fix(completion): missing local variables

Author: blindFS

crates/nu-cli/tests/completions/mod.rs

@@ -1980,6 +1980,20 @@ fn variables_completions() {
     match_suggestions(&expected, &suggestions);
 }
 
+#[test]
+fn local_variable_completion() {
+    let (_, _, engine, stack) = new_engine();
+    let mut completer = NuCompleter::new(Arc::new(engine), Arc::new(stack));
+
+    let completion_str =
+        "def test [foo?: string, --fooo: bool, ...foooo] { let fooooo = true; $foo";
+    let suggestions = completer.complete(completion_str, completion_str.len());
+
+    // https://github.com/nushell/nushell/issues/15291
+    let expected: Vec<_> = vec!["$foo", "$fooo", "$foooo", "$fooooo"];
+    match_suggestions(&expected, &suggestions);
+}
+
 #[test]
 fn record_cell_path_completions() {
     let (_, _, mut engine, mut stack) = new_engine();

crates/nu-lsp/src/completion.rs

@@ -23,7 +23,12 @@ impl LanguageServer {
         // fallback to default completer where
         // the text is truncated to `location` and
         // an extra placeholder token is inserted for correct parsing
+        let is_variable = file_text
+            .get(..location)
+            .and_then(|s| s.rsplit(' ').next())
+            .is_some_and(|last_word| last_word.starts_with('$'));
         let need_fallback = location == 0
+            || is_variable
             || file_text
                 .get(location - 1..location)
                 .and_then(|s| s.chars().next())

crates/nu-parser/src/parse_keywords.rs

@@ -595,7 +595,12 @@ fn parse_def_inner(
             let mut new_errors = working_set.parse_errors[starting_error_count..].to_vec();
             working_set.parse_errors.truncate(starting_error_count);
 
-            working_set.exit_scope();
+            if new_errors
+                .iter()
+                .all(|e| !matches!(e, ParseError::Unclosed(token, _) if token == "}"))
+            {
+                working_set.exit_scope();
+            }
 
             let call_span = Span::concat(spans);
             let decl = working_set.get_decl(decl_id);

crates/nu-parser/src/parser.rs

@@ -5090,6 +5090,7 @@ pub fn parse_closure_expression(
 
     let mut start = span.start;
     let mut end = span.end;
+    let mut is_unclosed = false;
 
     if bytes.starts_with(b"{") {
         start += 1;
@@ -5101,6 +5102,7 @@ pub fn parse_closure_expression(
         end -= 1;
     } else {
         working_set.error(ParseError::Unclosed("}".into(), Span::new(end, end)));
+        is_unclosed = true;
     }
 
     let inner_span = Span::new(start, end);
@@ -5197,7 +5199,9 @@ pub fn parse_closure_expression(
 
     output.span = Some(span);
 
-    working_set.exit_scope();
+    if !is_unclosed {
+        working_set.exit_scope();
+    }
 
     let block_id = working_set.add_block(Arc::new(output));