Expose a terminal's creation options as API

[DonJayamanne]

Right now when a terminal is created the onDidOpenTerminal event fires providing the ref to the terminal created.

This information is crucial for the Python Extension when activating the Python Environment in the terminal.

Note: Each workspace folder can have different python environments, hence the workspace folder Uri is necessary when identifying the python environment that needs to be activated.

Suggestion: Add workspaceUr or cwd to the Terminal object.

[Tyriar]

Well terminals aren't bound to workspaces and we can't expose a dynamic cwd, how about this?

export interface Terminal {
  readonly initialCwd: string;
}

[DonJayamanne]

That's perfect, yes I agree with your comment.

[Tyriar]

@DonJayamanne if #46696 worked in multi-root workspaces would that also fix the problem?

[DonJayamanne]

Unfortunately no.

[Tyriar]

@DonJayamanne you need to do more than just set the python version on the path, like run some script to set up virtual env or something?

[DonJayamanne]

like run some script to set up virtual env or something?

Yes, thats right.

[Tyriar]

Adding to October for discussion, this won't be implemented in October.

[Tyriar]

I discussed this at the API meeting today, instead of exposing an initialCwd property on Terminal we could make it more generic and just expose the options object used to create the terminal:

export interface Terminal {
	/**
	 * The object used to initialize the terminal, this is useful for things like detecting the
	 * shell type of shells not launched by the extension or detecting what folder the shell was
	 * launched in.
	 */
	readonly creationOptions: Readonly<TerminalOptions | ExtensionTerminalOptions>;
}

[Tyriar]

We should use Readonly<...>, probably be a good idea to freeze the object behind the scenes too

[Tyriar]

@DonJayamanne I'd like some feedback/validation before promoting this to stable, if the idea is validated then we can look at promoting it to stable for December.

[DonJayamanne]

Woo hoo. Perfect. Validated, thanks

[Tyriar]

To verify:

1. Create an extension that logs creationOptions for each Terminal in vscode.window.terminals whenever a terminal is created via onDidOpenTerminal
2. Create some terminals using normal means, createTerminal and another extension and verify creationOptions looks correct.

[connor4312]

I tried this. I do see the creation options, but the cwd is undefined when creating a terminal via the + button, in both single root and multiroot workspaces. I would expect this to be set to the relevant workspace folder.

[Tyriar]

@connor4312 are you sure it's not working in multi-root workspaces? It's undefined in single root workspaces for me, which means open the default cwd, but for multi-root it always sets it as a URI? Are you by chance using this command?

It is expected to come through as undefined for that as well.

[connor4312]

Okay, if that's expected then I think we're good 🙂

[Tyriar]

Thanks, it is an important edge case for extensions to consider, my hope is that it's understood as those terminals were created just like a call to createTerminal when cwd is undefined.