jsenv-execution

Introduction

@jsenv/execution is capable to execute a javaScript file on a browser or Node.js.

It has the following exports

• execute

How to use

Using a basic project setup we'll see how to use execute to create script capable to execute file inside chromium or node.js.

Basic project setup

1. Create basic project file structure

   — see ./docs/basic-project

2. Install dependencies

   npm install

Browser execution with chromium

node ./execute-chromium.js index.js

browser will be logged in your terminal.

Node execution

node ./execute-node.js index.js

node will be logged in your terminal.

Use execute to debug file withing vscode

What if you could debug inside node.js the file currently opened in vscode?

1. Add a launch configuration in basic-project/.vscode/launch.json

{
  "version": "0.2.0",
  "configurations": [
    {
      "name": "jsenv-node",
      "type": "node",
      "request": "launch",
      "protocol": "inspector",
      "program": "${workspaceFolder}/execute-node.js",
      "args": ["${relativeFile}"],
      "autoAttachChildProcesses": true,
      "sourceMaps": true,
      "sourceMapPathOverrides": {
        "/*": "${workspaceFolder}/*"
      },
      "smartStep": true,
      "skipFiles": ["node_modules/**", "<node_internals>/**/*.js"]
    }
  ]
}

2. Start a debugging session using jsenv node

I made a video of the debugging session inside vscode. The gif below was generated from that video.

Sometimes vscode fails to auto attach child process debugging session.
According to my experience it happens mostly on windows.
When it happens you must manually attach it.

To do that you can add an other configuration in your launch.json.

{
  "name": "jsenv-node-attach-child",
  "type": "node",
  "request": "attach",
  "port": 3456,
  "smartStep": true,
  "sourceMaps": true,
  "sourceMapPathOverrides": {
    "/*": "${workspaceFolder}/*"
  },
  "skipFiles": ["node_modules/**", "<node_internals>/**/*.js"]
}

Using this configuration also means your child process debug session listens at 3456. You must update the execute-node script to force 3456 port like this:

const { execute } = require("@jsenv/execution")
const { launchNode } = require("@jsenv/node-launcher")

execute({
  projectPath: __dirname,
  launch: (options) => launchNode({ ...options, debugPort: 3456 }),
  fileRelativePath: `/${process.argv[2]}`,
})

If you want to know more about execute, there is a more detailed documentation on it.
— see execute documentation