This project is a thin wrapper around the Duktape Embedded Javascript Engine compiled to webassembly/asmjs.
while(true) {} lock up).DuktapeVM().then((vm) => {
vm.eval("2 + 2") // returns "4";
vm.eval("var testObj = {foo: 'bar'};");
vm.eval("testObj.foo") // returns "bar";
vm.evalAsync(`
setTimeout(function() {
_success("hello, " + args[0]);
}, 1000);`,
["world!"]
).then((res) => {
console.log(res) // hello, world!
})
// destroy vm
vm.destroy();
});
npm i duktape-vm --save
Using in Typescript/Babel project:
import { DuktapeVM } from "duktape-vm";
Using in Node:
const DuktapeVM = require("duktape-vm").DuktapeVM;
To use directly in the browser, drop ONE of the tags below into your <head>.
The library will attach DuktapeVM to window/global, allowing you to access it anywhere in your code.
<!-- Webassembly Only Version (Fast with 75% browser support), 110KB -->
<script src="https://cdn.jsdelivr.net/npm/duktape-vm@0.1.3/build/duktape-vm.min.js"></script>
<!-- AsmJS Only Version (Slower with 95% browser support), 115KB -->
<script src="https://cdn.jsdelivr.net/npm/duktape-vm@0.1.3/build/duktape-vm.min.asm.js"></script>
<!-- Webassembly with AsmJS fallback (Fast with 95% browser support), 220KB -->
<script src="https://cdn.jsdelivr.net/npm/duktape-vm@0.1.3/build/duktape-vm.min.both.js"></script>
The vm doesn't expose any platform specific methods like window, document, global, fetch or anything like that. Only a subset of APIs are available: setInterval, setTimeout, clearTimeout, clearInterval, Date, Array, String, Number, Object, RegExp, JSON, parseInt, isNaN and Promise.
Additional methods and variables can be provided by passing them into the DuktapeVM constructor.
DuktapeVM(`
// Provide data and methods to VM instance
// vm_breakout() allows you to eval code in the parent window/global space.
// vm_breakout is only available here, it's not available in subsequent "vm.eval" or "vm.evalAsync" calls.
// all methods should be attached to the exports object
exports.console = function(message) {
// print to parent console
vm_breakout("console.log('" + message + "');")
};
// you can also inline js libraries here
// global scope is available on the variable "self"
`).then((vm) => {
// vm contains the javascript vm reference
// Standard eval
let value = vm.eval("2 + 2"); // value contains "4";
// Eval with arguments
// arguments are passed as array called "args"
// when you use arguments you muse use "return" if you want to get the value back.
vm.eval(`return args[0] + args[1]`, [2, 3]); // returns 5
// Messaging API
vm.eval(`
exports.onMessage(function(msg) {
// got message from parent!
})
// send message to parent
exports.message("some message to parent");
`);
// Send message to vm
vm.message("this is a message to the vm");
// Listen for messages from vm
vm.onMessage((msg) => {
console.log("Got message from vm: " + msg);
});
// Async eval
// use _success and _error as callbacks
vm.evalAsync(`
setTimeout(function() {
_success("done!");
// _error("something went wrong!");
}, 1000);
`).then((result) => {
console.log(result) // "done"
});
// Async Eval with arguments
// arguments are passed in as "args" array
vm.evalAsync(`
setTimeout(function() {
_success(args[0]);
// _error("something went wrong!");
}, 1000);
`, ["hello world!"]).then((result) => {
console.log(result) // "hello world!"
});
// destroy vm
vm.destroy();
})
Copyright (c) 2018 Scott Lott
Permission is hereby granted, free of charge, to any person obtaining a copy of this software and associated documentation files (the "Software"), to deal in the Software without restriction, including without limitation the rights to use, copy, modify, merge, publish, distribute, sublicense, and/or sell copies of the Software, and to permit persons to whom the Software is furnished to do so, subject to the following conditions:
The above copyright notice and this permission notice shall be included in all copies or substantial portions of the Software.
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
FAQs
Javascript VM running in WebAssembly
The npm package duktape-vm receives a total of 1 weekly downloads. As such, duktape-vm popularity was classified as not popular.
We found that duktape-vm demonstrated a not healthy version release cadence and project activity because the last version was released a year ago. It has 1 open source maintainer collaborating on the project.
Did you know?
Socket for GitHub automatically highlights issues in each pull request and monitors the health of all your open source dependencies. Discover the contents of your packages and block harmful activity before you install or update your dependencies.
Security News
Research
Socket researchers have discovered malicious npm packages targeting crypto developers, stealing credentials and wallet data using spyware delivered through typosquats of popular cryptographic libraries.
Security News
Socket's package search now displays weekly downloads for npm packages, helping developers quickly assess popularity and make more informed decisions.
Security News
A Stanford study reveals 9.5% of engineers contribute almost nothing, costing tech $90B annually, with remote work fueling the rise of "ghost engineers."