Debug Protocol: Add a "url" field to "source" objects

[andrewcrawley]

We'd like to add a url field to Source objects to support more advanced mappings from url to local file that VS can perform based on project system information while debugging JS running in a browser.

Proposal:

export interface Source {
    // ...

    /** The URL of the source, if available. */
    url?: string;

    // ...
}

We'd prefer a separate field rather than re-using the path field so that debug adapters can continue to support their own source mapping mechanisms while still allowing the host to do more advanced mapping if available.

Namedrops: @weinand @richardstanton @gregg-miskelly @digeff @roblourens

[roblourens]

Can you tell me more about what additional info you get from the project system? Can this info be encoded in the launch config via pathMapping and sourceMapPathOverrides (in vscode-chrome-debug-core), so the adapter can do the mapping?

[digeff]

There might be virtual directories, bundles, minified files, symbolic links, and all kind of features that can make the mapping very complex. Some of these features can be language/library/framework specific too.

[roblourens]

The adapter typically has to handle those things anyway, and I'd like to make it work in all scenarios, rather than bypass it, when possible.

I've mostly avoided too many framework-specific adjustments, except for some tweaks to handle webpack and meteor-specific sourcemap paths.

[andrewcrawley]

Rob informed us that it's already possible to configure the adapter to return urls, so I don't think we need this. Diego is going to test that out, and I'll re-open the issue if necessary.