This content originally appeared on Bits and Pieces - Medium and was authored by Ashan Fernando
Build modular, scalable, and maintainable applications with these JavaScript tools.
Modern software development is shifting towards composability — the idea that small, independent pieces of code can be combined to build scalable applications. This approach simplifies maintenance, speeds up development, and improves reusability. Instead of working with large, complex codebases, developers can mix and match well-defined components that work together.
JavaScript has a strong ecosystem of tools designed to support composability across UI components, APIs and data management. This article explores five JavaScript tools and platforms that help break down complexity and promote composable software development.
1. Bit — A Platform for Reusable Components
Bit is a complete platform for developing, sharing, and managing independent components. Instead of keeping everything in a single monolithic repository, Bit allows developers to work with self-contained components — UI elements, utilities, or even entire services — that can be versioned and used across different projects.
Why It’s Useful
- Component Isolation — Each component can be developed and tested separately.
- Version Control for Components — Updates to a component don’t require modifying an entire codebase.
- Easier Code Sharing — Teams can collaborate without dealing with tightly coupled dependencies.
Example: Creating a Shared UI Component
bit create react ui/button
bit add src/components/Button.js --main src/components/Button.js
bit tag --message "Initial commit"
bit export my-org.ui/button
Once created, the component can be exported to Bit Platform.
This allows multiple projects to install and use the same ui/button component across repositories, consuming the component from Bit Platform and ensuring consistency without duplicating code.
Why It Helps
Bit makes component reuse more practical. Instead of manually copying code across projects or creating a bulky npm package, you can create a collection of shared components (scope) in a Bit platform where each component can be selected independently from the consumer project.
2. Zod — Composable Type-Safe Schema Validation Without Extra Code
Zod is a TypeScript-first schema validation library that allows you to define reusable, composable data structures. You can use one schema for both instead of writing separate TypeScript interfaces and runtime validation logic.
Why It’s Useful
- Composable Schemas — Combine smaller schemas into complex structures.
- Single Source of Truth — Ensures runtime validation matches TypeScript types.
- Structured Error Handling — Catches validation errors early.
Example: Composing JSON Objects
Instead of defining a large, monolithic schema, you can compose smaller schemas into a reusable structure:
import { z } from "zod";
// Define reusable schemas
const AddressSchema = z.object({
street: z.string().min(3),
city: z.string(),
postalCode: z.string().length(5),
country: z.string(),
});
const UserSchema = z.object({
id: z.number().positive(),
name: z.string().min(2),
email: z.string().email(),
address: AddressSchema, // Composing schemas
});
// Validate a user object
const user = {
id: 1,
name: "Alice",
email: "alice@example.com",
address: { street: "123 Main St", city: "NY", postalCode: "10001", country: "USA" },
};
const result = UserSchema.safeParse(user);
console.log(result.success ? "Valid user" : result.error.format());Why It Helps
Zod keeps data validation structured and reusable, making it a great choice for ensuring consistent data across APIs, forms, and databases.
3. tRPC — Composable API Development Without Boilerplate
tRPC enables type-safe API development without the overhead of REST or GraphQL. Instead of manually defining API contracts, clients and servers share the same types, ensuring seamless data flow and reducing errors.
Why It’s Useful
- Composable API Procedures — Group related API logic into reusable modules.
- End-to-End Type Safety — Clients and servers always stay in sync.
- Minimal Setup — No need for REST endpoints or GraphQL resolvers.
Example: Composable API Modules
Instead of defining APIs in a single file, you can break them into reusable procedures.
import { initTRPC } from "@trpc/server";
import { z } from "zod";
const t = initTRPC.create();
// Define a composable "User API" module
export const userRouter = t.router({
getUser: t.procedure.input(z.string()).query(({ input }) => ({
id: input,
name: "Alice",
})),
});
// Define a "Posts API" module separately
export const postRouter = t.router({
getPosts: t.procedure.query(() => [
{ id: 1, title: "Hello World" },
{ id: 2, title: "tRPC is great!" },
]),
});
// Compose both routers into a single appRouter
export const appRouter = t.router({
user: userRouter,
posts: postRouter,
});
export type AppRouter = typeof appRouter;Now, clients can call modular API procedures without dealing with endpoints:
const user = await trpc.user.getUser.query("123");
const posts = await trpc.posts.getPosts.query();Why It Helps
By organizing API logic into reusable modules, tRPC makes backend development more modular and maintainable.
4. TanStack Query — Composable Data Fetching and State Management
TanStack Query (formerly React Query) simplifies data fetching, caching, and synchronization in JavaScript applications. It separates data logic from UI components, making queries more reusable and composable.
Why It’s Useful
- Encapsulated Query Logic — Define reusable hooks for fetching data.
- Automatic Caching — Prevents redundant API calls.
- Background Data Synchronization — Keeps UI up to date.
Example: Composable Query Hooks
Instead of handling API calls in each component, define reusable query hooks:
import { useQuery } from "@tanstack/react-query";
// Define a reusable query hook
const useUser = (id: string) =>
useQuery(["user", id], async () => {
const res = await fetch(`/api/user/${id}`);
return res.json();
});
// Define another query for posts
const usePosts = () =>
useQuery(["posts"], async () => {
const res = await fetch(`/api/posts`);
return res.json();
});
// Use the composable query hooks in components
const Profile = ({ id }) => {
const { data: user, isLoading: userLoading } = useUser(id);
const { data: posts, isLoading: postsLoading } = usePosts();
if (userLoading || postsLoading) return <p>Loading...</p>;
return (
<div>
<h1>{user.name}</h1>
<h2>Posts</h2>
<ul>{posts.map((post) => <li key={post.id}>{post.title}</li>)}</ul>
</div>
);
};Why It Helps
TanStack Query makes state management composable and efficient by separating data-fetching logic into reusable hooks.
5. Radix UI — Composable, Accessible UI Components
Radix UI is a headless component library that provides unstyled, accessible UI primitives. Instead of enforcing styles, it separates logic from presentation, making it easy to integrate into any design system.
Why It’s a Better Fit for Composability
- Composable UI Primitives — Mix and match reusable components.
- Headless Architecture — Decouples behavior from styles.
- Keyboard & Accessibility Features — Built-in ARIA compliance.
Example: Composing UI Components with Radix UI
Here’s how you can create a reusable modal dialog that can be used anywhere:
import * as Dialog from "@radix-ui/react-dialog";
// Define a reusable Modal component
export function Modal({ title, children, triggerText }) {
return (
<Dialog.Root>
<Dialog.Trigger>{triggerText}</Dialog.Trigger>
<Dialog.Portal>
<Dialog.Overlay className="modal-overlay" />
<Dialog.Content className="modal-content">
<Dialog.Title>{title}</Dialog.Title>
{children}
<Dialog.Close>Close</Dialog.Close>
</Dialog.Content>
</Dialog.Portal>
</Dialog.Root>
);
}
// Use the composable Modal in different places
export function App() {
return (
<div>
<Modal title="User Settings" triggerText="Open Settings">
<p>Change your user preferences here.</p>
</Modal>
<Modal title="Delete Account" triggerText="Delete">
<p>Are you sure you want to delete your account?</p>
</Modal>
</div>
);
}
Why It Helps
Radix UI allows you to build reusable UI components while maintaining full control over styling, making it a great fit for component-driven development.
Following is a composable design system built using Radix UI. It also uses the Bit platform to make it a reusable design system across various projects.
You can use it to directly start with your composable web app development.
Final Thoughts
Each of these tools supports composability by making code more modular, reusable, and maintainable. Whether you’re working on UI components, APIs, or state management, composability helps reduce complexity and improve scalability.
By incorporating these tools into your development workflow, you can build applications that are easier to manage, extend, and collaborate on.
Thanks for reading !!! Cheers !!!
Learn More
- Composable Software Architectures are Trending: Here’s Why
- Composable Cloudflare Architecture: A Guide
- AI Coding Assistants, Starter Templates, and More: A Guide to Working less
- Building a Fast and Efficient Composable App using React and Rspack
5 JavaScript Tools That Make Composability Easy was originally published in Bits and Pieces on Medium, where people are continuing the conversation by highlighting and responding to this story.
This content originally appeared on Bits and Pieces - Medium and was authored by Ashan Fernando
Ashan Fernando | Sciencx (2025-02-12T14:37:41+00:00) 5 JavaScript Tools That Make Composability Easy. Retrieved from https://www.scien.cx/2025/02/12/5-javascript-tools-that-make-composability-easy/
Please log in to upload a file.
There are no updates yet.
Click the Upload button above to add an update.