fix: capture render tree can fail if args cannot be obtained

[patricklx]

this currently happens on https://meta.discourse.org/ when checking with ember-inspector and not being logged in.

[NullVoxPopuli]

hello! can a test be added? thanks!

[patricklx]

Hi, where can I add that?

[NullVoxPopuli]

maybe in here? https://github.com/glimmerjs/glimmer-vm/blob/master/packages/%40glimmer-workspace/integration-tests/test/debug-render-tree-test.ts

[patricklx]

added the tests for this.
Could this also be backported?

[patricklx]

@NullVoxPopuli

[NullVoxPopuli]

unsure, what version would you want to backport to?

[NullVoxPopuli]

for others, a repro of the problem: https://stackblitz.com/edit/github-pgxsyq?file=app%2Fcomponents%2Fwelcome.gts

(open the ember inspector, ensure the throw is happening, and see that the component view is blank)

[patricklx]

Backportel to lts versions would be nice i think

[NullVoxPopuli]

glimmer-vm doesn't have an LTS tho 😅

an issue is that even if we fix ember-LTS, all the versions in between won't be fixed, because glimmer-vm is bundled with ember-source right now.

[patricklx]

@NullVoxPopuli i think we need to revert this.
it affects also other parts of glimmer...

[NullVoxPopuli]

How do you mean? Can we add more tests to prevent whatever it in you've discovered?

[NullVoxPopuli]

Looks like #1460 explains

[patricklx]

for example here it is used: https://github.com/glimmerjs/glimmer-vm/blob/master/packages/%40glimmer/runtime/lib/helpers/fn.ts#L87.
in application this change would have caught errors, and the developer would not see it in the app...

[NullVoxPopuli]

Oofta, that tells me we don't have sufficient failure-case testing