AI React Components: Generate, Test and Review UI Code

AI React components can be generated in seconds and still be wrong in ways that only show up later: a modal that traps no focus, an effect that fetches data twice, a list without stable keys or a form that loses what the user typed. An assistant writes plausible React because it has seen a great deal of it, and much of what it has seen is outdated, sloppy or written for a different version. The skill is not asking for a component. It is specifying the one you need, reviewing what comes back and proving it works with a test and a keyboard.

This guide shows how to prompt for components you can ship, the mistakes that appear most often in generated React, how to test them, how to check accessibility and how to fit the work into a normal review process. It assumes you know the basics of React and TypeScript.

Start with a precise component brief

A vague request such as “make a modal” produces a vague modal. Describe the component like a ticket: its purpose, props and their types, states, behaviour on user actions, the styling approach, the browser and device support and the things that are out of scope. Say which version of React and which tools you use, such as TypeScript, your styling library and your test setup, because the answer changes with each.

Build a React component in TypeScript: Modal.
Props: open (boolean), title (string), onClose (() => void), children.
Behaviour: closes on Escape and on backdrop click; focus moves into the modal
on open and returns to the trigger on close; focus stays inside while open;
page behind is not scrollable while open.
Rules: function component with hooks; no external UI library; plain CSS module;
no dangerouslySetInnerHTML; no any.
Also write tests with React Testing Library covering open, close and focus.
List every assumption you made.

Notice the rules that remove common failures: no any, no raw HTML injection, no library. Ask for a short explanation of the design choices, and for the assumptions list, because it shows where the assistant guessed. If you already have components in the project, paste one as a style reference so that the new code follows your conventions, naming and folder layout. Our guide to AI code generation explains this prompt structure for any language.

Mistakes in AI React components that appear again and again

Generated React fails in a small number of recurring ways. Learn them and review for them first. The React documentation is the best source for the current recommended patterns, and the table below summarises the usual suspects.

Mistake	Symptom	What to ask for instead
Effect used to compute derived state	Extra renders, values that lag behind	Compute during render; use an effect only for synchronising with something outside React
Missing or wrong effect dependencies	Stale values, repeated fetches	Correct dependency list and a cleanup function
Index used as list key	Wrong item state after reorder or delete	Stable unique ids as keys
Everything in one big component	Hard to read and test	Small components with clear props
Premature memoisation everywhere	Clutter without measured benefit	Memoise only after profiling shows a problem
Div with a click handler as a button	No keyboard or screen reader support	A real button or link element
Raw HTML insertion	Cross-site scripting risk	Render text, or sanitise trusted HTML properly
Invented or outdated packages and APIs	Install or runtime errors	Only packages and APIs you confirm in the docs

The first row deserves attention. React’s own guidance, You Might Not Need an Effect, explains that many effects in generated code are unnecessary, and that removing them makes components simpler and faster. Ask the assistant to justify every effect in one sentence, and delete the ones whose justification is “to update state when props change”.

State, data and effects

Decide where state lives before you write it. Local state for a toggle belongs in the component. State shared by two siblings belongs in their parent. State used across the app belongs in a store or a context, and data from a server belongs in a data-fetching layer that handles loading, errors, caching and cancellation. Assistants tend to put everything in local state and fetch inside effects, which works in a demo and breaks in a real app, with race conditions when a user changes the input quickly.

Ask for the three states of any async component explicitly: loading, error and empty, in addition to success. Ask how the component cancels or ignores outdated requests. If your project uses a data library, say which one and paste a working example. For forms, decide whether inputs are controlled and where validation runs, and ask for accessible error messages tied to the field. Review every useEffect, every dependency array and every place that sets state in a loop.

Accessibility is part of the component

Accessibility problems are the most common hidden defects in generated UI. Interactive controls must work with a keyboard, have visible focus, expose a name and role to assistive technology and respect reduced motion preferences. For complex widgets such as dialogs, menus, tabs and comboboxes, follow the patterns in the ARIA Authoring Practices Guide, which describe the expected keyboard behaviour and attributes. Ask the assistant to cite which pattern it follows, and compare its code with the guide.

Prefer native elements when you can: a button, a link, a form control, a native dialog element. They bring behaviour that custom elements need many lines of code to imitate. Test with the keyboard only: tab through, open and close with the Escape key, check that focus never disappears. Our guide to an AI accessibility checker explains what automated tools can find, and what they cannot. Automated scans catch a fraction of issues, so a manual pass is not optional.

Testing generated components

Ask for tests in the same request, and write them against behaviour, not implementation. React Testing Library encourages queries that mirror how users find things: by role, label and visible text. A test that clicks the button named “Open settings” and expects a dialog with the title “Settings” survives refactoring, and a test that inspects internal state does not. The Testing Library documentation shows the approach.

Run the tests, then try to break the component. Rename a prop, remove the effect cleanup or change a key, and see whether a test fails. A test that cannot fail proves nothing. Also test the edge cases the assistant might have ignored: empty data, very long text, rapid clicks, slow network, a user pressing Escape during loading. Our guide to AI-generated tests explains how to avoid tests that only mirror the code, and when not to trust AI-generated code lists the red flags.

Styling, performance and bundle size

State your styling approach and ask the assistant to stick to it. Mixed approaches in one component, such as inline styles, a utility class set and a CSS module together, make code hard to maintain. For layout and responsive behaviour, ask for a mobile-first design and test at narrow widths. Our guide to an AI HTML and CSS generator covers the markup and styles side in more detail.

Performance problems in generated code are usually simple: large lists rendered without virtualisation, expensive work in render, new object and function props created on every render for heavy children and a new dependency added for a trivial task. Profile before optimising. If a component is slow, paste the profile findings and the code and ask for a targeted fix, and see AI code optimization for a safe method. Check what the assistant added to your dependencies, and confirm each package exists, is maintained and is the one you meant, because invented or mistyped package names are a known supply chain risk.

Props, types and component boundaries

Good components have small, honest interfaces. Ask the assistant to define props with precise TypeScript types, to use unions for fixed options instead of loose strings and to avoid optional props that change behaviour in confusing ways. If a component takes ten props, it is probably doing too much, so split it. Check that event handler names describe what happened, such as onClose and onSelect, and that the component does not reach into global state when a prop would do.

Also ask where the component expects to be used. A design system button, a page section and a one-off widget have different needs for flexibility, documentation and testing. Write a short usage example for each component, which doubles as documentation and as a quick check that the interface is pleasant to use. If writing the example feels awkward, the interface needs another pass.

Review process and team habits

Treat generated components like any contribution. Put them through the same linting, type checking, tests and code review as the rest of the project. Ask the author, whether human or assisted, to explain each non-obvious choice. In review, run through a short list: does it do what the ticket says, is it accessible, are effects justified, are types honest, are tests meaningful and does it match the project’s conventions? Our guide to a code review with AI before you merge shows how to use an assistant as a second reviewer without replacing the human one.

Keep a prompt file in the repository with your standing rules: the version, the styling approach, the testing library, the forbidden patterns and a sample component. Paste it at the start of each session, or store it in a project, and your results will become more consistent. Update it when a review finds a recurring problem. Do not paste secrets, tokens or private customer data into prompts.

How Ask Mio helps with React

Ask Mio is one assistant with five modes, and Mio routes each request to a suitable model, so you do not choose one. Chat and Write on the free plan can explain a component, review a snippet and draft tests. The Coding plan adds Code mode and a code execution sandbox for scripts and helper functions, and Research mode with web search and cited sources helps you check the current React documentation, since APIs and recommended patterns change. Your build, browser and keyboard remain the real test.

Memory can store your standing rules and stack so that each new chat starts with them, and a project can keep the reference components and the review checklist. Mio cannot run your application or see your repository unless you paste code. Chats and files stay yours, can be exported or deleted at any time and are not used to train models. Check the live pricing page for current plan details.

Frequently Asked Questions

Can AI write production-ready React components?

It can write a good first version if the brief is precise, but production readiness comes from review. Check effects, types, accessibility, tests and dependencies, run the component in a real browser with a keyboard and merge it only through your normal review. Never ship code that nobody read.

Why does generated React code use useEffect so much?

Because much of the code the assistant learned from overuses effects. Many of them are unnecessary, since derived values can be computed during render. Ask the assistant to justify each effect, and remove those that only copy props into state or react to state changes that an event handler could handle.

How do I check that a generated component is accessible?

Use native elements where possible, follow the matching pattern in the ARIA Authoring Practices Guide, test with the keyboard only, check focus handling and run an automated scan. Scans find only part of the problems, so also test with a screen reader if you can.

Can I trust the packages an assistant suggests?

Not without checking. Assistants sometimes suggest packages that do not exist, are abandoned or have names close to real ones. Confirm each in the official registry and documentation, check maintenance and licence and prefer fewer dependencies. Install from your own list of approved packages when you can.

Which Ask Mio plan helps with front-end coding?

The free plan includes Chat and Write for explanations, reviews and test drafts. The Coding plan adds Code mode and a sandbox, and paid plans add Research with cited sources, uploads and memory for your stack rules. Check the live pricing page for current points and limits before choosing.

The Bottom Line

AI React components save time when you give a precise brief, ban the usual bad patterns, demand tests and accessibility and review effects, types and dependencies like any other pull request. Keep a standing rules file, check against the official documentation and let your keyboard and your tests be the final judge. You can start on the free plan and compare options on the Ask Mio pricing page.