node script file that extension name is '.njs' can't be debug，throw err：Cannot launch program setting the 'outFiles' attribute might help

[purplestone]

• VSCode 1.15.1
• OS win7 x64
• Shell 1.6.6
• Render 56.0.2924.87
• Nodejs 7.4.0

launch.json:

{
    "version": "0.2.0",
    "configurations": [
        {
            "type": "node",
            "request": "launch",
            "name": "Launch Program",
            "program": "${file}"
        }
    ]
}

Create a file name ： go.njs:

debugger;
console.log();

press F5 to debug throw: Cannot launch program ”xxx\js\go.njs“ setting the 'outFiles' attribute might help

But I rename that file extension name '.njs' to '.js', It works well.

[weinand]

I've never heard of a file extension "njs".
Can you point me to a definition?

[purplestone]

In /Microsoft VS Code/resources/app/extensions/javascript/package.json
the js file extensions can be name:
"extensions": [
".js",
".es6",
".jsx",
".mjs"
],

So I name my node script files to '*.njs',

The above extension names will throw err except '.js'
IDE should not restrict my script file extension name, I had specified execute type of script file ("type": "node")

[MikeRalphson]

@purplestone note above the list of extensions includes .mjs not .njs (em, not en).

I'm not sure if renaming your module to .mjs will fix the debugger issue though, as I am getting the same error trying to debug a .mjs module in Node 9 nightly using the --experimental-modules runtimeArgs.

[MikeRalphson]

@weinand this looks to be an issue in https://github.com/microsoft/vscode-node-debug2

The javascript debugger only wants to debug files where

            if (utils.isJavaScript(programPath)) {

is true. See line 467

This test is only satisfied if the programPath ends with .js or there is a specific node shebang string at the top of the file:

const NODE_SHEBANG_MATCHER = new RegExp('#! */usr/bin/env +node');
//...
if (name.endsWith('.js')) {
        return true;
}
//...
if (NODE_SHEBANG_MATCHER.test(line)) {

Adding

#!/usr/bin/env node

to the top of the affected .mjs file allows it to be debugged.

The assumption seems to be that .mjs files will always generate .js source files (i.e. via babel etc), but this assumption is no longer true with native .mjs support in recent Node.js builds (even if this is currently behind a flag).

[JoseBalado]

Hi, I can not debug node.js modules with the .mjs extension unless I add #!/usr/bin/env node to the top of the module.
Tested with Node v8.5.0 and v8.6.0 using --experimental-modules flag.

Thanks for your solution @MikeRalphson

[weinand]

I've added the extensions ".js", ".es6", ".jsx", ".mjs" to the list of recognised JavaScript extensions.

[weinand]

Verify that you can debug a JavaScript program if the file extension is ".es6", ".jsx", ".mjs".

[JoseBalado]

@weinand It works with ".mjs" extension.
Thanks