starship/src/modules/username.rs

use super::{Context, Module, RootModuleConfig};

use crate::configs::username::UsernameConfig;
use crate::formatter::StringFormatter;
use crate::utils;

/// Creates a module with the current user's username
///
/// Will display the username if any of the following criteria are met:
///     - The current user isn't the same as the one that is logged in (`$LOGNAME` != `$USER`)
///     - The current user is root (UID = 0)
///     - The user is currently connected as an SSH session (`$SSH_CONNECTION`)
pub fn module<'a>(context: &'a Context) -> Option<Module<'a>> {
    let user = context.get_env("USER");
    let logname = context.get_env("LOGNAME");
    let ssh_connection = context.get_env("SSH_CONNECTION");

    const ROOT_UID: Option<u32> = Some(0);
    let user_uid = get_uid();

    let mut module = context.new_module("username");
    let config: UsernameConfig = UsernameConfig::try_load(module.config);

    if user != logname || ssh_connection.is_some() || user_uid == ROOT_UID || config.show_always {
        let username = user?;
        let parsed = StringFormatter::new(config.format).and_then(|formatter| {
            formatter
                .map_style(|variable| match variable {
                    "style" => {
                        let module_style = match user_uid {
                            Some(0) => config.style_root,
                            _ => config.style_user,
                        };
                        Some(Ok(module_style))
                    }
                    _ => None,
                })
                .map(|variable| match variable {
                    "user" => Some(Ok(&username)),
                    _ => None,
                })
                .parse(None)
        });
        module.set_segments(match parsed {
            Ok(segments) => segments,
            Err(error) => {
                log::warn!("Error in module `username`:\n{}", error);
                return None;
            }
        });

        Some(module)
    } else {
        None
    }
}

fn get_uid() -> Option<u32> {
    utils::exec_cmd("id", &["-u"])?
        .stdout
        .trim()
        .parse::<u32>()
        .ok()
}

#[cfg(test)]
mod tests {
    use crate::test::ModuleRenderer;
    use ansi_term::Color;
    use std::io;

    // TODO: Add tests for if root user (UID == 0)
    // Requires mocking

    #[test]
    fn no_env_variables() -> io::Result<()> {
        let actual = ModuleRenderer::new("username").collect();
        let expected = None;

        assert_eq!(expected, actual);
        Ok(())
    }

    #[test]
    fn logname_equals_user() -> io::Result<()> {
        let actual = ModuleRenderer::new("username")
            .env("LOGNAME", "astronaut")
            .env("USER", "astronaut")
            .collect();
        let expected = None;

        assert_eq!(expected, actual);
        Ok(())
    }

    #[test]
    fn ssh_wo_username() -> io::Result<()> {
        // SSH connection w/o username
        let actual = ModuleRenderer::new("username")
            .env("SSH_CONNECTION", "192.168.223.17 36673 192.168.223.229 22")
            .collect();
        let expected = None;

        assert_eq!(expected, actual);
        Ok(())
    }

    #[test]
    fn current_user_not_logname() -> io::Result<()> {
        let actual = ModuleRenderer::new("username")
            .env("LOGNAME", "astronaut")
            .env("USER", "cosmonaut")
            .collect();
        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("cosmonaut")));

        assert_eq!(expected, actual);
        Ok(())
    }

    #[test]
    fn ssh_connection() -> io::Result<()> {
        let actual = ModuleRenderer::new("username")
            .env("USER", "astronaut")
            .env("SSH_CONNECTION", "192.168.223.17 36673 192.168.223.229 22")
            .collect();
        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("astronaut")));

        assert_eq!(expected, actual);
        Ok(())
    }

    #[test]
    fn show_always() -> io::Result<()> {
        let actual = ModuleRenderer::new("username")
            .env("USER", "astronaut")
            .config(toml::toml! {
                [username]
                show_always = true
            })
            .collect();
        let expected = Some(format!("via {} ", Color::Yellow.bold().paint("astronaut")));

        assert_eq!(expected, actual);
        Ok(())
    }
}