feat: detect recursive closures properly

crates/emmylua_code_analysis/src/db_index/declaration/decl_tree.rs

@@ -151,13 +151,17 @@ impl LuaDeclarationTree {
     {
         match scope.get_kind() {
             LuaScopeKind::LocalOrAssignStat => {
-                let parent = scope.get_parent();
-                if let Some(parent) = parent {
-                    let parent_scope = match self.scopes.get(parent.id as usize) {
-                        Some(scope) => scope,
-                        None => return,
-                    };
-                    self.walk_up(parent_scope, scope.get_position(), level, f);
+                if level == 0 {
+                    let parent = scope.get_parent();
+                    if let Some(parent) = parent {
+                        let parent_scope = match self.scopes.get(parent.id as usize) {
+                            Some(scope) => scope,
+                            None => return,
+                        };
+                        self.walk_up(parent_scope, scope.get_position(), level, f);
+                    }
+                } else {
+                    self.base_walk_up(scope, start_pos, level, f);
                 }
             }
             LuaScopeKind::Repeat => {

crates/emmylua_code_analysis/src/diagnostic/test/incomplete_signature_doc_test.rs

@@ -24,15 +24,14 @@ mod tests {
         let mut ws = VirtualWorkspace::new();
         ws.enable_full_diagnostic();
 
-        // TODO: closures are not detected as functions in the semantic model
-        // assert!(!ws.check_code_for(
-        //     DiagnosticCode::MissingGlobalDoc,
-        //     r#"
-        //     local c = function(x, y)
-        //         return x + y
-        //     end
-        //     "#
-        // ));
+        assert!(!ws.check_code_for(
+            DiagnosticCode::IncompleteSignatureDoc,
+            r#"
+            local c = function(x, y)
+                return x + y
+            end
+            "#
+        ));
 
         assert!(!ws.check_code_for(
             DiagnosticCode::IncompleteSignatureDoc,

crates/emmylua_code_analysis/src/diagnostic/test/undefined_global_test.rs

@@ -20,4 +20,20 @@ mod test {
             "#
         ));
     }
+
+    #[test]
+    fn test_globals() {
+        let mut ws = VirtualWorkspace::new_with_init_std_lib();
+        assert!(ws.check_code_for(
+            DiagnosticCode::UndefinedGlobal,
+            r#"
+            local fact = function(n)
+                if n == 0 then
+                    return 1
+                end
+                return n * fact(n - 1)
+            end
+            "#
+        ));
+    }
 }

crates/emmylua_code_analysis/src/semantic/semantic_info/infer_expr_semantic_decl.rs

@@ -222,6 +222,26 @@ fn infer_closure_expr_semantic_decl(
                 level,
             )
         }
+        LuaStat::LocalStat(local_stat) => {
+            let local_name =
+                local_stat.get_local_name_by_value(LuaExpr::ClosureExpr(closure_expr))?;
+            let name_token = local_name.get_name_token()?;
+            infer_token_semantic_decl(db, cache, name_token.syntax().clone(), level)
+        }
+        LuaStat::AssignStat(assign_stat) => {
+            let (vars, exprs) = assign_stat.get_var_and_expr_list();
+            let idx = exprs.iter().position(|expr| {
+                matches!(expr, LuaExpr::ClosureExpr(ce) if ce.syntax() == closure_expr.syntax())
+            })?;
+            let var = vars.get(idx)?;
+            infer_expr_semantic_decl(
+                db,
+                cache,
+                var.clone().into(),
+                semantic_guard.next_level()?,
+                level,
+            )
+        }
         _ => None,
     }
 }