Don't activate Python extension until needed (Tests Needed)

[kieferrm]

Issue Type: Bug

When I startup VS Code I get this in a workspace that exclusively contains markdown files. This is the only window I have open. Why?

Extension version: 2021.2.636928669
VS Code version: Code - Insiders 1.55.0-insider (Universal) (9b2ee7fb7d970b9a628fdb3545bdd01d67078d16, 2021-03-11T05:15:23.749Z)
OS version: Darwin arm64 20.3.0

System Info

Item	Value
CPUs	undefined
GPU Status	2d_canvas: enabled gpu_compositing: enabled metal: disabled_off multiple_raster_threads: enabled_on oop_rasterization: enabled opengl: enabled_on protected_video_decode: unavailable_off rasterization: enabled skia_renderer: disabled_off_ok video_decode: enabled webgl: enabled webgl2: enabled
Load (avg)	2, 3, 2
Memory (System)	16.00GB (0.28GB free)
Process Argv	--enable-proposed-api lszomoru.lszomoru-proposed-api-sample --crash-reporter-id ef10dfea-3602-4c74-ba1a-109ce7da7825
Screen Reader	no
VM	0%

A/B Experiments

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vscoresta800:30265947
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[kieferrm]

The activation also happens btw for an empty window, but this time the extension thinks I have a python interpreter, just not the right one:

[brettcannon]

Our activation events are explicitly tied to python commands, language selection, or Python-specific files:

https://github.com/microsoft/vscode-python/blob/f85d5912f89da029a3f4fffcc2d46a387f70cff1/package.json#L51-L94

The only thing that changed recently is we trigger on more Python-related files:

• pyproject.toml
• Pipfile
• setup.py
• requirements.txt
• manage.py
• app.py

Otherwise our activationEvents have not changed in 4 months and that was only for registering a command.

Only other thing involving start-up is we added "requiresWorkspaceTrust": "onStart" recently, but our understanding is that doesn't force activation. Is there a way to see in the logs why an extension was activated?

[kieferrm]

I realized this is because of DonJayamanne/typescript-notebook#4.

[kieferrm]

The real trouble here is the dependency from the Jupyter extension to the Python extension. I.e. when Jupyter activates, Python activates although, as in this case, there is no reason for Python to be active.

[brettcannon]

The long-term plan is to break the hard dependency and make it optional. I suspect Jupyter already has an issue open for this, but in case they don't I'll transfer your issue over to there.

[greazer]

Looks like a dupe of #4965

[rchiodo]

This is a dependency issue. Because the typescript notebook extension loads on startup, it also loads the jupyter extension.

[greazer]

The jupyter extension should not need to load the Python extension. The dependency isn't supposed to work that way.

[greazer]

Dupe of #4526

[rchiodo]

Not a dupe of #4526.

[rchiodo]

The root cause of this is here:

vscode-jupyter/src/client/datascience/serviceRegistry.ts

Line 220 in d99989e

const isPythonExtensionInstalled = serviceManager.get<IPythonExtensionChecker>(IPythonExtensionChecker);

Maybe there's another way we can determine if the python extension is installed other than calling the getExtension API.

[DonJayamanne]

I think this is how it has always worked, looks like just because the extension is installed we assume it has been actiavted and try to use it (when we try to use this, then we actiavte it if hasn't been activated).

[DonJayamanne]

When i open a typescript notebook, we still activate Python extension (if it is installed) because we're searching for kernels in interpreters.
Not sure i can get around this.
Basically we don't know what kind of notebook the user is dealing with.

E.g. assume the following

• User has python extension installed
• User creates a blank notebook
• Now user goes into kernel picker:
  • How do we know whther user is creating python notebook or not.
  • We need to display kernels in Python interpreters.

I.e. i don't see any way around this.
Thoughts?

@greazer @IanMatthewHuff @rchiodo @DavidKutu @joyceerhl @claudiaregio /cc

[rchiodo]

Notebook seems okay to load the python extension. It just shouldn't load in a directory with markdown files.

[greazer]

One way we could potentially work around this problem is to prompt the user to set a language for the first cell of their notebook before the kernel picker is populated with anything. Right?

Example: Assuming your scenario, the user has a blank notebook with no language set in the first cell.

• User click on the kernel picker. They just see a prompt describing the situation. Could be modal or not modal. Or perhaps the popup for the kernel picker just says "Choose a language for the first cell to choose a kernel"

[IanMatthewHuff]

I dunno, still seems like if I was a Julia or R user that I wouldn't want the python extension activated just for opening a notebook. Creating a blank notebook could save a default language to use for new notebooks. Then only activate and search for python language notebooks?

[DonJayamanne]

User click on the kernel picker. They just see a prompt describing the situation. Could be modal or not modal. Or perhaps the popup for the kernel picker just says "Choose a language for the first cell to choose a kernel"

Not sure i like this.
I'm with @rchiodo, its ok for notebooks.
I.e. my argument is, if the user opens a notebook and they have python extension installed, then I its ok to activate Python extension.

Having to get the user to first select a language then the kernel feels like too many steps.

[DonJayamanne]

Creating a blank notebook could save a default language to use for new notebooks. Then only activate and search for python language notebooks?

Sure, but what if i now want to change the kernel to a Python kernel? At this point we won't be displaying all the python interpreters as the Python extension hasn't been actiavted.

I think its ok to activate the python extension.
The crux of the problem is Python extnesion is displaying prompts upon activation and fixing that would not cause issues. I.e. if we didn't have popups would this be an issue, i don't think so.

I'd say, if user installed Python extnesion, then its ok to activate.

[DonJayamanne]

Python extenion should display prompts like select a pytohn interpreetr only when user attempts to do somethign with python, editing a file, or running some python command that requires python.

Else I don't see the need for the prompt just because the extension actiavted. But that's an issue at their end.

[greazer]

Ok. I think I see what you're saying Don. Here's a summary...

• If the user does not have the Python extension installed and a user opens a blank or non-Python notebook, then they will not be prompted to install the Python extension (let alone have it activate) Question: what will the user see if they click on the kernel picker in this state?
• If the user does not have the Python extension installed and a user opens a Python notebook OR the user chooses Python as the language for the first cell, they WILL be prompted to install the Python extension.
• If the user has the Python extension installed and a user opens a non-Python notebook, then the Python extension will be activated (as silently and quickly as possible) such that we can show a list of Python interpreters/kernels in addition to other jupyter kernels we find when the user clicks on the kernel picker.
• If the user has the Python extension installed and a user opens a Python notebook, then the Python extension is activated and kernel picker displays everything as we normally do today.

Is this complete? Do I have it right? Not sure I think it's the right answer yet, though.

[DonJayamanne]

This has been done, but we need tests for this.

[DonJayamanne]

his has been done, but we need tests for this.

We've regressed as a result of the changes for Kernel Push (tests really need to be added for this so we don't regress).
More details here #6185 (comment)

[greazer]

It seems ok to activate the python extension if there are python cells in it. This just needs to e thought through with our getting started investigation.

[rchiodo]

I believe the test would be:

• create untitled notebook
• verify python extension does not load

But how does it create the notebook controllers then?

[rchiodo]

Actually that seems like it should load the python extension. As long as it doesn't prevent opening (which it currently doesn't).

I don't think there's a scenario to test for here then.