When no kernel is selected, notebook.cell.executeAndSelectBelow cell insertion dismisses kernel picker

[claudiaregio]

Environment data

• VS Code version: 1.58.0-insider
• Jupyter Extension version (available under the Extensions sidebar): v2021.8.993044620
• Python Extension version (available under the Extensions sidebar): v2021.6.944021595
• OS (Windows | Mac | Linux distro) and version: Windows

Steps to Reproduce:

1. Create new notebook
2. Put something in first cell
3. Use Shift + Enter shortcut to run

Expected behavior

To be prompted for a kernel and run after selection, then focus moves to next cell

Actual behavior

Focus moves to the next cell, I am not prompted to pick a kernel as none is selected for a new notebook.
Have to put focus back on the first cell and try shift + enter again

*Note: This does not occur if I open an existing notebook that has not been seen by VS Code before

[greazer]

Let's take a look as we contribute shift-enter which just calls VS Code's command. It should popup the kernel.

[joyceerhl]

@claudiaregio I believe what's happening here is that the kernel picker comes up and then immediately disappears because the inserting a new cell into the notebook steals focus from the kernel picker. Can you confirm if that's what you're seeing too?

shift+enter keybinding maps directly to notebook.cell.executeAndSelectBelow, and if no kernel is selected the kernel picker should be appearing:

vscode/src/vs/workbench/contrib/notebook/browser/notebookEditorKernelManager.ts

Lines 38 to 42 in 3c9e29f

	let kernel = this.getSelectedOrSuggestedKernel(notebook);
	if (!kernel) {
	await this._commandService.executeCommand(SELECT_KERNEL_ID);
	kernel = this.getSelectedOrSuggestedKernel(notebook);
	}

[joyceerhl]

The workspace edit to insert a new cell if the executed cell was the last one in the notebook dismisses the kernel picker. If there is already a cell below, focusing that cell doesn't dismiss the kernel picker.

That is why it looks like shift+enter doesn't work the first time: on first shift+enter, there is no cell below, so we insert a cell; if you set focus back to the first cell and try again, there's already a cell below, so it just focuses that one.

[joyceerhl]

@roblourens I see that we intentionally defer evaluating runCell until after the next cell has been inserted (if necessary) and focused: #99156 Is there a way to ensure that inserting a notebook cell doesn't dismiss the kernel picker?

[claudiaregio]

@joyceerhl Yes, I see a really fast flash