Errors from the `BatchedExpressionEvaluator` on object inspection

[elliette]

See for example inspecting a Record on chrome:

versus on macos:

This is because the library (and therefore the library URI) for the evaluate request is null:

webdev/dwds/lib/src/services/chrome_proxy_service.dart

Line 626 in 7543345

library?.uri,

FYI @annagrin

[elliette]

I did some looking into this. There are a few things we can do to improve this:

• The targetId argument in evaluate might not be a library ID #2336
• Add retry logic to the BatchedExpressionEvaluator #2337

[annagrin]

AFAIK there should be no evaluate() calls here - how is the example debugged? Are the images from vscode or devtools?

[annagrin]

Here is what I see in VSCode, for example:

[annagrin]

And devtools:

[annagrin]

I suspect some different logic is used here then we do normally - it would be useful to understand where the evaluate is called from and with with what arguments (might be just not a correct usage of evaluate or a lack of support in dwds)

[elliette]

@annagrin figured out what the difference was (why she couldn't initially reproduce whereas I could). She had:

"dart.previewSdkDaps": false

@DanTup - what is the rollout status for the new DAPs?
https://github.com/Dart-Code/Dart-Code/blob/b939d2c45adf2638eac672095c7ac8ed390cffbc/package.json#L2663

[DanTup]

We're at 100% using SDK DAPs for both Dart and Flutter now:

https://github.com/Dart-Code/Dart-Code/blob/b939d2c45adf2638eac672095c7ac8ed390cffbc/src/extension/experiments.ts#L20-L21

The dart.previewSdkDaps setting will soon be renamed and inverted (to become something like dart.useLegacyDebugAdapters) and I would not recommend anyone has it set to false.

(If you think there are bugs in the SDK DAPs that aren't in the legacy DAPs, please let me know)

[annagrin]

I found what is going on - we never supported evaluate() calls on targets other than a library. Looks like DAP sends evaluate requests on getting variables. Will send a PR to fix!

[annagrin]

Depends on: dart-lang/sdk#54609

[elliette]

One note - this is affecting more than just Records. For example, here is what I see when inspecting a Flutter widget's state:

[annagrin]

One note - this is affecting more than just Records

Yes, I could fix the original bug but the record types still are not displaying correctly due to that additional SDK issue:)

[annagrin]

Related: dart-lang/sdk#54694