AutoSave is triggering editor.formatOnSave even when files.autoSave is afterDelay

[hb20007]

Does this issue occur when all extensions are disabled? Yes*

*The issue occurs when all extensions are disabled, except for Prettier, which I use for the opinionated formatting to demonstrate the severity of the issue. (It is, of course, also reproducible without Prettier; see my comments below.)

I am able to reproduce the issue on Windows (v1.87.0) as well as on the Insiders build on web using https://insiders.vscode.dev/.

Steps to Reproduce

I will provide the steps to reproduce it on the Insiders build:

1. Launch a fresh build of VS Code.
2. Download the Prettier extension.
3. Add the following in user settings:
   
   (It seems that the Insiders build has "files.autoSave": "afterDelay" as the default so there’s no need to add that. If using another version, you need to add it.)
4. Create a new .js file and type the following:
   
5. Press Alt + Tab twice.
6. Notice that the code has been autoformatted:
   

More Info

This is a major annoyance as "editor.formatOnSave": true is not meant to be triggered if the file is saved after delay, as the description of the property also says.

I see that someone has already reported this bug 3 weeks ago in #204884, but it was closed as the user did not confirm that the issue happens even when other extensions are disabled.

Also, I see that there is another open issue (#206434) related to "files.autoSave": "onFocusChange". Both issues might have been caused by the same commit.

System Info

Item	Value
CPUs	AMD Ryzen 7 5700U with Radeon Graphics (16 x 1797)
GPU Status	2d_canvas: enabled canvas_oop_rasterization: enabled_on direct_rendering_display_compositor: disabled_off_ok gpu_compositing: enabled multiple_raster_threads: enabled_on opengl: enabled_on rasterization: enabled raw_draw: disabled_off_ok skia_graphite: disabled_off video_decode: enabled video_encode: enabled vulkan: disabled_off webgl: enabled webgl2: enabled webgpu: enabled
Memory (System)	7.31GB (1.38GB free)
Screen Reader	no
VM	0%

[starball5]

Related on Stack Overflow: When I hit alt+tab, VS code do auto save, and formats code, how to stop it?

[hb20007]

Related on Stack Overflow: When I hit alt+tab, VS code do auto save, and formats code, how to stop it?

I am aware of this too. The user there does not confirm that they aren't using "files.autoSave": "onWindowChange" so I wasn't sure if I should link to it.

[jrieken]

The issue occurs when all extensions are disabled, except for Prettier, which I use for the opinionated formatting to demonstrate the issue.

How we do you know this isn't caused by prettier then? Please disable and configure one of the built-in formatters, e.g the one for JS/TS, and check if you can reproduce

[jrieken]

Also, what do you have configured for files.autoSave? With off, prettier, and your steps I cannot reproduce this.

[hb20007]

@jrieken I already mentioned the configuration for files.autoSave… Please see step 3 in the steps to reproduce. The value should be "files.autoSave": "afterDelay".

[jrieken]

It seems that the Insiders build has "files.autoSave": "afterDelay" as the default so there’s no need to add that. If using another version, you need to add it.

That's not correct - the default is off. You likely have changed this setting or a workspace or extension has.

[jrieken]

[hb20007]

@jrieken On the Insiders build, I see this:

As you can see, afterDelay is the predefined option.

[hb20007]

@jrieken,

Please reopen the issue. I have instructions to reproduce it without Prettier:

1. Launch a fresh build of VS Code.
2. Add the following in user settings:
   
   (Make sure that you also set "files.autoSave": "afterDelay" if it is not set for you by default.)
3. Create a new .js file and type the following:
   
4. Press Alt + Tab twice.
5. Notice that the code has been autoformatted (a semicolon was added):
   

If the issue does not get reproduced on the first attempt, try to manually save the file first and then try to reproduce it by removing the semicolon and pressing Alt + Tab.

[jrieken]

@bpasero I see in code that afterDelay is the default for web (but not desktop). However, in the formatting save participant I explicitly check for AUTO and return early:

vscode/src/vs/workbench/contrib/codeEditor/browser/saveParticipants.ts

Line 224 in d374d10

if (context.reason === SaveReason.AUTO) {

Is there a case, esp with Alt+Tab, that causes a save event with a different reason?

[bpasero]

This actually seems to be a regression.

Web has auto save enabled by default because we were bold enough to decide this and saving in web felt wrong. It should have really been the default for desktop too, but is not, neither in stable nor insiders.

[dhruvArora8053]

Related on Stack Overflow: When I hit alt+tab, VS code do auto save, and formats code, how to stop it?

I am aware of this too. The user there does not confirm that they aren't using "files.autoSave": "onWindowChange" so I wasn't sure if I should link to it.

Yes I am not using the above instruction but problem still persists.

[hb20007]

Yes I am not using the above instruction but problem still persists.

The issue is no longer reproducible on the Insiders edition, so it should be fixed in the March release.