From bb0dad86f81768c8b7d5894acf7cd53bd05d302b Mon Sep 17 00:00:00 2001
From: Ogulcan Celik <ogulcancelik@gmail.com>
Date: Fri, 8 May 2026 15:37:01 +0300
Subject: [PATCH] fix: split panes in target tab without stealing focus

fixes #75
---
 SOCKET_API.md    |  18 +++----
 src/app/api.rs   |  25 +++++++---
 src/app/mod.rs   | 121 +++++++++++++++++++++++++++++++++++++++++++++++
 src/cli.rs       |  28 ++++++++---
 src/workspace.rs |  36 ++++++++++++++
 5 files changed, 206 insertions(+), 22 deletions(-)

diff --git a/SOCKET_API.md b/SOCKET_API.md
index 3baf31e3..dbb2c379 100644
--- a/SOCKET_API.md
+++ b/SOCKET_API.md
@@ -273,7 +273,7 @@ notes:
 - `cwd` is optional
 - if `cwd` is omitted, herdr uses its current working directory and falls back to `/` if needed
 - `focus` is optional in raw socket requests and defaults to `false`
-- the cli wrapper is more ergonomic here: `herdr workspace create` focuses by default unless you pass `--no-focus`
+- the cli wrapper also defaults to no focus; pass `--focus` to switch to the new workspace
 
 example response:
 
@@ -399,7 +399,7 @@ notes:
 - `workspace_id` is optional and defaults to the active workspace
 - `cwd` is optional; if omitted, herdr uses the focused pane cwd in that workspace when available
 - `focus` is optional in raw socket requests and defaults to `false`
-- the cli wrapper focuses by default unless you pass `--no-focus`
+- the cli wrapper also defaults to no focus; pass `--focus` to switch to the new tab
 
 returns `tab_info` for the new tab.
 
@@ -542,7 +542,7 @@ notes:
 - `direction` must be `right` or `down`
 - `cwd` is optional
 - `focus` is optional in raw socket requests and defaults to `false`
-- the cli wrapper is more ergonomic here too: `herdr pane split ...` focuses by default unless you pass `--no-focus`
+- the cli wrapper also defaults to no focus; pass `--focus` to switch to the new pane
 
 returns `pane_info` for the new pane.
 
@@ -918,7 +918,7 @@ workspace commands:
 
 ```text
 herdr workspace list
-herdr workspace create [--cwd PATH] [--label TEXT] [--no-focus]
+herdr workspace create [--cwd PATH] [--label TEXT] [--focus] [--no-focus]
 herdr workspace get <workspace_id>
 herdr workspace focus <workspace_id>
 herdr workspace rename <workspace_id> <label>
@@ -929,7 +929,7 @@ tab commands:
 
 ```text
 herdr tab list [--workspace <workspace_id>]
-herdr tab create [--workspace <workspace_id>] [--cwd PATH] [--label TEXT] [--no-focus]
+herdr tab create [--workspace <workspace_id>] [--cwd PATH] [--label TEXT] [--focus] [--no-focus]
 herdr tab get <tab_id>
 herdr tab focus <tab_id>
 herdr tab rename <tab_id> <label>
@@ -942,7 +942,7 @@ pane commands:
 herdr pane list [--workspace <workspace_id>]
 herdr pane get <pane_id>
 herdr pane read <pane_id> [--source visible|recent|recent-unwrapped] [--lines N] [--raw]
-herdr pane split <pane_id> --direction right|down [--cwd PATH] [--no-focus]
+herdr pane split <pane_id> --direction right|down [--cwd PATH] [--focus] [--no-focus]
 herdr pane close <pane_id>
 herdr pane send-text <pane_id> <text>
 herdr pane send-keys <pane_id> <key> [key ...]
@@ -961,15 +961,15 @@ herdr wait agent-status <pane_id> --status <idle|working|blocked|done|unknown> [
 - `status` prints local client version/protocol, running server version/protocol when reachable, socket path, compatibility, and whether a restart is needed
 - `status server` prints only the running server side; if no server is reachable it exits successfully and prints `status: not running`
 - `status client` prints only the local executable version/protocol and binary path without contacting the server
-- `workspace create` focuses by default; pass `--no-focus` to keep focus where it is
+- `workspace create` keeps focus where it is by default; pass `--focus` to switch to the new workspace
 - `workspace create` without `--label` keeps the default cwd-based workspace naming
 - `workspace create --label` applies the custom workspace name immediately
 - `workspace create` returns `result.workspace`, `result.tab`, and `result.root_pane`
-- `tab create` focuses by default; pass `--no-focus` to keep focus where it is
+- `tab create` keeps focus where it is by default; pass `--focus` to switch to the new tab
 - `tab create` without `--label` keeps the default numbered tab naming
 - `tab create --label` applies the custom tab name immediately
 - `tab create` returns `result.tab` and `result.root_pane`
-- `pane split` focuses the new pane by default; pass `--no-focus` to keep focus on the original pane
+- `pane split` keeps focus where it is by default; pass `--focus` to switch to the new pane
 - `pane read` prints **text**, not json
 - `pane read --source recent-unwrapped` returns recent terminal text with soft wraps joined back together
 - `pane send-text`, `pane send-keys`, and `pane run` print nothing on success
diff --git a/src/app/api.rs b/src/app/api.rs
index e689d89f..ab8058cf 100644
--- a/src/app/api.rs
+++ b/src/app/api.rs
@@ -819,7 +819,6 @@ impl App {
                     })
                     .unwrap();
                 };
-                ws.layout.focus_pane(target_pane_id);
                 let direction = match params.direction {
                     crate::api::schema::SplitDirection::Right => {
                         ratatui::layout::Direction::Horizontal
@@ -828,16 +827,18 @@ impl App {
                         ratatui::layout::Direction::Vertical
                     }
                 };
-                let new_pane_id = match ws.split_focused(
+                let (target_tab_idx, new_pane_id) = match ws.split_pane(
+                    target_pane_id,
                     direction,
                     rows,
                     cols,
                     params.cwd.map(std::path::PathBuf::from),
                     self.state.pane_scrollback_limit_bytes,
                     self.state.host_terminal_theme,
+                    params.focus,
                 ) {
-                    Ok(new_pane_id) => new_pane_id,
-                    Err(err) => {
+                    Some(Ok(result)) => result,
+                    Some(Err(err)) => {
                         return serde_json::to_string(&ErrorResponse {
                             id: request.id,
                             error: ErrorBody {
@@ -847,9 +848,21 @@ impl App {
                         })
                         .unwrap();
                     }
+                    None => {
+                        return serde_json::to_string(&ErrorResponse {
+                            id: request.id,
+                            error: ErrorBody {
+                                code: "pane_not_found".into(),
+                                message: format!("pane {} not found", params.target_pane_id),
+                            },
+                        })
+                        .unwrap();
+                    }
                 };
-                if !params.focus {
-                    ws.layout.focus_pane(target_pane_id);
+                if params.focus {
+                    self.state.switch_workspace(ws_idx);
+                    self.state.switch_tab(target_tab_idx);
+                    self.state.mode = Mode::Terminal;
                 }
                 self.schedule_session_save();
                 let pane = self.pane_info(ws_idx, new_pane_id).unwrap();
diff --git a/src/app/mod.rs b/src/app/mod.rs
index 32e89f0e..1d09230a 100644
--- a/src/app/mod.rs
+++ b/src/app/mod.rs
@@ -1436,6 +1436,127 @@ mod tests {
         assert!(app.state.should_quit);
     }
 
+    #[tokio::test]
+    async fn pane_split_request_targets_pane_in_background_tab() {
+        let _guard = config_env_lock().lock().unwrap();
+        let original_shell = std::env::var_os("SHELL");
+        std::env::set_var("SHELL", "/usr/bin/true");
+
+        let mut app = test_app();
+        let mut workspace = Workspace::test_new("api-pane-split-background-tab");
+        let active_pane = workspace.tabs[0].root_pane;
+        let background_tab = workspace.test_add_tab(Some("worker"));
+        let target_pane = workspace.tabs[background_tab].root_pane;
+        workspace.switch_tab(background_tab);
+        let background_previous_focus =
+            workspace.test_split(ratatui::layout::Direction::Horizontal);
+        workspace.switch_tab(0);
+        app.state.workspaces = vec![workspace];
+        app.state.active = Some(0);
+        app.state.selected = 0;
+
+        let target_pane_id = app.pane_info(0, target_pane).unwrap().pane_id;
+        let target_tab_id = app.public_tab_id(0, background_tab).unwrap();
+
+        let response = app.handle_api_request(crate::api::schema::Request {
+            id: "req_pane_split_background_tab".into(),
+            method: crate::api::schema::Method::PaneSplit(crate::api::schema::PaneSplitParams {
+                workspace_id: None,
+                target_pane_id,
+                direction: crate::api::schema::SplitDirection::Right,
+                cwd: None,
+                focus: false,
+            }),
+        });
+        let response: serde_json::Value = serde_json::from_str(&response).unwrap();
+
+        assert_eq!(response["result"]["type"], "pane_info");
+        assert_eq!(response["result"]["pane"]["tab_id"], target_tab_id);
+        assert_eq!(response["result"]["pane"]["focused"], false);
+        assert_eq!(app.state.active, Some(0));
+        assert_eq!(app.state.workspaces[0].active_tab, 0);
+        assert_eq!(
+            app.state.workspaces[0].tabs[0].layout.focused(),
+            active_pane
+        );
+        assert_eq!(app.state.workspaces[0].tabs[0].layout.pane_count(), 1);
+        assert_eq!(
+            app.state.workspaces[0].tabs[background_tab]
+                .layout
+                .focused(),
+            background_previous_focus
+        );
+        assert_eq!(
+            app.state.workspaces[0].tabs[background_tab]
+                .layout
+                .pane_count(),
+            3
+        );
+
+        let runtimes: Vec<_> = app.state.workspaces[0]
+            .tabs
+            .iter_mut()
+            .flat_map(|tab| tab.runtimes.drain())
+            .collect();
+        for (pane_id, runtime) in runtimes {
+            runtime.shutdown(pane_id);
+        }
+        match original_shell {
+            Some(value) => std::env::set_var("SHELL", value),
+            None => std::env::remove_var("SHELL"),
+        }
+    }
+
+    #[tokio::test]
+    async fn pane_split_request_focuses_new_pane_when_requested() {
+        let _guard = config_env_lock().lock().unwrap();
+        let original_shell = std::env::var_os("SHELL");
+        std::env::set_var("SHELL", "/usr/bin/true");
+
+        let mut app = test_app();
+        let mut workspace = Workspace::test_new("api-pane-split-focus-background-tab");
+        let background_tab = workspace.test_add_tab(Some("worker"));
+        workspace.switch_tab(0);
+        app.state.workspaces = vec![workspace];
+        app.state.active = Some(0);
+        app.state.selected = 0;
+
+        let target_pane = app.state.workspaces[0].tabs[background_tab].root_pane;
+        let target_pane_id = app.pane_info(0, target_pane).unwrap().pane_id;
+        let target_tab_id = app.public_tab_id(0, background_tab).unwrap();
+
+        let response = app.handle_api_request(crate::api::schema::Request {
+            id: "req_pane_split_focus_background_tab".into(),
+            method: crate::api::schema::Method::PaneSplit(crate::api::schema::PaneSplitParams {
+                workspace_id: None,
+                target_pane_id,
+                direction: crate::api::schema::SplitDirection::Right,
+                cwd: None,
+                focus: true,
+            }),
+        });
+        let response: serde_json::Value = serde_json::from_str(&response).unwrap();
+
+        assert_eq!(response["result"]["type"], "pane_info");
+        assert_eq!(response["result"]["pane"]["tab_id"], target_tab_id);
+        assert_eq!(response["result"]["pane"]["focused"], true);
+        assert_eq!(app.state.active, Some(0));
+        assert_eq!(app.state.workspaces[0].active_tab, background_tab);
+
+        let runtimes: Vec<_> = app.state.workspaces[0]
+            .tabs
+            .iter_mut()
+            .flat_map(|tab| tab.runtimes.drain())
+            .collect();
+        for (pane_id, runtime) in runtimes {
+            runtime.shutdown(pane_id);
+        }
+        match original_shell {
+            Some(value) => std::env::set_var("SHELL", value),
+            None => std::env::remove_var("SHELL"),
+        }
+    }
+
     #[test]
     fn pane_close_request_closes_only_the_target_tab_when_other_tabs_exist() {
         let mut app = test_app();
diff --git a/src/cli.rs b/src/cli.rs
index 1260ee6f..dcc2537c 100644
--- a/src/cli.rs
+++ b/src/cli.rs
@@ -475,7 +475,7 @@ fn workspace_list(args: &[String]) -> std::io::Result<i32> {
 
 fn workspace_create(args: &[String]) -> std::io::Result<i32> {
     let mut cwd = None;
-    let mut focus = true;
+    let mut focus = false;
     let mut label = None;
 
     let mut index = 0;
@@ -497,6 +497,10 @@ fn workspace_create(args: &[String]) -> std::io::Result<i32> {
                 label = Some(value.clone());
                 index += 2;
             }
+            "--focus" => {
+                focus = true;
+                index += 1;
+            }
             "--no-focus" => {
                 focus = false;
                 index += 1;
@@ -613,7 +617,7 @@ fn tab_list(args: &[String]) -> std::io::Result<i32> {
 fn tab_create(args: &[String]) -> std::io::Result<i32> {
     let mut workspace_id = None;
     let mut cwd = None;
-    let mut focus = true;
+    let mut focus = false;
     let mut label = None;
 
     let mut index = 0;
@@ -643,6 +647,10 @@ fn tab_create(args: &[String]) -> std::io::Result<i32> {
                 label = Some(value.clone());
                 index += 2;
             }
+            "--focus" => {
+                focus = true;
+                index += 1;
+            }
             "--no-focus" => {
                 focus = false;
                 index += 1;
@@ -844,7 +852,7 @@ fn pane_read(args: &[String]) -> std::io::Result<i32> {
 fn pane_split(args: &[String]) -> std::io::Result<i32> {
     let Some(raw_pane_id) = args.first() else {
         eprintln!(
-            "usage: herdr pane split <pane_id> --direction right|down [--cwd PATH] [--no-focus]"
+            "usage: herdr pane split <pane_id> --direction right|down [--cwd PATH] [--focus] [--no-focus]"
         );
         return Ok(2);
     };
@@ -852,7 +860,7 @@ fn pane_split(args: &[String]) -> std::io::Result<i32> {
     let pane_id = normalize_pane_id(raw_pane_id);
     let mut direction = None;
     let mut cwd = None;
-    let mut focus = true;
+    let mut focus = false;
 
     let mut index = 1;
     while index < args.len() {
@@ -873,6 +881,10 @@ fn pane_split(args: &[String]) -> std::io::Result<i32> {
                 cwd = Some(value.clone());
                 index += 2;
             }
+            "--focus" => {
+                focus = true;
+                index += 1;
+            }
             "--no-focus" => {
                 focus = false;
                 index += 1;
@@ -1403,7 +1415,7 @@ fn print_status_help() {
 fn print_workspace_help() {
     eprintln!("herdr workspace commands:");
     eprintln!("  herdr workspace list");
-    eprintln!("  herdr workspace create [--cwd PATH] [--label TEXT] [--no-focus]");
+    eprintln!("  herdr workspace create [--cwd PATH] [--label TEXT] [--focus] [--no-focus]");
     eprintln!("  herdr workspace get <workspace_id>");
     eprintln!("  herdr workspace focus <workspace_id>");
     eprintln!("  herdr workspace rename <workspace_id> <label>");
@@ -1414,7 +1426,7 @@ fn print_tab_help() {
     eprintln!("herdr tab commands:");
     eprintln!("  herdr tab list [--workspace <workspace_id>]");
     eprintln!(
-        "  herdr tab create [--workspace <workspace_id>] [--cwd PATH] [--label TEXT] [--no-focus]"
+        "  herdr tab create [--workspace <workspace_id>] [--cwd PATH] [--label TEXT] [--focus] [--no-focus]"
     );
     eprintln!("  herdr tab get <tab_id>");
     eprintln!("  herdr tab focus <tab_id>");
@@ -1427,7 +1439,9 @@ fn print_pane_help() {
     eprintln!("  herdr pane list [--workspace <workspace_id>]");
     eprintln!("  herdr pane get <pane_id>");
     eprintln!("  herdr pane read <pane_id> [--source visible|recent|recent-unwrapped] [--lines N] [--raw]");
-    eprintln!("  herdr pane split <pane_id> --direction right|down [--cwd PATH] [--no-focus]");
+    eprintln!(
+        "  herdr pane split <pane_id> --direction right|down [--cwd PATH] [--focus] [--no-focus]"
+    );
     eprintln!("  herdr pane close <pane_id>");
     eprintln!("  herdr pane send-text <pane_id> <text>");
     eprintln!("  herdr pane send-keys <pane_id> <key> [key ...]");
diff --git a/src/workspace.rs b/src/workspace.rs
index e429ec10..f9fb0493 100644
--- a/src/workspace.rs
+++ b/src/workspace.rs
@@ -244,6 +244,42 @@ impl Workspace {
         Ok(new_id)
     }
 
+    pub fn split_pane(
+        &mut self,
+        pane_id: PaneId,
+        direction: Direction,
+        rows: u16,
+        cols: u16,
+        cwd: Option<PathBuf>,
+        scrollback_limit_bytes: usize,
+        host_terminal_theme: crate::terminal_theme::TerminalTheme,
+        focus_new_pane: bool,
+    ) -> Option<std::io::Result<(usize, PaneId)>> {
+        let tab_idx = self.find_tab_index_for_pane(pane_id)?;
+        let tab = &mut self.tabs[tab_idx];
+        let previous_focus = tab.layout.focused();
+        tab.layout.focus_pane(pane_id);
+        let new_id = match tab.split_focused(
+            direction,
+            rows,
+            cols,
+            cwd,
+            scrollback_limit_bytes,
+            host_terminal_theme,
+        ) {
+            Ok(new_id) => new_id,
+            Err(err) => {
+                tab.layout.focus_pane(previous_focus);
+                return Some(Err(err));
+            }
+        };
+        if !focus_new_pane {
+            tab.layout.focus_pane(previous_focus);
+        }
+        self.register_new_pane(new_id);
+        Some(Ok((tab_idx, new_id)))
+    }
+
     /// Close the focused pane. Returns true if the workspace should close.
     pub fn close_focused(&mut self) -> bool {
         let pane_count = self