https://github.com/luanrt/jinter
A tiny JavaScript interpreter written in TypeScript
https://github.com/luanrt/jinter
interpreter javascript vm
Last synced: 9 months ago
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A tiny JavaScript interpreter written in TypeScript
- Host: GitHub
- URL: https://github.com/luanrt/jinter
- Owner: LuanRT
- License: mit
- Created: 2022-08-19T08:14:14.000Z (almost 4 years ago)
- Default Branch: main
- Last Pushed: 2025-09-11T03:37:03.000Z (10 months ago)
- Last Synced: 2025-09-18T05:23:31.750Z (10 months ago)
- Topics: interpreter, javascript, vm
- Language: TypeScript
- Homepage: https://www.npmjs.com/package/jintr
- Size: 503 KB
- Stars: 37
- Watchers: 2
- Forks: 7
- Open Issues: 4
-
Metadata Files:
- Readme: README.md
- Changelog: CHANGELOG.md
- License: LICENSE
Awesome Lists containing this project
README
[actions]: https://github.com/LuanRT/Jinter/actions
Jinter
A tiny JavaScript interpreter written in TypeScript
[][actions]
> **Note**: This project was originally developed for use in [YouTube.js](https://github.com/LuanRT/YouTube.js).
## Table of Contents
- [Installation](#installation)
- [Usage](#usage)
- [API](#api)
- [`evaluate(input: string)`](#evaluateinput-string)
- [`visitor`](#visitor)
- [`scope`](#scope)
- [License](#license)
## Installation
```sh
npm install jintr
```
## Usage
Execute some JavaScript code:
```ts
// const Jinter = require('jintr').default;
import { Jinter } from 'jintr';
const code = `
function sayHiTo(person) {
console.log('Hi ' + person + '!');
}
sayHiTo('mom');
`
const jinter = new Jinter();
jinter.evaluate(code);
```
---
Inject your own functions, objects, etc:
```ts
import { Jinter } from 'jintr';
const jinter = new Jinter();
const code = `
console.log(new SomeClass().a);
console.log('hello'.toArray());
function myFn() {
console.log('[myFn]: Who called me?');
}
myFn();
`;
class SomeClass {
constructor() {
this.a = 'this is a test';
}
}
jinter.defineObject('SomeClass', SomeClass);
// Ex: str.toArray();
jinter.visitor.on('toArray', (node, visitor) => {
if (node.type === 'CallExpression' && node.callee.type === 'MemberExpression') {
const obj = visitor.visitNode(node.callee.object);
return obj.split('');
}
});
// Intercept function calls
jinter.visitor.on('myFn', (node) => {
if (node.type == 'CallExpression')
console.info('myFn was called!');
return '__continue_exec';
});
jinter.evaluate(code);
```
For more examples see [`/test`](https://github.com/LuanRT/Jinter/tree/main/test) and [`/examples`](https://github.com/LuanRT/Jinter/tree/main/examples).
## API
* Jinter()
* [`evaluate(input: string)`](#evaluate)
* [`visitor`](#visitor)
* [`scope`](#scope)
### `evaluate(input: string)`
Evaluates the given JavaScript code.
### `visitor`
The node visitor. This is responsible for walking the AST and executing the nodes.
### `scope`
Represents the global scope of the program.
## License
Distributed under the [MIT](https://choosealicense.com/licenses/mit/) License.