From 93deb1f6ae891c2fad144c3807515ad3b13004d6 Mon Sep 17 00:00:00 2001
From: Nikita Revenco <154856872+NikitaRevenco@users.noreply.github.com>
Date: Thu, 5 Dec 2024 23:40:37 +0000
Subject: [PATCH] feat: `:cd -` changes to the previous working directory
 (#12194)

Co-authored-by: Michael Davis <mcarsondavis@gmail.com>
---
 helix-stdx/src/env.rs            | 7 ++++---
 helix-term/src/commands/typed.rs | 8 +++++++-
 helix-view/src/editor.rs         | 2 ++
 3 files changed, 13 insertions(+), 4 deletions(-)

diff --git a/helix-stdx/src/env.rs b/helix-stdx/src/env.rs
index d29a98fde..6e14c7a87 100644
--- a/helix-stdx/src/env.rs
+++ b/helix-stdx/src/env.rs
@@ -7,6 +7,7 @@
 
 use once_cell::sync::Lazy;
 
+// We keep the CWD as a static so that we can access it in places where we don't have access to the Editor
 static CWD: RwLock<Option<PathBuf>> = RwLock::new(None);
 
 // Get the current working directory.
@@ -36,12 +37,12 @@ pub fn current_working_dir() -> PathBuf {
     cwd
 }
 
-pub fn set_current_working_dir(path: impl AsRef<Path>) -> std::io::Result<()> {
+pub fn set_current_working_dir(path: impl AsRef<Path>) -> std::io::Result<Option<PathBuf>> {
     let path = crate::path::canonicalize(path);
     std::env::set_current_dir(&path)?;
     let mut cwd = CWD.write().unwrap();
-    *cwd = Some(path);
-    Ok(())
+
+    Ok(cwd.replace(path))
 }
 
 pub fn env_var_is_set(env_var_name: &str) -> bool {
diff --git a/helix-term/src/commands/typed.rs b/helix-term/src/commands/typed.rs
index e6ec8b571..25288ad29 100644
--- a/helix-term/src/commands/typed.rs
+++ b/helix-term/src/commands/typed.rs
@@ -1091,6 +1091,11 @@ fn change_current_directory(
     }
 
     let dir = match args.first() {
+        Some(Cow::Borrowed("-")) => cx
+            .editor
+            .last_cwd
+            .clone()
+            .ok_or(anyhow!("No previous working directory"))?,
         Some(input_path) => {
             helix_stdx::path::expand_tilde(Path::new(input_path.as_ref()).to_owned())
                 .deref()
@@ -1099,12 +1104,13 @@ fn change_current_directory(
         None => home_dir()?.as_path().to_owned(),
     };
 
-    helix_stdx::env::set_current_working_dir(dir)?;
+    cx.editor.last_cwd = helix_stdx::env::set_current_working_dir(dir)?;
 
     cx.editor.set_status(format!(
         "Current working directory is now {}",
         helix_stdx::env::current_working_dir().display()
     ));
+
     Ok(())
 }
 
diff --git a/helix-view/src/editor.rs b/helix-view/src/editor.rs
index 174190e5d..aa9a11533 100644
--- a/helix-view/src/editor.rs
+++ b/helix-view/src/editor.rs
@@ -1073,6 +1073,7 @@ pub struct Editor {
     redraw_timer: Pin<Box<Sleep>>,
     last_motion: Option<Motion>,
     pub last_completion: Option<CompleteAction>,
+    pub last_cwd: Option<PathBuf>,
 
     pub exit_code: i32,
 
@@ -1206,6 +1207,7 @@ pub fn new(
             redraw_timer: Box::pin(sleep(Duration::MAX)),
             last_motion: None,
             last_completion: None,
+            last_cwd: None,
             config,
             auto_pairs,
             exit_code: 0,