Prepending using shell integration does not work for fish when using starship prompt

[karrtikr]

starship is a customized prompt. Same issue as #205133 (comment) but for fish.

Turns out #206994 was just fixing it for zsh, we should make sure to apply these changes to all shell integration scripts using VSCODE_SHELL_INTEGRATION.

cc/ @Tyriar

Originally reported in microsoft/vscode-python#23110 microsoft/vscode-python#22429

[kahosan]

same problem

[Tyriar]

Turns out just shell integration does not work at all when using starship under fish currently.

[Tyriar]

Shell integration overwrites the prompt completely which replaces our hooks that apply the env changes. To get shell integration working in this case you need to install it manually and disable the setting inside VS Code:

"terminal.integrated.shellIntegration.enabled": false

config.fish:

if status is-interactive
    starship init fish | source

    string match -q "$TERM_PROGRAM" "vscode"
        and . (code-insiders --locate-shell-integration-path fish)
end

The only way to work around this AFAIK is to write files to ~/.config/fish/conf.d/ which is something we don't want to do as it's overstepping our bounds and messing with a user's machine. The onDidChangeTerminalShellIntegration event should never fire when this by default so it should not block EnvironmentVariableCollection-based activation. cc @anthonykim1