1594550 - Support `name` values from source maps for lower-fidelity variable mapping

Status: NEW

(DevTools :: Debugger, enhancement, P2)

Description

[:Harald Kirschner :digitarald]

Follow up from https://bugzilla.mozilla.org/show_bug.cgi?id=1590588#c4 .

Firefox users get a great scope mapping experience with the optional Map scopes option on, while Chrome does an acceptable job without the overhead.

Comment 1

[Andrei Petcu]

In my other bug I mentioned cheap-module-source-map https://github.com/firefox-devtools/debugger/issues/8292 but I think I can see a similar issue with source-map also.

If you sign up to https://cloud.uipath.com you will see the issue in this web page. You can sign up with any email address, no charge since it will be a community account.

You can set a breakpoint in HomePageComponent.tsx at line 32 for example you will see that by default Chrome will show the local variables really fast while Firefox does not. If I enable Map in Firefox it will take a while and it will actually show this as in Chrome.

Comment 2

[Andrei Petcu]

Can the lack of name values from source map trigger this other issue I reported? https://bugzilla.mozilla.org/show_bug.cgi?id=1653779

Comment 3

[Alexandre Poirot [:ochameau] [PTO back August 21]]

Holger, I was wondering about these bugs and especially bug 1590588 comment 4. Is this something we can use until the source map spec is improved and implemented?

Comment 4

[Holger Benl [:hbenl]]

(In reply to Alexandre Poirot [:ochameau] from comment #3)

Holger, I was wondering about these bugs and especially bug 1590588 comment 4. Is this something we can use until the source map spec is improved and implemented?

We could but I don't know if it's worth the effort: in my experience the quality of the name values in source mappings is very inconsistent and using them to reconstruct original scopes (without parsing the sources) may not be as straightforward as it may seem.