chore(ui): add ui guide for developers (#24418)

* chore(ui): add ui guide for developers

* address comment

openmetadata-ui/src/main/resources/ui/DEVELOPER_HANDBOOK.md

@@ -0,0 +1,171 @@
+# OpenMetadata UI Developer Handbook
+
+## 1. Folder Structure
+
+```
+@src/
+│
+├── assets/                # Static files (images, fonts, icons, etc.)
+├── components/            # Reusable UI components (buttons, modals, etc.)
+│   └── [ComponentName]/
+│       ├── index.tsx
+│       ├── [ComponentName].tsx
+│       ├── [ComponentName].test.tsx
+│       ├── [ComponentName].style.less
+│       └── [ComponentName].types.ts   # (if needed, see below)
+├── constants/             # App-wide constants and enums
+├── context/               # React context providers
+├── hooks/                 # Custom React hooks
+├── interface/             # TypeScript interfaces and types (shared)
+├── pages/                 # Top-level pages/views (mapped to routes)
+│   └── [PageName]/
+│       ├── index.tsx
+│       ├── [PageName].tsx
+│       ├── [PageName].test.tsx
+│       ├── [PageName].style.less
+│       └── [PageName].types.ts   # (if needed)
+├── routes/                # Route definitions and helpers
+├── store/                 # State management (Redux, Zustand, etc.)
+├── api/                   # API service functions and clients
+├── utils/                 # Utility/helper functions
+├── styles/                # Global styles, variables, mixins (LESS)
+├── App.tsx                # Main app component
+├── index.tsx              # Entry point
+└── ...                    # Other config files, setup, etc.
+```
+
+## 2. File Naming Conventions
+
+- Use PascalCase for components, pages, and their folders: `UserProfile`, `UserProfile.tsx`
+- Use camelCase for hooks and utility functions: `useFetchData.ts`, `formatDate.ts`
+- Use UPPER_CASE for constants: `API_URL`
+- Test files: `[ComponentName].test.tsx` or `[util].test.ts`
+- Styles: `[ComponentName].style.less` for component-scoped styles
+- Types: `[ComponentName].types.ts` for component-specific types (see below)
+
+## 3. Component Structure
+
+Each component/page should have its own folder containing:
+- Main component file (`.tsx`)
+- Test file (`.test.tsx`)
+- Styles (`.style.less`)
+- Index file for clean imports
+- Types file (`.types.ts`) if types are complex or reused
+
+Example:
+```
+components/
+  Button/
+    Button.tsx
+    Button.test.tsx
+    Button.style.less
+    Button.types.ts
+    index.ts
+```
+
+## 4. Component-Specific Types
+
+- For simple or small components, define types/interfaces at the top of the component file.
+- For complex components or when types are reused elsewhere, create a separate file:
+  - `[ComponentName].types.ts`
+- **Rule of Thumb:**
+  - If the type is only used in one file and is simple, keep it in the same file.
+  - If the type is reused or complex, use a separate `.types.ts` file.
+
+## 5. API Layer
+
+- All API calls go in `@src/api/`
+- Group by resource (e.g., `userApi.ts`, `projectApi.ts`)
+- Use TypeScript interfaces from `@src/interface/`
+- Keep API logic separate from UI logic
+
+## 6. State Management
+
+- Use `@src/store/` for global state (Redux, Zustand, etc.)
+- Organize by feature/domain
+- Keep actions, reducers, and selectors together
+
+## 7. Hooks
+
+- Place all custom hooks in `@src/hooks/`
+- Prefix with `use` (e.g., `useAuth.ts`)
+- Keep hooks generic and reusable
+
+## 8. Interfaces & Types
+
+- All shared types/interfaces go in `@src/interface/`
+- Group by domain or feature
+- Import types from here in components, API, and store
+
+## 9. Testing
+
+- Use Jest + React Testing Library
+- Test files live next to the code they test
+- Cover components, hooks, utils, and API logic
+
+## 10. Routing
+
+- Define all routes in `@src/routes/`
+- Use a central file for route paths and lazy loading
+
+## 11. Assets
+
+- Place images, SVGs, fonts, etc. in `@src/assets/`
+- Organize by type or feature
+
+## 12. Styles
+
+- Use LESS style for component styles (`.style.less`)
+- Place global styles, variables, and mixins in `@src/styles/` as `.less` files
+
+## 13. UI Library (MUI) and Icons (@untitledui/icons)
+
+- Primary UI library: Material UI (MUI v5).
+- Icon source: @untitledui/icons.
+
+Recommended project layout for MUI and icons:
+- Theme and providers:
+  - @src/styles/theme.ts         -> createTheme, overrides, palette, typography
+  - @src/styles/mui-overrides.less -> LESS file for any global CSS overrides (kept minimal)
+  - App.tsx should wrap the app with MUI ThemeProvider and CssBaseline:
+    - Place providers at top-level (App.tsx or @src/context/Providers.tsx).
+- Component-level usage:
+  - Prefer MUI components for common primitives (Button, TextField, Menu, Dialog).
+  - Create small app-specific wrappers in @src/components/ui/ for commonly used variants:
+    - e.g., @src/components/ui/Button/ (wrap MUI Button to apply project defaults)
+- Styling with LESS styles and MUI:
+  - Prefer MUI theming and the `sx` prop for dynamic styling (colors, spacing).
+  - Use `.style.less` for component-specific static styles and layout that are easier in LESS.
+  - Avoid conflicting global CSS rules; favour scoped className+style.less together with `sx` for theme-aware overrides.
+  - For global MUI component overrides, use the theme `components` key in createTheme (not global CSS).
+- Icons:
+  - Import icons directly to keep bundle size small. Example:
+    - import { IconName } from '@untitledui/icons';
+  - Create a single re-export file for commonly used icons:
+    - @src/assets/icons/index.ts — re-export the subset of icons used across app to centralize changes.
+  - For rarely used icons, import directly where needed to enable tree-shaking.
+  - Wrap icons in an Icon component if you need consistent sizing, color, or additional behavior:
+    - @src/components/ui/Icon/Icon.tsx
+- Accessibility and ARIA:
+  - Use MUI's accessible primitives (IconButton with aria-label, role, etc.).
+  - Ensure icons used as interactive elements have accessible names or aria-hidden when decorative.
+- Testing with MUI:
+  - Provide a test render helper that wraps components with ThemeProvider and any required context:
+    - @src/test/utils/renderWithProviders.tsx
+  - Mock or configure MUI components where needed in Jest for stable snapshots.
+- Performance & bundle:
+  - Prefer named imports to maintain tree-shaking for MUI and icon packages.
+  - Keep the icon re-export file limited to used icons; avoid exporting entire icon packs.
+
+## 14. General Rules
+
+- Keep files small and focused
+- Prefer composition over inheritance
+- Use TypeScript everywhere
+- Write clear, descriptive comments and JSDoc where needed
+- Use absolute imports from `@src/` (configure `tsconfig.json` paths)
+- Keep third-party code and wrappers in a separate folder if needed
+
+---
+
+This handbook ensures a clean, scalable, and consistent codebase for all developers.

openmetadata-ui/src/main/resources/ui/README.md

@@ -61,6 +61,27 @@ Once the node and yarn are installed in the system, you can perform the followin
 
 **Step 3**: Visit [localhost:3000](http://localhost:3000/) to access the OpenMetadata UI.
 
+## Developer instructions
+
+This directory contains UI resources and the developer handbook for the OpenMetadata frontend.
+
+Quick links
+- Developer handbook: [DEVELOPER_HANDBOOK.md](./DEVELOPER_HANDBOOK.md)
+  - Purpose: folder/file conventions, styling (LESS), MUI + @untitledui/icons usage, testing rules, and more.
+
+Getting started (for a new developer)
+1. Open this folder in your editor.
+2. Read DEVELOPER_HANDBOOK.md for coding standards and folder structure.
+3. Key technologies:
+   - React + TypeScript
+   - MUI (v5) as primary UI library
+   - @untitledui/icons for icons
+   - LESS (.module.less) for component styles
+   - Jest + React Testing Library for tests
+4. Use absolute imports from @src/ (see tsconfig paths).
+
+If anything in the handbook is unclear or missing, open a PR with suggested edits under this directory so the team can review and keep the guide up to date.
+
 ## How to Add Language Support
 
 To add support for a new language in our internationalization setup using `react-i18next` and `i18next`, please follow the steps below: