install python modules in Terminal when python.installModulesInTerminal enabled

[sharon-wang]

• addresses Cannot see failures when installing ipykernel #5506
• adds a new command python.installModulesInTerminal, that, when enabled, forces python installations to occur in the Terminal
  • this option is disabled by default
• passes an otherwise unused cancellation token to the terminal service, which makes it so that the terminal execution must complete before the promise resolves
  • This might mean that we can opt to use the Terminal (and pass a cancellation token) in the places where we have the comment

          // Using a process to install modules avoids using the terminal service,
          // which has issues waiting for the outcome of the install.

  • positron/extensions/positron-python/src/client/common/terminal/types.ts

    Line 44 in 54cbc06

    * @param {CancellationToken} [cancel] If provided, then wait till the command is executed in the terminal.

QA Notes

When python.installModulesInTerminal is enabled, any flow that passes through the installModule() method should run the install command in a Terminal visible to the user. When the option is not enabled, python module installations should occur in the background, invisible to the user.

Project Wizard

1. Create a Python or Jupyter project with Venv
2. One of the new project initialization tasks should kick off the ipykernel install in a Terminal

Command Prompt

1. Run the command Python: Create Environment
2. Start the newly created interpreter
3. Accept the ipykernel install
4. See ipykernel install in a Terminal

Select interpreter that does not have ipykernel

1. Select an interpreter from the Interpreter Dropdown or use the Python: Select Interpreter command that does not already have ipykernel installed
2. Accept the ipykernel install
3. See ipykernel install in a Terminal

[jmcphers]

LGTM; confirmed that turning on this new setting lets me see the installs in a Terminal.

[seeM]

Code changes LGTM!