diff --git a/flake.nix b/flake.nix
index 58b1100..7acd0f9 100644
--- a/flake.nix
+++ b/flake.nix
@@ -22,9 +22,12 @@
         lockFile = ./Cargo.lock;
       };
 
-      doCheck = false;
       passthru.shellPath = "/bin/shed";
 
+      checkPhase = ''
+        cargo test -- --test-threads=1
+      '';
+
       meta = with pkgs.lib; {
         description = "A Linux shell written in Rust";
         homepage = "https://github.com/km-clay/shed";
diff --git a/src/builtin/dirstack.rs b/src/builtin/dirstack.rs
index d4ea28f..9f498e3 100644
--- a/src/builtin/dirstack.rs
+++ b/src/builtin/dirstack.rs
@@ -429,7 +429,7 @@ pub fn dirs(node: Node) -> ShResult<()> {
 #[cfg(test)]
 pub mod tests {
 	use std::{env, path::PathBuf};
-	use crate::{parse::execute::exec_input, state::{self, read_meta}, testutil::TestGuard};
+	use crate::{state::{self, read_meta}, testutil::{TestGuard, test_input}};
 	use pretty_assertions::{assert_ne,assert_eq};
 use tempfile::TempDir;
 
@@ -438,7 +438,7 @@ use tempfile::TempDir;
 		let g = TestGuard::new();
 		let current_dir = env::current_dir().unwrap();
 
-		exec_input("pushd /tmp".into(), None, true, None).unwrap();
+		test_input("pushd /tmp").unwrap();
 
 		let new_dir = env::current_dir().unwrap();
 
@@ -461,7 +461,7 @@ use tempfile::TempDir;
 		let tempdir = TempDir::new().unwrap();
 		let tempdir_raw = tempdir.path().to_path_buf().to_string_lossy().to_string();
 
-		exec_input(format!("pushd {tempdir_raw}"), None, true, None).unwrap();
+		test_input(format!("pushd {tempdir_raw}")).unwrap();
 
 		let dir_stack = read_meta(|m| m.dirs().clone());
 		assert_eq!(dir_stack.len(), 1);
@@ -470,7 +470,7 @@ use tempfile::TempDir;
 		assert_eq!(env::current_dir().unwrap(), tempdir.path());
 		g.read_output(); // consume output of pushd
 
-		exec_input("popd".into(), None, true, None).unwrap();
+		test_input("popd").unwrap();
 
 		assert_eq!(env::current_dir().unwrap(), current_dir);
 		let out = g.read_output();
@@ -482,7 +482,7 @@ use tempfile::TempDir;
 	fn test_popd_empty_stack() {
 		let _g = TestGuard::new();
 
-		exec_input("popd".into(), None, false, None).unwrap_err();
+		test_input("popd").unwrap_err();
 		assert_ne!(state::get_status(), 0);
 	}
 
@@ -495,8 +495,8 @@ use tempfile::TempDir;
 		let path1 = tmp1.path().to_path_buf();
 		let path2 = tmp2.path().to_path_buf();
 
-		exec_input(format!("pushd {}", path1.display()), None, false, None).unwrap();
-		exec_input(format!("pushd {}", path2.display()), None, false, None).unwrap();
+		test_input(format!("pushd {}", path1.display())).unwrap();
+		test_input(format!("pushd {}", path2.display())).unwrap();
 		g.read_output();
 
 		assert_eq!(env::current_dir().unwrap(), path2);
@@ -505,10 +505,10 @@ use tempfile::TempDir;
 		assert_eq!(stack[0], path1);
 		assert_eq!(stack[1], original);
 
-		exec_input("popd".into(), None, false, None).unwrap();
+		test_input("popd").unwrap();
 		assert_eq!(env::current_dir().unwrap(), path1);
 
-		exec_input("popd".into(), None, false, None).unwrap();
+		test_input("popd").unwrap();
 		assert_eq!(env::current_dir().unwrap(), original);
 
 		let stack = read_meta(|m| m.dirs().clone());
@@ -526,13 +526,13 @@ use tempfile::TempDir;
 
 		// Build stack: cwd=original, then pushd path1, pushd path2
 		// Stack after: cwd=path2, [path1, original]
-		exec_input(format!("pushd {}", path1.display()), None, false, None).unwrap();
-		exec_input(format!("pushd {}", path2.display()), None, false, None).unwrap();
+		test_input(format!("pushd {}", path1.display())).unwrap();
+		test_input(format!("pushd {}", path2.display())).unwrap();
 		g.read_output();
 
 		// pushd +1 rotates: [path2, path1, original] -> rotate_left(1) -> [path1, original, path2]
 		// pop front -> cwd=path1, stack=[original, path2]
-		exec_input("pushd +1".into(), None, false, None).unwrap();
+		test_input("pushd +1").unwrap();
 		assert_eq!(env::current_dir().unwrap(), path1);
 
 		let stack = read_meta(|m| m.dirs().clone());
@@ -548,7 +548,7 @@ use tempfile::TempDir;
 		let tmp = TempDir::new().unwrap();
 		let path = tmp.path().to_path_buf();
 
-		exec_input(format!("pushd -n {}", path.display()), None, false, None).unwrap();
+		test_input(format!("pushd -n {}", path.display())).unwrap();
 
 		// -n means don't cd, but the dir should still be on the stack
 		assert_eq!(env::current_dir().unwrap(), original);
@@ -559,10 +559,10 @@ use tempfile::TempDir;
 		let _g = TestGuard::new();
 		let tmp = TempDir::new().unwrap();
 
-		exec_input(format!("pushd {}", tmp.path().display()), None, false, None).unwrap();
+		test_input(format!("pushd {}", tmp.path().display())).unwrap();
 		assert_eq!(read_meta(|m| m.dirs().len()), 1);
 
-		exec_input("dirs -c".into(), None, false, None).unwrap();
+		test_input("dirs -c").unwrap();
 		assert_eq!(read_meta(|m| m.dirs().len()), 0);
 	}
 
@@ -573,10 +573,10 @@ use tempfile::TempDir;
 		let tmp = TempDir::new().unwrap();
 		let path = tmp.path().to_path_buf();
 
-		exec_input(format!("pushd {}", path.display()), None, false, None).unwrap();
+		test_input(format!("pushd {}", path.display())).unwrap();
 		g.read_output();
 
-		exec_input("dirs -p".into(), None, false, None).unwrap();
+		test_input("dirs -p").unwrap();
 		let out = g.read_output();
 		let lines: Vec<&str> = out.split('\n').filter(|l| !l.is_empty()).collect();
 		assert_eq!(lines.len(), 2);
@@ -594,11 +594,11 @@ use tempfile::TempDir;
 		let path2 = tmp2.path().to_path_buf();
 
 		// Stack: cwd=path2, [path1, original]
-		exec_input(format!("pushd {}", path1.display()), None, false, None).unwrap();
-		exec_input(format!("pushd {}", path2.display()), None, false, None).unwrap();
+		test_input(format!("pushd {}", path1.display())).unwrap();
+		test_input(format!("pushd {}", path2.display())).unwrap();
 
 		// popd +1 removes index (1-1)=0 from stored dirs, i.e. path1
-		exec_input("popd +1".into(), None, false, None).unwrap();
+		test_input("popd +1").unwrap();
 		assert_eq!(env::current_dir().unwrap(), path2); // no cd
 
 		let stack = read_meta(|m| m.dirs().clone());
@@ -610,7 +610,7 @@ use tempfile::TempDir;
 	fn test_pushd_nonexistent_dir() {
 		let _g = TestGuard::new();
 
-		let result = exec_input("pushd /nonexistent_dir_12345".into(), None, false, None);
+		let result = test_input("pushd /nonexistent_dir_12345");
 		assert!(result.is_err());
 	}
 }
diff --git a/src/parse/execute.rs b/src/parse/execute.rs
index 5b53221..6c40111 100644
--- a/src/parse/execute.rs
+++ b/src/parse/execute.rs
@@ -411,7 +411,8 @@ impl Dispatcher {
 
     blame.rename(func_name.clone());
 
-    let argv = prepare_argv(argv).try_blame(blame.clone())?;
+    let mut argv = prepare_argv(argv).try_blame(blame.clone())?;
+    argv.insert(0, (func_name.clone(), blame.clone()));
     let result = if let Some(ref mut func_body) = read_logic(|l| l.get_func(&func_name)) {
       let _guard = scope_guard(Some(argv));
       func_body.body_mut().propagate_context(func_ctx);
diff --git a/src/readline/complete.rs b/src/readline/complete.rs
index d923db2..f6475ea 100644
--- a/src/readline/complete.rs
+++ b/src/readline/complete.rs
@@ -226,7 +226,7 @@ fn complete_filename(start: &str) -> Vec<String> {
       let mut full_path = dir.join(&file_name);
 
       // Add trailing slash for directories
-      if entry.file_type().map(|ft| ft.is_dir()).unwrap_or(false) {
+      if entry.metadata().map(|m| m.is_dir()).unwrap_or(false) {
         full_path.push(""); // adds trailing /
       }
 
diff --git a/src/readline/mod.rs b/src/readline/mod.rs
index 111e94b..ef8e9ca 100644
--- a/src/readline/mod.rs
+++ b/src/readline/mod.rs
@@ -488,6 +488,16 @@ impl ShedVi {
             self.needs_redraw = true;
             self.completer.reset();
 
+            write_vars(|v| {
+              v.set_var(
+                "SHED_VI_MODE",
+                VarKind::Str(self.mode.report_mode().to_string()),
+                VarFlags::NONE,
+              )
+            })
+            .ok();
+            self.prompt.refresh();
+
             with_vars([("_COMP_CANDIDATE".into(), candidate.clone())], || {
               post_cmds.exec_with(&candidate);
             });
@@ -642,6 +652,13 @@ impl ShedVi {
             .update_pending_cmd((self.editor.as_str(), self.editor.cursor.get()));
           let hint = self.history.get_hint();
           self.editor.set_hint(hint);
+					write_vars(|v| {
+						v.set_var(
+							"SHED_VI_MODE",
+							VarKind::Str(self.mode.report_mode().to_string()),
+							VarFlags::NONE,
+						)
+					}).ok();
 
           // If we are here, we hit a case where pressing tab returned a single candidate
           // So we can just go ahead and reset the completer after this
diff --git a/src/state.rs b/src/state.rs
index a2d0358..4f95adb 100644
--- a/src/state.rs
+++ b/src/state.rs
@@ -195,7 +195,7 @@ impl ScopeStack {
     new
   }
   pub fn descend(&mut self, argv: Option<Vec<String>>) {
-    let mut new_vars = VarTab::new();
+    let mut new_vars = VarTab::bare();
     if let Some(argv) = argv {
       for arg in argv {
         new_vars.bpush_arg(arg);
@@ -494,6 +494,13 @@ impl ScopeStack {
     {
       return val.clone();
     }
+    // Positional params are scope-local; only check the current scope
+    if matches!(param, ShellParam::Pos(_) | ShellParam::AllArgs | ShellParam::AllArgsStr | ShellParam::ArgCount) {
+      if let Some(scope) = self.scopes.last() {
+        return scope.get_param(param);
+      }
+      return "".into();
+    }
     for scope in self.scopes.iter().rev() {
       let val = scope.get_param(param);
       if !val.is_empty() {
@@ -996,6 +1003,14 @@ pub struct VarTab {
 }
 
 impl VarTab {
+  pub fn bare() -> Self {
+    Self {
+      vars: HashMap::new(),
+      params: HashMap::new(),
+      sh_argv: VecDeque::new(),
+      maps: HashMap::new(),
+    }
+  }
   pub fn new() -> Self {
     let vars = HashMap::new();
     let params = Self::init_params();
diff --git a/src/testutil.rs b/src/testutil.rs
index 871e636..3868342 100644
--- a/src/testutil.rs
+++ b/src/testutil.rs
@@ -32,7 +32,7 @@ pub fn has_cmd(cmd: &str) -> bool {
 }
 
 pub fn test_input(input: impl Into<String>) -> ShResult<()> {
-	exec_input(input.into(), None, true, None)
+	exec_input(input.into(), None, false, None)
 }
 
 pub struct TestGuard {