arepl-backend

AREPL-backend

JS interface to python evaluator for AREPL.

Evaluates python code and sends back the user variables and/or any errors.

Although it is meant for AREPL, it is not dependent upon AREPL and can be used by any project.

Important Note: this should ONLY be used to execute trusted code. It does not have any security features whatsoever.

Installation

npm install arepl-backend

must have python 3.7 or greater

Usage

see https://github.com/Almenon/AREPL-vscode for example useage.

For developers:

Semantic release cheatsheet:

| Commit message       | Release type |
|----------------------|--------------|
| fix: msg             | patch        |
| feat: msg            | feature      |
| perf: msg            |              |
| BREAKING CHANGE: msg | breaking     |

API

Table of Contents

• constructor
  • Parameters
• executing
• running
• debounce
• execCode
  • Parameters
• sendStdin
  • Parameters
• restart
  • Parameters
• stop
• start
• onResult
  • Parameters
• onPrint
  • Parameters
• onStderr
  • Parameters
• handleResult
  • Parameters
• checkSyntax
  • Parameters
• checkSyntaxFile
  • Parameters
• formatPythonException
  • Parameters
  • Examples

constructor

starts python_evaluator.py

Parameters

• options Process / Python options. If not specified sensible defaults are inferred. (optional, default {})

executing

whether python is busy executing inputted code

running

whether python backend process is running / not running

debounce

delays execution of function by ms milliseconds, resetting clock every time it is called Useful for real-time execution so execCode doesn't get called too often thanks to https://stackoverflow.com/a/1909508/6629672

execCode

does not do anything if program is currently executing code

Parameters

• code

sendStdin

Parameters

• message string

restart

kills python process and restarts. Force-kills if necessary after 50ms. After process restarts the callback passed in is invoked

Parameters

• callback (optional, default ()=>{})

stop

kills python process. force-kills if necessary after 50ms. you can check python_evaluator.running to see if process is dead yet

start

starts python_evaluator.py. Will NOT WORK with python 2

onResult

Overwrite this with your own handler. is called when program fails or completes

Parameters

• foo

onPrint

Overwrite this with your own handler. Is called when program prints

Parameters

• foo string

onStderr

Overwrite this with your own handler. Is called when program logs stderr

Parameters

• foo string

handleResult

handles pyshell results and calls onResult / onPrint

Parameters

• results string

checkSyntax

checks syntax without executing code

Parameters

• code string

Returns Promise rejects w/ stderr if syntax failure

checkSyntaxFile

checks syntax without executing code

Parameters

• filePath string

Returns Promise rejects w/ stderr if syntax failure

formatPythonException

gets rid of unnecessary File "" message in exception

Parameters

• err

Examples

err:
Traceback (most recent call last):\n  File "<string>", line 1, in <module>\nNameError: name \'x\' is not defined\n