par_term/tab/

constructors.rs

//! Tab constructors: `Tab::new`, `Tab::new_from_profile`, and `Tab::new_internal`.
//!
//! Split from `tab/mod.rs` to keep that file under 500 lines. The `Tab` struct
//! definition and `Drop` impl remain in `mod.rs`; all constructor logic lives here.

use super::{Tab, TabInitParams};
use crate::config::Config;
use crate::config::SessionLogFormat;
use crate::pane::{Pane, PaneManager};
use crate::profile::Profile;
use crate::session_logger::{SessionLogger, create_shared_logger};
use crate::tab::activity_state::TabActivityMonitor;
use crate::tab::initial_text::build_initial_text_payload;
use crate::tab::profile_state::TabProfileState;
use crate::tab::scripting_state::TabScriptingState;
use crate::tab::setup::{
    apply_login_shell_flag, build_shell_env, create_base_terminal, get_shell_command,
};
use crate::tab::tmux_state::TabTmuxState;
use par_term_config::TabId;
use par_term_terminal::TerminalManager;
use par_term_terminal::conversion::to_core_restart_policy;
use std::sync::Arc;
use std::sync::atomic::{AtomicBool, AtomicU8};
use tokio::runtime::Runtime;
use tokio::sync::RwLock;

impl Tab {
    /// Shared constructor body called by both `Tab::new()` and `Tab::new_from_profile()`.
    ///
    /// Both public constructors:
    /// 1. Create and configure a `TerminalManager` (divergent: shell command, env, login_shell)
    /// 2. Call this method to handle the identical steps:
    ///    - Coprocess auto-start loop
    ///    - Script auto-start loop
    ///    - Session logging setup
    ///    - `Arc<RwLock<>>` wrapping
    ///    - Initial text scheduling (only when `params.runtime` is `Some`)
    ///    - `Tab` struct construction with all shared default fields
    ///
    /// # Arguments
    /// * `params` — Constructor-specific values (title, working_directory, etc.)
    /// * `terminal` — Fully configured `TerminalManager` with PTY already spawned
    /// * `config` — Global config (used for coprocesses, scripts, and session logging)
    /// * `session_title` — Human-readable title written to the session log file header
    pub(super) fn new_internal(
        params: TabInitParams,
        terminal: TerminalManager,
        config: &Config,
        session_title: String,
    ) -> anyhow::Result<Self> {
        // Sync triggers from config into the core TriggerRegistry
        let trigger_security = terminal.sync_triggers(&config.automation.triggers);

        // Auto-start configured coprocesses via the PtySession's built-in manager
        let mut coprocess_ids = Vec::with_capacity(config.automation.coprocesses.len());
        for coproc_config in &config.automation.coprocesses {
            if coproc_config.auto_start {
                let core_config = par_term_emu_core_rust::coprocess::CoprocessConfig {
                    command: coproc_config.command.clone(),
                    args: coproc_config.args.clone(),
                    cwd: None,
                    env: par_term_terminal::coprocess_env(),
                    copy_terminal_output: coproc_config.copy_terminal_output,
                    restart_policy: to_core_restart_policy(coproc_config.restart_policy),
                    restart_delay_ms: coproc_config.restart_delay_ms,
                };
                match terminal.start_coprocess(core_config) {
                    Ok(id) => {
                        log::info!(
                            "Auto-started coprocess '{}' (id={})",
                            coproc_config.name,
                            id
                        );
                        coprocess_ids.push(Some(id));
                    }
                    Err(e) => {
                        log::warn!(
                            "Failed to auto-start coprocess '{}': {}",
                            coproc_config.name,
                            e
                        );
                        coprocess_ids.push(None);
                    }
                }
            } else {
                coprocess_ids.push(None);
            }
        }

        // Auto-start configured scripts. Runs while `terminal` is still owned
        // here, so the observer registration needs no lock (the `Arc<RwLock<_>>`
        // wrap happens further down).
        let mut scripting = TabScriptingState {
            coprocess_ids,
            trigger_prompt_before_run: trigger_security,
            ..TabScriptingState::default()
        };
        for (index, script_config) in config.automation.scripts.iter().enumerate() {
            if !script_config.should_auto_start() {
                continue;
            }
            match scripting.start_script_at(&terminal, index, script_config) {
                Ok(id) => {
                    log::info!("Auto-started script '{}' (id={})", script_config.name, id);
                    crate::debug_info!(
                        "SCRIPT",
                        "auto-start: '{}' index={} id={}",
                        script_config.name,
                        index,
                        id
                    );
                }
                Err(e) => {
                    log::warn!(
                        "Failed to auto-start script '{}': {}",
                        script_config.name,
                        e
                    );
                    crate::debug_error!(
                        "SCRIPT",
                        "auto-start FAILED for '{}' index={}: {}",
                        script_config.name,
                        index,
                        e
                    );
                }
            }
        }

        // Create shared session logger
        let session_logger = create_shared_logger();

        // Set up session logging if enabled
        if config.session_log.auto_log_sessions {
            let logs_dir = config.logs_dir();

            // SEC-010: Ensure the logs directory exists with owner-only permissions
            // (0o700) so session logs are not world-listable.
            if let Err(e) = std::fs::create_dir_all(&logs_dir) {
                log::warn!("Failed to create logs directory {:?}: {}", logs_dir, e);
            } else {
                #[cfg(unix)]
                {
                    use std::os::unix::fs::PermissionsExt;
                    let _ =
                        std::fs::set_permissions(&logs_dir, std::fs::Permissions::from_mode(0o700));
                }
            }

            let title_with_ts = Some(format!(
                "{} - {}",
                session_title,
                chrono::Local::now().format("%Y-%m-%d %H:%M:%S")
            ));

            match SessionLogger::new(
                config.session_log.session_log_format,
                &logs_dir,
                (config.cols, config.rows),
                title_with_ts,
            ) {
                Ok(mut logger) => {
                    logger.set_redact_passwords(config.session_log.session_log_redact_passwords);
                    if let Err(e) = logger.start() {
                        log::warn!("Failed to start session logging: {}", e);
                    } else {
                        log::info!("Session logging started: {:?}", logger.output_path());

                        // Set up output callback to record PTY output
                        let logger_clone = Arc::clone(&session_logger);
                        terminal.set_output_callback(move |data: &[u8]| {
                            if let Some(ref mut logger) = *logger_clone.lock() {
                                logger.record_output(data);
                            }
                        });

                        *session_logger.lock() = Some(logger);
                    }
                }
                Err(e) => {
                    log::warn!("Failed to create session logger: {}", e);
                }
            }
        }

        let terminal = Arc::new(RwLock::new(terminal));

        // v3 session logs need the graphics store at finalization; hand the
        // logger a handle to the terminal so stop() can run the core lib's
        // graphics-aware export (the store is crate-internal to emu-core).
        if config.session_log.session_log_format == SessionLogFormat::AsciicastV3
            && let Some(ref mut logger) = *session_logger.lock()
        {
            let tm = Arc::clone(&terminal);
            logger.set_v3_exporter(Box::new(move |session| {
                tm.try_read()
                    .ok()
                    .map(|tm| tm.export_session_asciicast_v3(session))
            }));
        }

        // Send initial text after optional delay (only when a runtime is provided)
        if let Some(runtime) = params.runtime
            && let Some(payload) = build_initial_text_payload(
                &config.shell.initial_text,
                config.shell.initial_text_send_newline,
            )
        {
            let delay_ms = config.shell.initial_text_delay_ms;
            let terminal_clone = Arc::clone(&terminal);
            runtime.spawn(async move {
                if delay_ms > 0 {
                    tokio::time::sleep(tokio::time::Duration::from_millis(delay_ms)).await;
                }

                let term = terminal_clone.read().await;
                if let Err(err) = term.write(&payload) {
                    log::warn!("Failed to send initial text: {}", err);
                }
            });
        }

        // Always create a PaneManager with one primary pane that wraps `tab.terminal`
        // (R-32). This eliminates the fallback scroll_state/mouse/bell/cache fields
        // that were used when pane_manager was None (single-pane mode).
        let is_active = Arc::new(AtomicBool::new(false));
        let pane_manager = PaneManager::new_with_existing_terminal(
            Arc::clone(&terminal),
            params.working_directory.clone(),
            Arc::clone(&is_active),
        );

        Ok(Self {
            id: params.id,
            terminal,
            pane_manager: Some(pane_manager),
            title: params.title,
            refresh_task: None,
            working_directory: params.working_directory,
            custom_color: None,
            has_default_title: params.has_default_title,
            user_named: params.user_named,
            activity: TabActivityMonitor::default(),
            session_logger,
            tmux: TabTmuxState::default(),
            detected_hostname: None,
            detected_cwd: None,
            custom_icon: None,
            profile: TabProfileState::default(),
            scripting,
            was_alt_screen: false,
            is_active,
            shutdown_fast: false,
            is_hidden: false,
            cached_modify_other_keys_mode: AtomicU8::new(0),
            cached_application_cursor: AtomicBool::new(false),
            cached_alt_screen_active: AtomicBool::new(false),
            cached_has_tmux_child: AtomicBool::new(false),
        })
    }

    /// Create a new tab with a terminal session
    ///
    /// # Arguments
    /// * `id` - Unique tab identifier
    /// * `tab_number` - Display number for the tab (1-indexed)
    /// * `config` - Terminal configuration
    /// * `runtime` - Tokio runtime for async operations
    /// * `working_directory` - Optional working directory to start in
    /// * `grid_size` - Optional (cols, rows) override. When provided, uses these
    ///   dimensions instead of config.cols/rows. This ensures the shell starts
    ///   with the correct dimensions when the renderer has already calculated
    ///   the grid size accounting for tab bar height.
    pub fn new(
        id: TabId,
        tab_number: usize,
        config: &Config,
        runtime: Arc<Runtime>,
        working_directory: Option<String>,
        grid_size: Option<(usize, usize)>,
    ) -> anyhow::Result<Self> {
        // Create and configure terminal
        let (mut terminal, _, _) = create_base_terminal(config, grid_size)?;

        // Determine working directory:
        // 1. If explicitly provided (e.g., from tab_inherit_cwd), use that
        // 2. Otherwise, use the configured startup directory based on mode
        let effective_startup_dir = config.get_effective_startup_directory();
        let work_dir = working_directory
            .as_deref()
            .or(effective_startup_dir.as_deref());

        // Get shell command and apply login shell flag
        let (shell_cmd, mut shell_args) = get_shell_command(config);
        apply_login_shell_flag(&mut shell_args, config);

        let shell_args_deref = shell_args.as_deref();
        let shell_env = build_shell_env(config.shell.shell_env.as_ref());
        terminal.spawn_custom_shell_with_dir(
            &shell_cmd,
            shell_args_deref,
            work_dir,
            shell_env.as_ref(),
        )?;

        // Generate initial title based on current tab count, not unique ID
        let title = format!("Tab {}", tab_number);

        Self::new_internal(
            TabInitParams {
                id,
                title,
                has_default_title: true,
                user_named: false,
                working_directory: working_directory
                    .or_else(|| config.shell.working_directory.clone()),
                runtime: Some(runtime),
            },
            terminal,
            config,
            format!("Tab {}", tab_number),
        )
    }

    /// Create a new tab from a profile configuration
    ///
    /// The profile can override:
    /// - Working directory
    /// - Command and arguments (instead of default shell)
    /// - Tab name
    ///
    /// If a profile specifies a command, it always runs from the profile's working
    /// directory (or config default if unset).
    ///
    /// # Arguments
    /// * `id` - Unique tab identifier
    /// * `config` - Terminal configuration
    /// * `_runtime` - Tokio runtime (unused: profile tabs don't send initial text)
    /// * `profile` - Profile configuration to use
    /// * `grid_size` - Optional (cols, rows) override for initial terminal size
    ///
    /// # Unique logic vs `Tab::new()`
    /// This constructor's divergent logic (not shared with `Tab::new()` via `new_internal`):
    /// - SSH command detection (`profile.ssh_command_args()`)
    /// - Per-profile `login_shell` override (takes precedence over `config.login_shell`)
    /// - Per-profile `SHELL` env-var injection when `profile.shell` is set
    /// - Title derived from `profile.tab_name` → `profile.name` (not "Tab N")
    /// - Profile tabs do NOT send `config.initial_text` on startup
    pub fn new_from_profile(
        id: TabId,
        config: &Config,
        _runtime: Arc<Runtime>,
        profile: &Profile,
        grid_size: Option<(usize, usize)>,
    ) -> anyhow::Result<Self> {
        // Create and configure terminal
        let (mut terminal, _, _) = create_base_terminal(config, grid_size)?;

        // Determine working directory: profile overrides config startup directory
        let effective_startup_dir = config.get_effective_startup_directory();
        let work_dir = profile
            .working_directory
            .as_deref()
            .or(effective_startup_dir.as_deref());

        // Determine command and args with priority:
        // 0. profile.ssh_host → build ssh command with user/port/identity args
        // 1. profile.command → use as-is (non-shell commands like tmux, ssh)
        // 2. profile.shell → use as shell, apply login_shell logic
        // 3. neither → fall back to global config shell / $SHELL
        let is_ssh_profile = profile.ssh_host.is_some();
        let (shell_cmd, mut shell_args) = if let Some(ssh_args) = profile.ssh_command_args() {
            ("ssh".to_string(), Some(ssh_args))
        } else if let Some(ref cmd) = profile.command {
            (cmd.clone(), profile.command_args.clone())
        } else if let Some(ref shell) = profile.shell {
            (shell.clone(), None)
        } else {
            get_shell_command(config)
        };

        // Apply login shell flag when using a shell (not a custom command or SSH profile).
        // Per-profile login_shell overrides global config.login_shell.
        if profile.command.is_none() && !is_ssh_profile {
            let use_login_shell = profile.login_shell.unwrap_or(config.shell.login_shell);
            if use_login_shell {
                let args = shell_args.get_or_insert_with(Vec::new);
                #[cfg(not(target_os = "windows"))]
                if !args.iter().any(|a| a == "-l" || a == "--login") {
                    args.insert(0, "-l".to_string());
                }
            }
        }

        let shell_args_deref = shell_args.as_deref();
        let mut shell_env = build_shell_env(config.shell.shell_env.as_ref());

        // When a profile specifies a shell, set the SHELL env var so child
        // processes (and $SHELL) reflect the selected shell, not the login shell.
        if profile.command.is_none()
            && let Some(ref shell_path) = profile.shell
            && let Some(ref mut env) = shell_env
        {
            env.insert("SHELL".to_string(), shell_path.clone());
        }

        terminal.spawn_custom_shell_with_dir(
            &shell_cmd,
            shell_args_deref,
            work_dir,
            shell_env.as_ref(),
        )?;

        // Generate title: use profile tab_name or profile name
        let title = profile
            .tab_name
            .clone()
            .unwrap_or_else(|| profile.name.clone());

        let working_directory = profile
            .working_directory
            .clone()
            .or_else(|| config.shell.working_directory.clone());

        // Session log title uses profile name (Tab::new uses "Tab N")
        let session_title = profile.name.clone();

        Self::new_internal(
            TabInitParams {
                id,
                title,
                has_default_title: false, // Profile-created tabs have explicit names
                user_named: profile.tab_name.is_some(),
                working_directory,
                runtime: None, // Profile tabs don't send initial_text
            },
            terminal,
            config,
            session_title,
        )
    }

    /// Create a new tab wrapping an existing `Pane` (e.g., from a promote operation).
    ///
    /// The pane's PTY, scroll state, and session logger are preserved.
    /// No new shell is spawned — the pane's terminal keeps running.
    /// The tab shares the pane's `Arc<RwLock<TerminalManager>>` as its primary terminal.
    pub fn new_from_pane(
        id: TabId,
        pane: Pane,
        _config: &Config,
        _runtime: Arc<Runtime>,
        tab_number: usize,
    ) -> Self {
        // Clone the pane's terminal Arc as the tab's primary terminal
        let terminal = Arc::clone(&pane.terminal);
        let is_active = Arc::clone(&pane.is_active);
        let session_logger = Arc::clone(&pane.session_logger);

        // Create a PaneManager with this pane as the single root
        let pane_manager = PaneManager::new_with_pane(pane);

        let title = format!("Tab {}", tab_number);

        Self {
            id,
            terminal,
            pane_manager: Some(pane_manager),
            title,
            refresh_task: None,
            working_directory: None,
            custom_color: None,
            has_default_title: true,
            user_named: false,
            activity: TabActivityMonitor::default(),
            session_logger,
            tmux: TabTmuxState::default(),
            detected_hostname: None,
            detected_cwd: None,
            custom_icon: None,
            profile: TabProfileState::default(),
            scripting: TabScriptingState::default(),
            was_alt_screen: false,
            is_active,
            shutdown_fast: false,
            is_hidden: false,
            cached_modify_other_keys_mode: AtomicU8::new(0),
            cached_application_cursor: AtomicBool::new(false),
            cached_alt_screen_active: AtomicBool::new(false),
            cached_has_tmux_child: AtomicBool::new(false),
        }
    }
}

/// Minimal stub for use in unit tests (no PTY, no runtime).
#[cfg(test)]
impl Tab {
    pub(crate) fn new_stub(id: TabId, tab_number: usize) -> Self {
        use crate::session_logger::create_shared_logger;

        // Create a dummy TerminalManager without spawning a shell
        let terminal =
            TerminalManager::new_with_scrollback(80, 24, 100).expect("stub terminal creation");
        let terminal = Arc::new(RwLock::new(terminal));
        let is_active = Arc::new(AtomicBool::new(false));
        let pane_manager = PaneManager::new_with_existing_terminal(
            Arc::clone(&terminal),
            None,
            Arc::clone(&is_active),
        );
        Self {
            id,
            terminal,
            pane_manager: Some(pane_manager),
            title: format!("Tab {}", tab_number),
            refresh_task: None,
            working_directory: None,
            custom_color: None,
            has_default_title: true,
            user_named: false,
            activity: TabActivityMonitor::default(),
            session_logger: create_shared_logger(),
            tmux: TabTmuxState::default(),
            detected_hostname: None,
            detected_cwd: None,
            custom_icon: None,
            profile: TabProfileState::default(),
            scripting: TabScriptingState::default(),
            was_alt_screen: false,
            is_active,
            shutdown_fast: false,
            is_hidden: false,
            cached_modify_other_keys_mode: AtomicU8::new(0),
            cached_application_cursor: AtomicBool::new(false),
            cached_alt_screen_active: AtomicBool::new(false),
            cached_has_tmux_child: AtomicBool::new(false),
        }
    }
}

/// Regression tests for script auto-start (issue #220).
///
/// `auto_start` was documented as spawning a script at tab creation but was
/// never wired up — only the Settings UI start button could launch a script.
/// These drive the real `new_internal` auto-start loop against a terminal that
/// has no shell spawned, so they run without a PTY on every supported platform.
#[cfg(test)]
mod auto_start_tests {
    use super::*;
    use crate::config::AutomationConfig;
    use par_term_config::ScriptConfig;

    /// A command that stays alive reading stdin, so `is_running` is stable for
    /// the duration of the test. `findstr` is the Windows analogue of `cat`:
    /// given a pattern and no file argument it reads stdin until EOF.
    ///
    /// Invoked directly rather than through `cmd.exe /c`: the shell would treat
    /// `^` as its escape character (`findstr ^` fails with "Bad command line"),
    /// and wrapping in a shell would make the real reader a grandchild that
    /// `Child::kill` does not reap.
    #[cfg(unix)]
    const LONG_LIVED: (&str, &[&str]) = ("/bin/cat", &[]);
    #[cfg(windows)]
    const LONG_LIVED: (&str, &[&str]) = ("findstr.exe", &["x"]);

    /// Script config pointing at a long-lived process so `is_running` is stable.
    fn cat_script(name: &str, enabled: bool, auto_start: bool) -> ScriptConfig {
        let (path, args) = LONG_LIVED;
        ScriptConfig {
            name: name.to_string(),
            enabled,
            script_path: path.to_string(),
            args: args.iter().map(|s| s.to_string()).collect(),
            auto_start,
            restart_policy: Default::default(),
            restart_delay_ms: 0,
            subscriptions: Vec::new(),
            env_vars: Default::default(),
            allow_write_text: false,
            prompt_before_write_text: true,
            allow_run_command: false,
            allow_change_config: false,
            write_text_rate_limit: 0,
            run_command_rate_limit: 0,
        }
    }

    fn tab_with_scripts(scripts: Vec<ScriptConfig>) -> Tab {
        let config = Config {
            automation: AutomationConfig {
                scripts,
                ..Default::default()
            },
            ..Config::default()
        };
        let terminal =
            TerminalManager::new_with_scrollback(80, 24, 100).expect("terminal creation");
        Tab::new_internal(
            TabInitParams {
                id: 1,
                title: "Tab 1".to_string(),
                has_default_title: true,
                user_named: false,
                working_directory: None,
                runtime: None,
            },
            terminal,
            &config,
            "Tab 1".to_string(),
        )
        .expect("tab creation")
    }

    #[test]
    fn auto_start_script_is_running_after_tab_creation() {
        let mut tab = tab_with_scripts(vec![cat_script("auto", true, true)]);

        let id = tab
            .scripting
            .script_ids
            .first()
            .copied()
            .flatten()
            .expect("auto_start script must be spawned at tab creation");
        assert!(
            tab.scripting.script_manager.is_running(id),
            "auto-started script process must be alive"
        );
        assert!(
            matches!(tab.scripting.script_forwarders.first(), Some(Some(_))),
            "auto-started script must have an event forwarder registered"
        );
        assert!(
            matches!(tab.scripting.script_observer_ids.first(), Some(Some(_))),
            "auto-started script must be registered as a terminal observer"
        );
    }

    #[test]
    fn script_without_auto_start_is_not_spawned() {
        let tab = tab_with_scripts(vec![cat_script("manual", true, false)]);
        assert!(
            tab.scripting
                .script_ids
                .first()
                .copied()
                .flatten()
                .is_none(),
            "auto_start: false must stay manual-start only"
        );
    }

    #[test]
    fn disabled_script_is_not_spawned() {
        let tab = tab_with_scripts(vec![cat_script("disabled", false, true)]);
        assert!(
            tab.scripting
                .script_ids
                .first()
                .copied()
                .flatten()
                .is_none(),
            "enabled: false must veto auto_start: true"
        );
    }

    #[test]
    fn tracking_state_stays_aligned_with_config_indices() {
        // Per-tab script tracking is indexed by position in `config.scripts`,
        // so skipped entries must leave holes rather than shifting later ones.
        let mut tab = tab_with_scripts(vec![
            cat_script("manual", true, false),
            cat_script("auto", true, true),
        ]);

        assert!(
            tab.scripting
                .script_ids
                .first()
                .copied()
                .flatten()
                .is_none(),
            "index 0 is manual-start and must stay empty"
        );
        let id = tab
            .scripting
            .script_ids
            .get(1)
            .copied()
            .flatten()
            .expect("index 1 has auto_start: true and must be spawned");
        assert!(tab.scripting.script_manager.is_running(id));
    }

    #[test]
    fn no_scripts_configured_leaves_tracking_empty() {
        let tab = tab_with_scripts(Vec::new());
        assert!(tab.scripting.script_ids.is_empty());
        assert!(tab.scripting.script_forwarders.is_empty());
    }

    /// Restarting an index must tear down the previous script first.
    ///
    /// A script that exits on its own leaves its observer registered — only an
    /// explicit stop removes it — so a naive restart would overwrite the
    /// tracking slot and orphan the old forwarder on the terminal, where it
    /// keeps accumulating events into a buffer nobody drains.
    #[test]
    fn restarting_an_index_does_not_orphan_the_previous_observer() {
        let config = cat_script("auto", true, true);
        let mut tab = tab_with_scripts(vec![config.clone()]);

        let first_id = tab
            .scripting
            .script_ids
            .first()
            .copied()
            .flatten()
            .expect("initial auto-start");
        let first_observer = tab.scripting.script_observer_ids[0].expect("initial observer");

        // Restart the same index, as the Settings UI does after a script exits.
        let second_id = {
            let term = tab.terminal.blocking_read();
            tab.scripting
                .start_script_at(&term, 0, &config)
                .expect("restart")
        };

        assert_ne!(first_id, second_id, "restart must spawn a new process");
        assert!(
            !tab.scripting.script_manager.is_running(first_id),
            "the superseded script process must be stopped"
        );

        // `remove_observer` reports whether the id was still registered, so a
        // second removal returning `true` means the restart leaked it.
        let still_registered = {
            let term = tab.terminal.blocking_read();
            term.remove_observer(first_observer)
        };
        assert!(
            !still_registered,
            "restart must unregister the superseded observer, not orphan it"
        );
    }

    /// Stopping a script must leave no observer behind either.
    #[test]
    fn clearing_an_index_unregisters_its_observer() {
        let mut tab = tab_with_scripts(vec![cat_script("auto", true, true)]);

        let observer = tab.scripting.script_observer_ids[0].expect("initial observer");
        {
            let term = tab.terminal.blocking_read();
            tab.scripting.clear_script_at(&term, 0);
        }

        let still_registered = {
            let term = tab.terminal.blocking_read();
            term.remove_observer(observer)
        };
        assert!(
            !still_registered,
            "stop must unregister the script's observer"
        );
        assert!(
            tab.scripting
                .script_ids
                .first()
                .copied()
                .flatten()
                .is_none()
        );
        assert!(matches!(
            tab.scripting.script_forwarders.first(),
            Some(None)
        ));
    }
}