helix-term: cd to the parent of the current document when provided no…

… arguments

helix-term/src/commands/typed.rs

@@ -911,12 +911,21 @@ fn change_current_directory(
         return Ok(());
     }
 
-    let dir = helix_core::path::expand_tilde(
-        args.first()
-            .context("target directory not provided")?
-            .as_ref()
-            .as_ref(),
-    );
+    let dir = match args.first() {
+        Some(dir) => helix_core::path::expand_tilde(dir.as_ref().as_ref()),
+        None => {
+            let (_, doc) = current_ref!(cx.editor);
+            match doc.path() {
+                Some(path) => path
+                    .parent()
+                    .map(ToOwned::to_owned)
+                    .context("Couldn't get parent of current document")?,
+                None => {
+                    bail!("Current document has no path");
+                }
+            }
+        }
+    };
 
     if let Err(e) = std::env::set_current_dir(dir) {
         bail!("Couldn't change the current working directory: {}", e);