Editor service should not create untitled editors before overrides

[abrasaxdeity]

Add a command to the existing custom editor sample extension

{ "command": "catCustoms.catScratch.new", "title": "Create new Cat Scratch Document", "category": "Cat Scratch" }

register command in extension.ts

vscode.commands.registerCommand('catCustoms.catScratch.new', () => { vscode.workspace.openTextDocument({ language: 'catScratch', content: '' }).then(doc => { vscode.commands.executeCommand("vscode.openWith", doc.uri, "catCustoms.catScratch"); }); });

1. Open command palette and select Create new Cat Scratch Document - Untitled-1 tab opens
2. Close opened editor
3. Repeat 1. - Untitled-2 opens

Bug is in step 3, since Untitled-1 was previously closed name should be free for the new untitled file

[bpasero]

I saw this recently and forgot to follow up: there is an easier repro for this and I think somewhere when custom text editors were added, we forgot to deal with untitled models properly. I think they are not getting freed up.

Steps:

• revert my change in 7686b52
• run out of sources
• select File > New File
• you should get a picker to pick an editor
• click ESC to close picker
• repeat

=> 🐛 you see Untitled-2 and this continues

[bpasero]

@lramos15 I think this will be part of your work: with the new override handling moving out of the editor group I think this should be fixed as well because we will no longer create an untitled editor input before the override has happened 👍

[lramos15]

Optimistically closing. I wasn't able to get the repro steps above to work, but when I create new untitled files with the hex editor the number no longer increments.

[roblourens]

I repro this with the original steps

[lramos15]

@bpasero or @mjbvz I think I need some help with this one, I'm not sure where these models are getting created / why they're sticking around. I don't really see this else where just in this particular open flow.

[bpasero]

Untitled text models typically get created through the IUntitledTextEditorModelManager.create method, but in theory you can also ask the IEditorService#createEditorInput method to create a untitled editor input with associated model for you when you pass in no resource and give contents in the arguments.

I am not sure where in custom editor land untitled files are created.

[lramos15]

It seems like openTextDocument creates a model, and then openWith creates a second one. I fixed properly disposing the openWith model here 9f32d37 (At least I think, I'm not sure if it's expected that the editor input would be disposed in this service). However, I have no way to handle the openTextDocument model disposing as that isn't handled by the editor service flow. Seems like this feature request might cleanup this flow #93441

[bpasero]

I would argue that it should be the IEditorService that creates EditorInput from the untyped ones and that one should properly be disposed if it gets overridden by the editor override service. We are probably not there yet because we still allow someone to pass in an EditorInput to the IEditorService and then have questionable lifecycle issues.

As soon as everyone only uses untyped editor inputs, the lifecycle is a lot clearer and owned only by editor service and editor override service.

[bpasero]

I have renamed the issue. I think #124352 would probably fix this. The gist is that we should stay away from creating UntitledTextEditorInput in the editor service before the overrides because it is possible that an override kicks in and then the untitled text editor was created for no good reason and possibly leaks.

[bpasero]

I think this can be closed?

[rzhao271]

I can still reproduce the issue with the original steps.

Edit: I've created a repro here https://github.com/microsoft/vscode-extension-samples/tree/rzhao271/106012-repro/custom-editor-sample.

[lramos15]

Ah the steps aren't the same since custom editors don't properly implement the untitled factory yet. I'm not sure the best way to verify this @bpasero but I know it no longer creates the untitled input.

[bpasero]

This should be the steps:

• install GH issue extension notebook
• from command line start vscode on a *.github-issues file that does not exist
• it should open a issue notebook editor
• close that
• File > New File
• it should be "Untitled-1"

Previously it would be "Untitled-2", indicating that we leaked a typed untitled editor.