Some code refactor for shells related commands (#6226)

crates/nu-command/src/shells/enter.rs

@@ -1,3 +1,4 @@
+use super::{get_current_shell, get_shells};
 use nu_engine::{current_dir, CallExt};
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -62,21 +63,8 @@ impl Command for Enter {
             span: call.head,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let mut shells = get_shells(engine_state, stack, cwd);
-        let mut shells = if let Some(v) = shells {
+        let mut current_shell = get_current_shell(engine_state, stack);
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
-
-        let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
-        let mut current_shell = if let Some(v) = current_shell {
-            v.as_integer().unwrap_or_default() as usize
-        } else {
-            0
-        };
 
         if current_shell + 1 > shells.len() {
             shells.push(new_path.clone());

crates/nu-command/src/shells/exit.rs

@@ -1,3 +1,4 @@
+use super::{get_current_shell, get_shells};
 use nu_engine::{current_dir, CallExt};
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -57,21 +58,8 @@ impl Command for Exit {
             span: call.head,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let mut shells = get_shells(engine_state, stack, cwd);
-        let mut shells = if let Some(v) = shells {
+        let mut current_shell = get_current_shell(engine_state, stack);
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
-
-        let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
-        let mut current_shell = if let Some(v) = current_shell {
-            v.as_integer().unwrap_or_default() as usize
-        } else {
-            0
-        };
 
         shells.remove(current_shell);
 

crates/nu-command/src/shells/g.rs

@@ -1,3 +1,4 @@
+use super::get_shells;
 use nu_engine::{current_dir, CallExt};
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -43,14 +44,7 @@ impl Command for GotoShell {
             span: call.head,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let shells = get_shells(engine_state, stack, cwd);
-        let shells = if let Some(v) = shells {
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
 
         let new_path = if let Some(v) = shells.get(new_shell.item as usize) {
             v.clone()

crates/nu-command/src/shells/mod.rs

@@ -9,5 +9,28 @@ pub use enter::Enter;
 pub use exit::Exit;
 pub use g::GotoShell;
 pub use n::NextShell;
+use nu_protocol::engine::{EngineState, Stack};
+use nu_protocol::Value;
 pub use p::PrevShell;
 pub use shells_::Shells;
+
+fn get_shells(engine_state: &EngineState, stack: &mut Stack, cwd: Value) -> Vec<Value> {
+    let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+    let shells = if let Some(v) = shells {
+        v.as_list()
+            .map(|x| x.to_vec())
+            .unwrap_or_else(|_| vec![cwd])
+    } else {
+        vec![cwd]
+    };
+    shells
+}
+
+fn get_current_shell(engine_state: &EngineState, stack: &mut Stack) -> usize {
+    let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
+    if let Some(v) = current_shell {
+        v.as_integer().unwrap_or_default() as usize
+    } else {
+        0
+    }
+}

crates/nu-command/src/shells/n.rs

@@ -1,3 +1,4 @@
+use super::{get_current_shell, get_shells};
 use nu_engine::current_dir;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -33,21 +34,8 @@ impl Command for NextShell {
             span: call.head,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let shells = get_shells(engine_state, stack, cwd);
-        let shells = if let Some(v) = shells {
+        let mut current_shell = get_current_shell(engine_state, stack);
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
-
-        let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
-        let mut current_shell = if let Some(v) = current_shell {
-            v.as_integer().unwrap_or_default() as usize
-        } else {
-            0
-        };
 
         current_shell += 1;
 

crates/nu-command/src/shells/p.rs

@@ -1,3 +1,4 @@
+use super::{get_current_shell, get_shells};
 use nu_engine::current_dir;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -33,21 +34,8 @@ impl Command for PrevShell {
             span: call.head,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let shells = get_shells(engine_state, stack, cwd);
-        let shells = if let Some(v) = shells {
+        let mut current_shell = get_current_shell(engine_state, stack);
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
-
-        let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
-        let mut current_shell = if let Some(v) = current_shell {
-            v.as_integer().unwrap_or_default() as usize
-        } else {
-            0
-        };
 
         if current_shell == 0 {
             current_shell = shells.len() - 1;

crates/nu-command/src/shells/shells_.rs

@@ -1,3 +1,4 @@
+use super::{get_current_shell, get_shells};
 use nu_engine::current_dir;
 use nu_protocol::ast::Call;
 use nu_protocol::engine::{Command, EngineState, Stack};
@@ -36,21 +37,8 @@ impl Command for Shells {
             span,
         };
 
-        let shells = stack.get_env_var(engine_state, "NUSHELL_SHELLS");
+        let shells = get_shells(engine_state, stack, cwd);
-        let shells = if let Some(v) = shells {
+        let current_shell = get_current_shell(engine_state, stack);
-            v.as_list()
-                .map(|x| x.to_vec())
-                .unwrap_or_else(|_| vec![cwd])
-        } else {
-            vec![cwd]
-        };
-
-        let current_shell = stack.get_env_var(engine_state, "NUSHELL_CURRENT_SHELL");
-        let current_shell = if let Some(v) = current_shell {
-            v.as_integer().unwrap_or_default() as usize
-        } else {
-            0
-        };
 
         let output = shells
             .into_iter()