Only allow unaliasing in current scope, add tests (#3936)

* unalias only removes aliases in the current scope

* Add a test and fix previous ones which did not function as expected

crates/nu-engine/src/evaluate/scope.rs

@@ -408,7 +408,7 @@ impl ParserScope for Scope {
  }
 
  fn remove_alias(&self, name: &str) {
- for frame in self.frames.lock().iter_mut().rev() {
+ if let Some(frame) = self.frames.lock().last_mut() {
  frame.aliases.remove(name);
  }
  }

tests/shell/pipeline/commands/internal.rs

@@ -1150,23 +1150,44 @@ fn unalias_shadowing() {
  let actual = nu!(
  cwd: ".", pipeline(
  r#"
- alias ll = ls -l
- let xyz = { ll -a }
- unalias ll
- do $xyz
+ def test-shadowing [] {
+ alias greet = echo hello;
+ let xyz = { greet };
+ unalias greet;
+ do $xyz
+ };
+ test-shadowing
  "#)
  );
+ assert_eq!(actual.out, "hello");
+}
 
- assert_eq!(actual.out, "");
+#[test]
+fn unalias_does_not_escape_scope() {
+ let actual = nu!(
+ cwd: ".", pipeline(
+ r#"
+ def test-alias [] {
+ alias greet = echo hello;
+ (unalias greet);
+ greet
+ };
+ test-alias
+ "#)
+ );
+ assert_eq!(actual.out, "hello");
 }
 
 #[test]
 fn unalias_hides_alias() {
  let actual = nu!(cwd: ".", pipeline(
- r#"alias ll = ls -l
- ll
- unalias ll
- ll
+ r#"
+ def test-alias [] {
+ alias ll = ls -l;
+ unalias ll;
+ ll
+ };
+ test-alias
  "#)
  );