Uses the Node.js vm to isolate a RegExp so catastrophic backtracks do not halt the node process.

no_redos.js

const util = require('util');
const vm = require('vm');
 
var sandbox = {
    result: null
};
 
var context = vm.createContext(sandbox);
console.log('Sandbox initialized: ' + vm.isContext(sandbox));
 
var script = new vm.Script('result = /^(A+)*B/.test(\'AAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAAC\');');
 
try{
    // One could argue if a RegExp hasn't processed in a given time.
    // then, its likely it will take exponential time.
    script.runInContext(context, { timeout: '1000' }); // milliseconds
} catch(e){
    console.log('ReDos occurred'); // Take some remedial action here...
}
 
console.log(util.inspect(sandbox)); // Check the results