enable starting hx with a working directory (helix-editor#8223)

* added working path arg to cli and help menu

* improve working path cli arg handling

* enable hx to set the working path

* applied cargo formatting

* improved code from cargo clippy suggestion

* improved code from follow up review

* fix for -w <path> is set but args.files is empty

* improved formatting of --help output

helix-term/src/application.rs

@@ -156,6 +156,9 @@ impl Application {
         let editor_view = Box::new(ui::EditorView::new(Keymaps::new(keys)));
         compositor.push(editor_view);
 
+        if let Some(path) = args.working_directory {
+            helix_loader::set_current_working_dir(path)?
+        }
         if args.load_tutor {
             let path = helix_loader::runtime_file(Path::new("tutor"));
             editor.open(&path, Action::VerticalSplit)?;

helix-term/src/args.rs

@@ -17,6 +17,7 @@ pub struct Args {
     pub log_file: Option<PathBuf>,
     pub config_file: Option<PathBuf>,
     pub files: Vec<(PathBuf, Position)>,
+    pub working_directory: Option<PathBuf>,
 }
 
 impl Args {
@@ -59,6 +60,20 @@ impl Args {
                     Some(path) => args.log_file = Some(path.into()),
                     None => anyhow::bail!("--log must specify a path to write"),
                 },
+                "-w" | "--working-dir" => match argv.next().as_deref() {
+                    Some(path) => {
+                        args.working_directory = if Path::new(path).is_dir() {
+                            Some(PathBuf::from(path))
+                        } else {
+                            anyhow::bail!(
+                                "--working-dir specified does not exist or is not a directory"
+                            )
+                        }
+                    }
+                    None => {
+                        anyhow::bail!("--working-dir must specify an initial working directory")
+                    }
+                },
                 arg if arg.starts_with("--") => {
                     anyhow::bail!("unexpected double dash argument: {}", arg)
                 }

helix-term/src/main.rs

@@ -66,6 +66,7 @@ FLAGS:
     -V, --version                  Prints version information
     --vsplit                       Splits all given files vertically into different windows
     --hsplit                       Splits all given files horizontally into different windows
+    -w, --working-dir <path>       Specify an initial working directory
 ",
         env!("CARGO_PKG_NAME"),
         VERSION_AND_GIT_HASH,