feat(layouts): global cwd (#1798)

* feat(layouts): allow defining a global cwd

* feat(layouts): allow passing global cwd from cli

* style(fmt): rustfmt

* fix(layouts): error on mixed cwd and pane children

22 files changed, 1048 insertions, 138 deletions

diff --git a/zellij-server/src/os_input_output.rs b/zellij-server/src/os_input_output.rs
index 9d720c717..7d83085fc 100644
--- a/zellij-server/src/os_input_output.rs
+++ b/zellij-server/src/os_input_output.rs
@@ -140,8 +140,14 @@ fn handle_openpty(
             let cmd = cmd.clone();
             let command = &mut Command::new(cmd.command);
             if let Some(current_dir) = cmd.cwd {
-                if current_dir.exists() {
+                if current_dir.exists() && current_dir.is_dir() {
                     command.current_dir(current_dir);
+                } else {
+                    // TODO: propagate this to the user
+                    log::error!(
+                        "Failed to set CWD for new pane. {} does not exist or is not a folder",
+                        current_dir.display()
+                    );
                 }
             }
             command
diff --git a/zellij-server/src/pty.rs b/zellij-server/src/pty.rs
index 9df221ce3..84088b951 100644
--- a/zellij-server/src/pty.rs
+++ b/zellij-server/src/pty.rs
@@ -364,11 +364,11 @@ impl Pty {
             default_editor,
         }
     }
-    pub fn get_default_terminal(&self) -> TerminalAction {
+    pub fn get_default_terminal(&self, cwd: Option<PathBuf>) -> TerminalAction {
         TerminalAction::RunCommand(RunCommand {
             args: vec![],
             command: PathBuf::from(env::var("SHELL").expect("Could not find the SHELL variable")),
-            cwd: None, // this should be filled by the calling function, eg. spawn_terminal
+            cwd, // note: this might also be filled by the calling function, eg. spawn_terminal
             hold_on_close: false,
         })
     }
@@ -400,12 +400,12 @@ impl Pty {
         let terminal_action = match client_or_tab_index {
             ClientOrTabIndex::ClientId(client_id) => {
                 let mut terminal_action =
-                    terminal_action.unwrap_or_else(|| self.get_default_terminal());
+                    terminal_action.unwrap_or_else(|| self.get_default_terminal(None));
                 self.fill_cwd(&mut terminal_action, client_id);
                 terminal_action
             },
             ClientOrTabIndex::TabIndex(_) => {
-                terminal_action.unwrap_or_else(|| self.get_default_terminal())
+                terminal_action.unwrap_or_else(|| self.get_default_terminal(None))
             },
         };
         let hold_on_close = match &terminal_action {
@@ -454,7 +454,7 @@ impl Pty {
         default_shell: Option<TerminalAction>,
         client_id: ClientId,
     ) {
-        let mut default_shell = default_shell.unwrap_or_else(|| self.get_default_terminal());
+        let mut default_shell = default_shell.unwrap_or_else(|| self.get_default_terminal(None));
         self.fill_cwd(&mut default_shell, client_id);
         let extracted_run_instructions = layout.extract_run_instructions();
         let mut new_pane_pids: Vec<(u32, Option<RunCommand>, Result<RawFd, SpawnTerminalError>)> =
@@ -513,6 +513,29 @@ impl Pty {
                         },
                     }
                 },
+                Some(Run::Cwd(cwd)) => {
+                    let shell = self.get_default_terminal(Some(cwd));
+                    match self.bus.os_input.as_mut().unwrap().spawn_terminal(
+                        shell,
+                        quit_cb,
+                        self.default_editor.clone(),
+                    ) {
+                        Ok((terminal_id, pid_primary, child_fd)) => {
+                            self.id_to_child_pid.insert(terminal_id, child_fd);
+                            new_pane_pids.push((terminal_id, None, Ok(pid_primary)));
+                        },
+                        Err(SpawnTerminalError::CommandNotFound(terminal_id)) => {
+                            new_pane_pids.push((
+                                terminal_id,
+                                None,
+                                Err(SpawnTerminalError::CommandNotFound(terminal_id)),
+                            ));
+                        },
+                        Err(e) => {
+                            log::error!("Failed to spawn terminal: {}", e);
+                        },
+                    }
+                },
                 None => {
                     match self.bus.os_input.as_mut().unwrap().spawn_terminal(
                         default_shell.clone(),
diff --git a/zellij-server/src/tab/unit/tab_integration_tests.rs b/zellij-server/src/tab/unit/tab_integration_tests.rs
index f1efe339d..42bfc3663 100644
--- a/zellij-server/src/tab/unit/tab_integration_tests.rs
+++ b/zellij-server/src/tab/unit/tab_integration_tests.rs
@@ -251,7 +251,7 @@ fn create_new_tab_with_layout(size: Size, default_mode: ModeInfo, layout: &str)
     let copy_options = CopyOptions::default();
     let terminal_emulator_color_codes = Rc::new(RefCell::new(HashMap::new()));
     let sixel_image_store = Rc::new(RefCell::new(SixelImageStore::default()));
-    let layout = Layout::from_str(layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_str(layout, "layout_file_name".into(), None).unwrap();
     let tab_layout = layout.new_tab();
     let mut tab = Tab::new(
         index,
diff --git a/zellij-server/src/unit/screen_tests.rs b/zellij-server/src/unit/screen_tests.rs
index 85e7b4a06..0ab13bf94 100644
--- a/zellij-server/src/unit/screen_tests.rs
+++ b/zellij-server/src/unit/screen_tests.rs
@@ -2207,6 +2207,7 @@ pub fn send_cli_new_tab_action_default_params() {
     let new_tab_action = CliAction::NewTab {
         name: None,
         layout: None,
+        cwd: None,
     };
     send_cli_action_to_server(
         &session_metadata,
@@ -2242,6 +2243,7 @@ pub fn send_cli_new_tab_action_with_name_and_layout() {
             "{}/src/unit/fixtures/layout-with-three-panes.kdl",
             env!("CARGO_MANIFEST_DIR")
         ))),
+        cwd: None,
     };
     send_cli_action_to_server(
         &session_metadata,
diff --git a/zellij-utils/src/cli.rs b/zellij-utils/src/cli.rs
index bef1afb33..ae0c2141c 100644
--- a/zellij-utils/src/cli.rs
+++ b/zellij-utils/src/cli.rs
@@ -253,5 +253,7 @@ pub enum CliAction {
         layout: Option<PathBuf>,
         #[clap(short, long, value_parser)]
         name: Option<String>,
+        #[clap(short, long, value_parser, requires("layout"))]
+        cwd: Option<PathBuf>,
     },
 }
diff --git a/zellij-utils/src/input/actions.rs b/zellij-utils/src/input/actions.rs
index de1350ddd..d337a75a9 100644
--- a/zellij-utils/src/input/actions.rs
+++ b/zellij-utils/src/input/actions.rs
@@ -344,12 +344,12 @@ impl Action {
                 Action::TabNameInput(name.as_bytes().to_vec()),
             ]),
             CliAction::UndoRenameTab => Ok(vec![Action::UndoRenameTab]),
-            CliAction::NewTab { name, layout } => {
+            CliAction::NewTab { name, layout, cwd } => {
                 if let Some(layout_path) = layout {
                     let (path_to_raw_layout, raw_layout) =
                         Layout::stringified_from_path_or_default(Some(&layout_path), None)
                             .map_err(|e| format!("Failed to load layout: {}", e))?;
-                    let layout = Layout::from_str(&raw_layout, path_to_raw_layout).map_err(|e| {
+                    let layout = Layout::from_str(&raw_layout, path_to_raw_layout, cwd).map_err(|e| {
                         let stringified_error = match e {
                             ConfigError::KdlError(kdl_error) => {
                                 let error = kdl_error.add_src(layout_path.as_path().as_os_str().to_string_lossy().to_string(), String::from(raw_layout));
diff --git a/zellij-utils/src/input/layout.rs b/zellij-utils/src/input/layout.rs
index f823ed401..8299c0bc2 100644
--- a/zellij-utils/src/input/layout.rs
+++ b/zellij-utils/src/input/layout.rs
@@ -62,6 +62,41 @@ pub enum Run {
     Plugin(RunPlugin),
     #[serde(rename = "command")]
     Command(RunCommand),
+    Cwd(PathBuf),
+}
+
+impl Run {
+    pub fn merge(base: &Option<Run>, other: &Option<Run>) -> Option<Run> {
+        // TODO: handle Plugin variants once there's a need
+        match (base, other) {
+            (Some(Run::Command(base_run_command)), Some(Run::Command(other_run_command))) => {
+                let mut merged = other_run_command.clone();
+                if merged.cwd.is_none() && base_run_command.cwd.is_some() {
+                    merged.cwd = base_run_command.cwd.clone();
+                }
+                if merged.args.is_empty() && !base_run_command.args.is_empty() {
+                    merged.args = base_run_command.args.clone();
+                }
+                Some(Run::Command(merged))
+            },
+            (Some(Run::Command(base_run_command)), Some(Run::Cwd(other_cwd))) => {
+                let mut merged = base_run_command.clone();
+                merged.cwd = Some(other_cwd.clone());
+                Some(Run::Command(merged))
+            },
+            (Some(Run::Cwd(base_cwd)), Some(Run::Command(other_command))) => {
+                let mut merged = other_command.clone();
+                if merged.cwd.is_none() {
+                    merged.cwd = Some(base_cwd.clone());
+                }
+                Some(Run::Command(merged))
+            },
+            (Some(_base), Some(other)) => Some(other.clone()),
+            (Some(base), _) => Some(base.clone()),
+            (None, Some(other)) => Some(other.clone()),
+            (None, None) => None,
+        }
+    }
 }
 
 #[derive(Debug, Serialize, Deserialize, Clone, PartialEq, Eq)]
@@ -252,12 +287,16 @@ impl Layout {
     ) -> Result<(Layout, Config), ConfigError> {
         let (path_to_raw_layout, raw_layout) =
             Layout::stringified_from_path_or_default(layout_path, layout_dir)?;
-        let layout = Layout::from_kdl(&raw_layout, path_to_raw_layout)?;
+        let layout = Layout::from_kdl(&raw_layout, path_to_raw_layout, None)?;
         let config = Config::from_kdl(&raw_layout, Some(config))?; // this merges the two config, with
         Ok((layout, config))
     }
-    pub fn from_str(raw: &str, path_to_raw_layout: String) -> Result<Layout, ConfigError> {
-        Layout::from_kdl(raw, path_to_raw_layout)
+    pub fn from_str(
+        raw: &str,
+        path_to_raw_layout: String,
+        cwd: Option<PathBuf>,
+    ) -> Result<Layout, ConfigError> {
+        Layout::from_kdl(raw, path_to_raw_layout, cwd)
     }
     pub fn stringified_from_dir(
         layout: &PathBuf,
diff --git a/zellij-utils/src/input/unit/layout_test.rs b/zellij-utils/src/input/unit/layout_test.rs
index ce077a42e..82a221e2e 100644
--- a/zellij-utils/src/input/unit/layout_test.rs
+++ b/zellij-utils/src/input/unit/layout_test.rs
@@ -4,7 +4,7 @@ use insta::assert_snapshot;
 #[test]
 fn empty_layout() {
     let kdl_layout = "layout";
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout::default()),
         ..Default::default()
@@ -19,7 +19,7 @@ fn layout_with_one_pane() {
             pane
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout::default()],
@@ -39,7 +39,7 @@ fn layout_with_multiple_panes() {
             pane
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![
@@ -68,7 +68,7 @@ fn layout_with_nested_panes() {
             }
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![
@@ -96,7 +96,7 @@ fn layout_with_tabs() {
             tab
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         tabs: vec![(None, PaneLayout::default())],
         template: Some(PaneLayout::default()),
@@ -120,7 +120,7 @@ fn layout_with_nested_differing_tabs() {
             }
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         tabs: vec![
             (
@@ -160,7 +160,7 @@ fn layout_with_panes_in_different_mixed_split_sizes() {
             pane size=2;
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![
@@ -195,7 +195,7 @@ fn layout_with_command_panes() {
             pane command="htop"
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -220,7 +220,7 @@ fn layout_with_command_panes_and_cwd() {
             pane command="htop" cwd="/path/to/my/cwd"
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -248,7 +248,7 @@ fn layout_with_command_panes_and_cwd_and_args() {
             }
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -280,7 +280,7 @@ fn layout_with_plugin_panes() {
             }
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![
@@ -313,7 +313,7 @@ fn layout_with_borderless_panes() {
             pane borderless=true
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -334,7 +334,7 @@ fn layout_with_focused_panes() {
             pane focus=true
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -355,7 +355,7 @@ fn layout_with_pane_names() {
             pane name="my awesome pane"
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         template: Some(PaneLayout {
             children: vec![PaneLayout {
@@ -377,7 +377,7 @@ fn layout_with_tab_names() {
             tab name="my cool tab name 2"
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         tabs: vec![
             (
@@ -410,7 +410,7 @@ fn layout_with_focused_tab() {
             tab
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         tabs: vec![
             (None, PaneLayout::default()),
@@ -444,7 +444,7 @@ fn layout_with_tab_templates() {
             one-above-one-below
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     let expected_layout = Layout {
         tabs: vec![
             (
@@ -518,7 +518,7 @@ fn layout_with_default_tab_template() {
             tab
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -545,7 +545,7 @@ fn layout_with_pane_templates() {
             left-and-right
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -566,7 +566,7 @@ fn layout_with_tab_and_pane_templates() {
             left-right-and-htop
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -587,7 +587,7 @@ fn layout_with_nested_pane_templates() {
             left-and-right
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -613,7 +613,7 @@ fn layout_with_nested_branched_pane_templates() {
             left-and-right
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -637,7 +637,7 @@ fn circular_dependency_pane_templates_error() {
             one
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into());
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None);
     assert!(layout.is_err(), "circular dependency detected");
 }
 
@@ -659,7 +659,7 @@ fn children_not_as_first_child_of_tab_template() {
             horizontal-with-vertical-top
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None).unwrap();
     assert_snapshot!(format!("{:#?}", layout));
 }
 
@@ -682,7 +682,7 @@ fn error_on_more_than_one_children_block_in_tab_template() {
             horizontal-with-vertical-top
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into());
+    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into(), None);
     assert!(
         layout.is_err(),
         "error provided for more than one children block"
@@ -707,7 +707,7 @@ fn children_not_as_first_child_of_pane_template() {
             horizontal-with-vertical-top
         }
     "#;
-    let layout = Layout::from_kdl(kdl_layout, "layout_file_name".into()).unwrap();
+    let layout = Layout::from_kdl(kdl_lay