From bdb72acbc11d6a2e50f38fa15ca04ec74af44200 Mon Sep 17 00:00:00 2001
From: ShenzhenGopher <lizh629@mail2.sysu.edu.cn>
Date: Thu, 11 Jun 2026 09:14:47 +0000
Subject: [PATCH] [FIX] fix false undefined-field for table<K,V> when value
 type is generic and key is not string/integer

When a table<K,V> field has a generic value type (e.g. Box<unknown>?)
and the key type K is not string or integer (e.g. thread, boolean),
indexing the table with a correctly-typed key falsely reports
undefined-field.

Root cause: get_key_types() only recognized string, integer and a few
other types, silently dropping thread/boolean/number/userdata. The
subsequent ExprType member matching also only handled string and integer.

Fix:
- Add thread/boolean/number/userdata to get_key_types()
- Add fallback equality check in ExprType matching branch
- Add test cases for thread and boolean key types
---
 .../src/diagnostic/checker/check_field.rs     |  5 +++
 .../diagnostic/test/undefined_field_test.rs   | 44 +++++++++++++++++++
 2 files changed, 49 insertions(+)

diff --git a/crates/emmylua_code_analysis/src/diagnostic/checker/check_field.rs b/crates/emmylua_code_analysis/src/diagnostic/checker/check_field.rs
index 47d22a516..df25bc6ad 100644
--- a/crates/emmylua_code_analysis/src/diagnostic/checker/check_field.rs
+++ b/crates/emmylua_code_analysis/src/diagnostic/checker/check_field.rs
@@ -274,6 +274,8 @@ pub(super) fn is_valid_member(
                             }
                         } else if typ.is_integer() && key_types.iter().any(|typ| typ.is_integer()) {
                             return Some(());
+                        } else if key_types.iter().any(|kt| kt == typ) {
+                            return Some(());
                         }
                     }
                     LuaMemberKey::Name(_) => {
@@ -378,6 +380,9 @@ fn get_key_types(db: &DbIndex, typ: &LuaType) -> HashSet<LuaType> {
             LuaType::DocStringConst(_) | LuaType::DocIntegerConst(_) => {
                 type_set.insert(current_type);
             }
+            LuaType::Boolean | LuaType::Thread | LuaType::Number | LuaType::Userdata => {
+                type_set.insert(current_type);
+            }
             LuaType::Call(alias_call) => {
                 if let Some(key_types) = get_keyof_keys(db, alias_call) {
                     for t in key_types {
diff --git a/crates/emmylua_code_analysis/src/diagnostic/test/undefined_field_test.rs b/crates/emmylua_code_analysis/src/diagnostic/test/undefined_field_test.rs
index cfefece06..b380f6d2d 100644
--- a/crates/emmylua_code_analysis/src/diagnostic/test/undefined_field_test.rs
+++ b/crates/emmylua_code_analysis/src/diagnostic/test/undefined_field_test.rs
@@ -900,4 +900,48 @@ mod test {
         assert_eq!(ws.expr_ty("alias_result"), ws.ty("string?"));
         assert_eq!(ws.expr_ty("numeric_result"), ws.ty("string?"));
     }
+
+    #[test]
+    fn test_table_generic_value_with_thread_key() {
+        let mut ws = VirtualWorkspace::new();
+        assert!(ws.has_no_diagnostic(
+            DiagnosticCode::UndefinedField,
+            r#"
+                ---@class Box<T>
+                ---@field value T
+
+                ---@class Container
+                ---@field items table<thread, Box<unknown>?>
+                local Container = {}
+
+                ---@param co thread
+                function Container:get(co)
+                    local item = self.items[co]
+                    return item
+                end
+            "#
+        ));
+    }
+
+    #[test]
+    fn test_table_generic_value_with_boolean_key() {
+        let mut ws = VirtualWorkspace::new();
+        assert!(ws.has_no_diagnostic(
+            DiagnosticCode::UndefinedField,
+            r#"
+                ---@class Box<T>
+                ---@field value T
+
+                ---@class Container
+                ---@field items table<boolean, Box<unknown>?>
+                local Container = {}
+
+                ---@param key boolean
+                function Container:get(key)
+                    local item = self.items[key]
+                    return item
+                end
+            "#
+        ));
+    }
 }