# Is stop-iteration-iterator ESM-only? Can you require() it?

> stop-iteration-iterator@1.1.0 is a CommonJS package. CommonJS — require() works on every Node.js version we test.

Firefox 17-26 iterators throw a StopIteration object to indicate "done". This normalizes it.

Last verified Sep 9, 2026 against stop-iteration-iterator@1.1.0.

stop-iteration-iterator ships CommonJS only. require("stop-iteration-iterator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.4. import "stop-iteration-iterator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

## What to do

1. require("stop-iteration-iterator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.4.
2. From ES modules use the default import: import stopIterationIterator from "stop-iteration-iterator"; then destructure. Named imports only work when Node.js can statically detect the exports.
3. TypeScript: types are bundled; install nothing extra.

## Facts

- Latest: 1.1.0 (Dec 13, 2024)
- Module format: CommonJS
- Last CommonJS version: 1.1.0
- TypeScript types: bundled
- Node engines: >= 0.4
- Weekly downloads: 69.2M
- License: MIT

## Runtime test results for stop-iteration-iterator@1.1.0

Installed and executed on Sep 9, 2026 with require("stop-iteration-iterator") from a CommonJS file and import "stop-iteration-iterator" from an ES module.

| Runtime | require("stop-iteration-iterator") | import "stop-iteration-iterator" |
|---|---|---|
| Node.js 18 | works | works |
| Node.js 20 | works | works |
| Node.js 22 | works | works |
| Node.js 24 | works | works |
| Node.js 26 | works | works |
| Bun 1.4.0 | works | works |

## How to import stop-iteration-iterator

ES modules:

```js
import stopIterationIterator from "stop-iteration-iterator";
```

CommonJS:

```js
const stopIterationIterator = require("stop-iteration-iterator");
```

## Module format by version

Derived from the type, main and exports fields of every stable release on npm (2 versions; the newest 2 shown).

| Versions | Format | First published |
|---|---|---|
| 1.0.0 – 1.1.0 | CommonJS | Jan 13, 2023 |

## Frequently asked

**Is stop-iteration-iterator ESM-only?**

stop-iteration-iterator@1.1.0 is a CommonJS package. stop-iteration-iterator ships CommonJS only. require("stop-iteration-iterator") works on every Node.js version we test (18, 20, 22, 24 and 26) and in Bun. The package declares Node.js >= 0.4. import "stop-iteration-iterator" also works because Node.js and Bun can import CommonJS from ES modules, but only the default export is guaranteed; named imports depend on Node's static analysis of the module.

**Can I import stop-iteration-iterator with ES module syntax?**

Yes. import stopIterationIterator from "stop-iteration-iterator" works in Node.js and Bun because they support importing CommonJS modules. Named imports work only when Node.js can statically detect the exports.

**Does stop-iteration-iterator work in Bun?**

Yes. import "stop-iteration-iterator" loaded successfully in Bun 1.4.0 on Sep 9, 2026.

**Does stop-iteration-iterator ship TypeScript types?**

Yes. stop-iteration-iterator bundles its own type declarations; no @types package is needed.

## Links

- [stop-iteration-iterator on npm](https://www.npmjs.com/package/stop-iteration-iterator)
- [Source repository](https://github.com/ljharb/stop-iteration-iterator)
- [HTML version](https://canirequire.com/package/stop-iteration-iterator/)
- [JSON version](https://canirequire.com/package/stop-iteration-iterator.json)

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