Feature Request: Make the PowerShell Extension profile available as a profile.

Prerequisites

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Summary

Hello,

I am not good enough with TypeScript/JavaScript to say that I would be able to help actually implement it, but I would like to help if possible.

Currently the extension creates a terminal window and passes the startup scripts to the terminal in code. I would like to propose the idea of fully integrating the terminal created by the extension as.

This would add the following benefits:

• Users would the ability to have the PowerShell Extension show as one or more profiles in the profile selector.
• Users can select the PowerShell Extension profile as their default profile in the profile selector.
• Users can pass arguments to the PowerShell profile at runtime.
• Make it easier to work with sessions.
• Existing command workbench.action.terminal.relaunch could be used in place of PowerShell.RestartSession

Users would be able to configure the profile by adding the profile Json to their settings.

{
	"terminal.integrated.profiles.windows": {
		"PowerShell Extension": {
			"title": "PowerShell Extension",
			"env": {
				"${env:Example}": "Test"
			},
			"overrideName": false,
			"args": [],
			"id": "ms-vscode.powershell.PowerShell-Extension",
			"extensionIdentifier": "ms-vscode.powershell"
		}
	}
}

Proposed Design

The way this could be implemented is by adding in the code to have the extension be a terminal provider. Example below taken from the VSCode API reference.

contributes.terminal

Contribute a terminal profile to VS Code, allowing extensions to handle the creation of the profiles. When defined, the profile should appear when creating the terminal profile.

{
  "activationEvents": [
    "onTerminalProfile:my-ext.terminal-profile"
  ],
  "contributes": {
    "terminal": {
      "profiles": [
        {
          "title": "Profile from extension",
          "id": "my-ext.terminal-profile"
        }
      ]
    },
  }
}

When defined, the profile will show up in the terminal profile selector. When activated, handle the creation of the profile by returning terminal options:

vscode.window.registerTerminalProfileProvider('my-ext.terminal-profile', {
  provideProfileOptions(token: vscode.CancellationToken): vscode.ProviderResult<vscode.TerminalOptions | vscode.ExtensionTerminalOptions> {
    return {
      name: 'Profile from extension',
      shellPath: 'bash'
    };
  }
});

Start by reading the extension's current terminal creation and startup-script handling, then compare it with VS Code's contributes.terminal and registerTerminalProfileProvider APIs described here. Done means the extension appears in the terminal profile selector, supports configuration and runtime arguments, and can use the standard terminal relaunch flow.