# Ultracite for Junie Use Ultracite with Junie when you want JetBrains-assisted coding to follow a committed project contract instead of relying on per-user IDE habits. It is particularly helpful for typed application codebases where consistency and safe refactors matter. ## Setup details These values come from the same data Ultracite uses when it creates or updates Junie instructions, so the page matches what actually gets written into the repo. ### AGENTS.md Run `npx ultracite@latest init --agents junie` and Ultracite will update this file for the default setup. ### Configuration file AGENTS.md Ultracite writes to this exact file when you initialize or update the agent integration. ### Write mode Append to existing instructions Existing instructions stay in place and Ultracite appends its rules where the agent expects them. ### Header handling Writes rules directly The generated file starts directly with Ultracite rules and skips an extra heading block. ### Hook support No separate hook file Junie does not use a separate hook configuration in Ultracite. ## Files Ultracite writes for Junie This preview shows the exact default file content Ultracite writes for Junie when you use the standard Biome setup. ### Markdown AGENTS.md ``` # Ultracite Code Standards This project uses **Ultracite**, a zero-config preset that enforces strict code quality standards through automated formatting and linting. ## Quick Reference - **Format code**: `npx ultracite fix` - **Check for issues**: `npx ultracite check` - **Diagnose setup**: `npx ultracite doctor` Biome (the underlying engine) provides robust linting and formatting. Most issues are automatically fixable. --- ## Core Principles Write code that is **accessible, performant, type-safe, and maintainable**. Focus on clarity and explicit intent over brevity. ### Type Safety & Explicitness - Use explicit types for function parameters and return values when they enhance clarity - Prefer `unknown` over `any` when the type is genuinely unknown - Use const assertions (`as const`) for immutable values and literal types - Leverage TypeScript's type narrowing instead of type assertions - Use meaningful variable names instead of magic numbers - extract constants with descriptive names ### Modern JavaScript/TypeScript - Use arrow functions for callbacks and short functions - Prefer `for...of` loops over `.forEach()` and indexed `for` loops - Use optional chaining (`?.`) and nullish coalescing (`??`) for safer property access - Prefer template literals over string concatenation - Use destructuring for object and array assignments - Use `const` by default, `let` only when reassignment is needed, never `var` ### Async & Promises - Always `await` promises in async functions - don't forget to use the return value - Use `async/await` syntax instead of promise chains for better readability - Handle errors appropriately in async code with try-catch blocks - Don't use async functions as Promise executors ### React & JSX - Use function components over class components - Call hooks at the top level only, never conditionally - Specify all dependencies in hook dependency arrays correctly - Use the `key` prop for elements in iterables (prefer unique IDs over array indices) - Nest children between opening and closing tags instead of passing as props - Don't define components inside other components - Use semantic HTML and ARIA attributes for accessibility: - Provide meaningful alt text for images - Use proper heading hierarchy - Add labels for form inputs - Include keyboard event handlers alongside mouse events - Use semantic elements (`