mattermost/webapp/platform/CLAUDE.OPTIONAL.md

CLAUDE: webapp/platform/

Purpose

• Shared packages consumed by every Mattermost web experience (Channels, Boards, Playbooks, plugins).
• Changes here affect multiple products—coordinate across teams before merging.

Packages

Package	Directory	Purpose
@mattermost/types	types/	TypeScript type definitions
@mattermost/client	client/	REST and WebSocket API client
@mattermost/components	components/	Shared React components
@mattermost/shared	shared/	Cross-product components and utilities for the web app and plugins (e.g. Button, WithTooltip). Prefer these over rolling your own
@mattermost/eslint-plugin	eslint-plugin/	Custom ESLint rules

Workspace Basics

• Each subpackage is its own npm workspace with independent package.json, tests, and build scripts.
• Run commands with npm run <script> --workspace=@mattermost/<pkg> (e.g., @mattermost/client).
• Versioning follows the monorepo; publishable artifacts come from CI pipelines.

Import Convention

Always import using the full package name:

// CORRECT
import {Client4} from '@mattermost/client';
// INCORRECT - never use relative paths
import Client4 from '../platform/client/src/client4';

Build Relationship

Platform packages are automatically built on npm install via postinstall hook. Build order: types → client/components.

Note: When developing in channels, changes in platform packages may need a rebuild if not using a watcher that supports them.

Adding Dependencies

When adding dependencies to platform packages:

npm add package-name --workspace=@mattermost/client

Expectations

• Follow webapp/STYLE_GUIDE.md.
• Maintain 100% TypeScript coverage; no any.
• Update downstream consumers when making breaking changes.