Do not attempt to launch any servers in case when Python is not installed

[karrtikr]

Something like:

public async hasInterpreters(): Promise<boolean> {
    const onAddedToCollection = createDeferred();
    // Watch for collection changed events.
    this.api.onChanged(async (e: PythonEnvCollectionChangedEvent) => {
        if (e.new) {
            onAddedToCollection.resolve();
        }
    });
    const initialEnvs = this.api.getEnvs();
    if (initialEnvs.length > 0) {
        return true;
    }
    await Promise.race([onAddedToCollection.promise, this.api.getRefreshPromise()]);
    return this.api.getEnvs().length > 0;
}

can be built off using the proposed discovery API.

[karthiknadig]

@karrtikr @luabud Since this particular issue is there to reduce the number of notifications we pop; do you suggest that we just log this

@karrtikr I don't want this template to have any more knowledge about how the discovery occurs in the python extension. I think a better approach is, this extension asks for interpreter, and gets back undefined if nothing is available. When one becomes available and is selected it will trigger interpreter changed event. that should start the server.

[luabud]

I agree 👍

[karthiknadig]

To Do:

• Use new API to fetch python.
• If python is missing log to output channel.
• If user runs restart command, show notification that python is not selected. With a button to trigger python selection.

[karrtikr]

If user runs restart command, show notification that python is not selected. With a button to trigger python selection.

python.triggerEnvSelection command can be used if no interpreter is returned via the API to trigger a prompt asking to select an interpreter.

[karrtikr]

Can you please link the PRs/commits fixing this in all 4 repositories?

[karrtikr]

We should also add a milestone so these can be verified.

[karthiknadig]

pull requests for the template:
#30
#34

Pull request for pylint:
microsoft/vscode-pylint#147

Pull request for black:
pending

Pull request for isort:
pending

Note that i did create TPI to test some settings which used proposed API. There is no direct way to test the template other than using the pylint, black, isort extensions. I will schedule a mini bug bash for those next week.