VS Code - Debugger for Edge

A VS Code extension to debug your JavaScript code in the Edge browser.

This extension is pre-release and you will encounter bugs on the way so let us know on our issues page.

Getting started

To get started, you simply open the Command Palette inside VS Code and type ext install to run the Extensions: Install Extension command. When the extension list appears, type 'edge' to filter the list and install the Debugger for Edge extension.

Configuration

The extension operates in two modes - it can launch an instance of Edge navigated to your app, or it can attach to a running instance of Edge.

Just like when using the Node debugger, you configure these modes with a .vscode/launch.json file in the root directory of your project. You can create this file manually, or Code will create one for you if you try to run your project, and it doesn't exist yet.

To use this extension, you must first open the folder containing the project you want to work on.

Launch mode

Two example launch.json configs. You must specify either file or url to launch Edge against a local file or a url. If you use a url, set webRoot to the directory that files are served from. This can be either an absolute path or a path relative to the workspace (the folder open in Code). It's used to resolve urls (like http://localhost/app.js) to a file on disk (like /users/me/project/app.js), so be careful that it's set correctly.

{
    "version": "0.1.0",
    "configurations": [
        {
            "name": "Launch localhost with sourcemaps",
            "type": "edge",
            "request": "launch",
            "url": "http://localhost/mypage.html",
            "webRoot": "${workspaceRoot}/app/files",
            "sourceMaps": true
        },
        {
            "name": "Launch index.html (without sourcemaps)",
            "type": "edge",
            "request": "launch",
            "file": "${workspaceRoot}/index.html"
        },
    ]
}

Attach mode

Attaches the debugger to an already running instance of Edge.

{
    "version": "0.1.0",
    "configurations": [
        {
            "name": "Attach with sourcemaps",
            "type": "edge",
            "request": "attach",
            "url": "http://localhost/mypage.html", // optional: used to find the right tab running in Edge
            "port": 9222,
            "sourceMaps": true
        },
        {
            "name": "Attach to url with files served from ./out",
            "type": "edge",
            "request": "attach",
            "port": 9222,
            "webRoot": "${workspaceRoot}/out"
        }
    ]
}

Supported features

In this release, we support the following features:

• Setting breakpoints, including within source files when source maps are enabled
• TypeScript, via source maps
• Debug stepping
• Locals scope variables via the VARIABLES panel
• Debugging eval scripts, script tags, and scripts that are added dynamically
• Watches via the WATCH panel.
• The debug console
• Most console APIs

Known limitations

Launching Edge

There's a few issues with launching Edge, you're best bet is to have your page already open and attach to it.

1. You have to have one tab open in Edge. Opening Edge for the first time from VS Code will get a hung page.

Multiple Tabs with the same Url

The logic for picking which tab to attach to is based on the URL. If you have multiple tabs open at the same URL VS Code will attach to the first one.

No Console API

Currently the console.* API is not implemented so you won't see log messages in the console in VS Code. You can execute statements and inspect the results as normal though.

No Pause Overlay

Currently there is no indication in Edge when you are paused at a breakpoint in VS Code. You'll still see your site but won't be able to interact with it and the tab will eventually be reported as "Not responding".

No Support for Web Workers

Currently there is no support for debugging of web workers in Edge.

No Inlined Sourcemap Support

Sourcemaps that are included in the compiled JS aren't currently supported.

Broken Stepping

Occasionally, typically if you've been at a breakpoint for a while and tried to interact with the page you'll see that stepping no longer seems to be working. This can happen when Edge recycles the tab and moves the one being debugged to a hidden tab and in it's place creates a new page at the same URL.

Troubleshooting

General things to try if you're having issues:

• Ensure webRoot is set correctly if needed
• Look at your sourcemap config carefully. A sourcemap has a path to the source files, and this extension uses that path to find the original source files on disk. Check the sourceRoot and sources properties in your sourcemap and make sure that they can be combined with the webRoot property in your launch config to build the correct path to the original source files.
• Only have one instace of Edge running
• Ensure nothing else is using port 9222, or specify a different port in your launch config
• Check the console for warnings that this extension prints in some cases when it can't attach
• Ensure the code in Edge matches the code in Code. Edge may cache an old version.
• If you set a breakpoint in code that runs immediately when the page loads, you won't hit that breakpoint until you refresh the page.
• File a bug in this extension's GitHub repo. Set the diagnosticLogging field in your launch config to true and attach the logs when filing a bug.

Code of Conduct

This project has adopted the Microsoft Open Source Code of Conduct. For more information see the Code of Conduct FAQ or contact [email protected] with any additional questions or comments.