deno_vm

A Python 3 to Deno + worker-vm binding, helps you execute JavaScript safely.

How it works

The module launches a Deno REPL server, which can be communicated with JSON. All JavaScript code are encoded in JSON and sent to the server. After the server executing the code in vm, the result is sent back to Python.

Install

Install Deno

Follow the instruction here: https://docs.deno.com/runtime/manual/getting_started/installation

Also make sure deno command works as expected: https://docs.deno.com/runtime/manual/getting_started/installation#testing-your-installation

Install deno_vm

pip install deno_vm

Usage

Most of the APIs are bound to worker-vm.

Simple eval:

from deno_vm import eval

print(eval("['foo', 'bar'].join()"))

Use VM:

from deno_vm import VM

with VM() as vm:
   vm.run("""
      var sum = 0, i;
      for (i = 0; i < 10; i++) sum += i;
   """)
   print(vm.run("sum"))

It is possible to do async task with Promise:

from datetime import datetime
from deno_vm import VM

js = """
function test() {
   return new Promise(resolve => {
      setTimeout(() => {
         resolve("hello")
      }, 3000);
   });
};
"""
with VM() as vm:
   vm.run(js)
   print(datetime.now())
   print(vm.call("test"))
   print(datetime.now())

API reference

http://deno_vm.readthedocs.io/

Changelog

• 0.6.0 (Mar 4, 2024)
  • Change: use --unstable-worker-options instead of --unstable.
  • Change: vendor deno dependencies. Now deno_vm doesn't require network and filesystem write access.
  • Fix: suppres cleanup error.
  • Fix: improve uninitialized error message.
• 0.5.1 (Oct 10, 2023)
  • Fix: unable to pass initial code to VM().
• 0.5.0 (Oct 10, 2023)
  • Switch to deno_vm.