jintr

Jinter

A tiny JavaScript interpreter written in TypeScript

Note: This project was originally developed for use in YouTube.js.

Usage

Execute some JavaScript code:

// const Jinter = require('jintr').default;
import Jinter from 'jintr';

const code = `
  function sayHiTo(person) {
    console.log('Hi ' + person + '!');
  }
  
  sayHiTo('mom');
`

const jinter = new Jinter(code);
jinter.interpret();

---

Inject your own functions and variables into the interpreter:

// ...

jinter.visitor.on('println', (node, visitor) => {
  if (node.type === 'CallExpression' && node.callee.type === 'MemberExpression') {
    const args = node.arguments.map((arg) => visitor.visitNode(arg));
    return console.log(...args);
  }
});

// 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('');    
  }  
});

// Or you can just intercept access to specific nodes;
jinter.visitor.on('myFn', (node, visitor) => {
  console.info('MyFn node just got accessed:', node);
  return 'proceed'; // tells the interpreter to continue execution 
});

jinter.interpret();

For more examples see /test and /examples.

License

Distributed under the MIT License.

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