated Name} ${Optional: Include package name to disambiguate (e.g., "from Labs")} ${Provide a
migration strategy}

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