React Super Switch

A small React utility component for deterministic, readable, and safe conditional rendering.

react-super-switch guarantees that exactly one view is rendered from a set of mutually exclusive options, even when conditions are complex, unrelated, or derived from business logic.

Bundle size

react-super-switch is designed to be extremely lightweight.

• ESM bundle: ~10 KB raw / <= 1KB minified + gzipped
• CJS bundle: ~7.2 KB raw / <= 1KB minified + gzipped
• Dependencies: none

Only the selected bundle format is included in your production build; TypeScript types and other metadata are not shipped to users.

Why React Super Switch exists

Conditional rendering in React often starts simple and slowly becomes hard to reason about.

The common problem

return (
  <>
    {caseA && <ViewA />}
    {caseB && <ViewB />}
    {caseC && <ViewC />}
    {caseD && <ViewD />}
  </>
);

This pattern has several issues:

• Multiple views can accidentally render at the same time
• Ordering and priority are implicit and fragile
• Negating conditions quickly becomes unreadable
• Refactors are risky and hard to review
• React Fragments are often required just to make JSX valid
• React does not support switch or if / else directly in JSX

As business logic grows, correctness and readability degrade fast.

The solution

React Super Switch introduces a declarative, safe alternative:

• Exactly one option is rendered
• Conditions are clearly scoped
• Priority is explicit (optional)
• A default fallback can be defined

Invalid configurations fail loudly during development

Installation

npm install react-super-switch

Requirements

• React 17 or newer
• react and react-dom are peer dependencies
• No runtime Node.js requirement for consumers

Basic usage

import { SuperSwitch, Option } from "react-super-switch";

The package exposes named exports only.

Example

Before

return (
  <>
    {businessCaseA && <ViewA />}
    {businessCaseB && <ViewB />}
    {businessCaseC && <ViewC />}
    {businessCaseD && <ViewD />}
  </>
);

After

return (
  <SuperSwitch>
    <Option condition={businessCaseA}>
      <ViewA />
    </Option>

    <Option condition={businessCaseB}>
      <ViewB />
    </Option>

    <Option condition={businessCaseC} default>
      <ViewC />
    </Option>

    <Option condition={businessCaseD}>
      <ViewD />
    </Option>
  </SuperSwitch>
);

Only one <Option /> will ever render.

Core concepts

<SuperSwitch />

The parent component that evaluates all <Option /> children and decides which one to render.

<SuperSwitch mode="fcfs | priority">{options}</SuperSwitch>

Prop	Type	Default	Description
mode	"fcfs" or "priority"	"fcfs"	Determines how options are evaluated
optional	boolean	false	Allows the switch to render nothing when all Option conditions are falsy.

<Option />

Represents a single renderable branch.

<Option condition={boolean} priority={number} default>
  {children}
</Option>

Prop	Type	Required	Description
condition	boolean	❌	Whether this option is eligible
priority	number	❌	Ordering hint (lower = higher priority)
data-testid	string	❌	A unique identifier for testing purposes
default	boolean	❌	Fallback option if no conditions match
children	ReactNode	✅	Rendered when this option is selected

Evaluation modes

1. fcfs (First-Come-First-Served) — default

Options are evaluated in JSX order.

• The first option with a truthy condition wins
• If no conditions match, the first default option is rendered
• priority is ignored

<SuperSwitch>
  <Option condition={a}>
    <A />
  </Option>
  <Option condition={b}>
    <B />
  </Option>
  <Option default>
    <Fallback />
  </Option>
</SuperSwitch>

Use this mode when visual order already represents priority.

2. priority

Options are evaluated by explicit priority.

• All <Option /> elements must define priority
• Lower numbers mean higher priority (1 beats 2)
• Order in JSX does not matter
• Default options are still supported

<SuperSwitch mode="priority">
  <Option condition={a} priority={2}>
    <A />
  </Option>
  <Option condition={b} priority={1}>
    <B />
  </Option>
  <Option default priority={99}>
    <Fallback />
  </Option>
</SuperSwitch>

Use this mode when:

• Business rules are complex
• Priority changes frequently
• You want cleaner diffs and safer refactors

Default option behaviour

• At most one option is rendered
• If no conditions match:
  • the first default option is rendered
• If no default exists, an error is thrown

Runtime validation (development safety)

Invalid children

<SuperSwitch>
  <div /> {/* ❌ not allowed */}
</SuperSwitch>

Missing default

<SuperSwitch>
  <Option condition={false}>
    <A />
  </Option>
</SuperSwitch>

Invalid priority usage

<SuperSwitch mode="priority">
  <Option condition={a} priority={1}>
    <A />
  </Option>
  <Option condition={b}>
    <B />
  </Option>{" "}
  {/* ❌ missing priority */}
</SuperSwitch>

When should you use this library?

• When rendering logic depends on multiple independent conditions
• When only one view must ever render
• When priority must be explicit and reviewable
• When you want fail-fast behaviour instead of silent bugs

When not to use it

• Simple ternaries
• Binary conditions (if / else)
• List rendering (map)

Comparison with existing libraries

There are a few existing React libraries that aim to improve conditional rendering. They are useful in certain scenarios, but they solve a different class of problems than react-super-switch.

The goal of this library is deterministic, exclusive rendering with explicit prioritisation and fail-fast guarantees.

---

react-switch

react-switch provides a JSX-friendly abstraction similar to a switch / case statement.

What it’s good at:

• Cleaner syntax than inline && expressions
• Familiar switch-like mental model

Limitations:

• Multiple cases can render at the same time
• No priority or ordering guarantees
• No enforced default or fallback
• No runtime validation

react-switch assumes conditions are mutually exclusive, but does not enforce that assumption.

---

react-if

react-if models imperative if / else if / else logic in JSX.

What it’s good at:

• Simple, linear conditional flows
• Readable for small, sequential branches

Limitations:

• Conditions must be logically chained
• No concept of independent business rules
• No priority system
• Does not guarantee that only one branch renders

This approach works well for simple control flow, but becomes hard to maintain when conditions are unrelated or derived from complex business logic.

---

react-if-vz

react-if-vz is conceptually closer to react-super-switch and attempts to introduce more structured conditional rendering.

Limitations:

• Largely unmaintained
• Weak TypeScript support
• No enforced exclusivity
• Priority is implicit rather than guaranteed
• No fail-fast validation

---

Why react-super-switch exists

react-super-switch focuses on correctness and intent, not just syntax:

• Exactly one option is rendered, or an error is thrown
• Priority is a first-class concept
• Default behaviour is explicit and enforced
• Invalid configurations fail loudly during development
• JSX remains clean and declarative

If your rendering logic depends on multiple independent conditions and only one view must ever render, react-super-switch is designed specifically for that use case.

License

MIT