From d2d307e66400d5ca5337732b659ec49b8af911e0 Mon Sep 17 00:00:00 2001
From: sogav21 <223452947+sogav21@users.noreply.github.com>
Date: Wed, 11 Nov 2026 09:42:54 +0200
Subject: [PATCH] fix: preserve inherited generic table fields

---
 changelog.md                                  |   1 +
 script/vm/compiler.lua                        |  26 +++
 test/definition/luadoc.lua                    |   9 +
 test/hover/init.lua                           |  10 ++
 .../type_inference/inherited_table_fields.lua | 161 ++++++++++++++++++
 test/type_inference/init.lua                  |   1 +
 6 files changed, 208 insertions(+)
 create mode 100644 test/type_inference/inherited_table_fields.lua

diff --git a/changelog.md b/changelog.md
index daefdb5ae..24bfd30b9 100644
--- a/changelog.md
+++ b/changelog.md
@@ -2,6 +2,7 @@
 
 ## Unreleased
 <!-- Add all new changes here. They will be moved under a version at release -->
+* `FIX` Preserve inherited fields and their generic types when a class extends an anonymous table type [#3443](https://github.com/LuaLS/lua-language-server/issues/3443)
 
 ## 3.19.2
 `2026-10-13`
diff --git a/script/vm/compiler.lua b/script/vm/compiler.lua
index 20ab3ac41..4ef269a1a 100644
--- a/script/vm/compiler.lua
+++ b/script/vm/compiler.lua
@@ -774,6 +774,32 @@ function vm.getClassFields(suri, object, key, pushResult)
                                 end
                             end)
                         end
+                        -- Compiling a named base also resolves its anonymous
+                        -- table bases, including the supplied generic arguments.
+                        if extend.type == 'doc.extends.name'
+                        or extend.type == 'doc.type.sign' then
+                            local hasTable = false
+                            for node in vm.compileNode(extend):eachObject() do
+                                if node.type == 'doc.type.table' then
+                                    if not hasTable then
+                                        copyToSearched()
+                                        hasTable = true
+                                    end
+                                    searchFieldSwitch(node.type, suri, node, key, function (field, isMark)
+                                        local fieldKey = guide.getKeyName(field)
+                                        if not fieldKey or not searchedFields[fieldKey] then
+                                            if fieldKey then
+                                                hasFounded[fieldKey] = true
+                                            end
+                                            pushResult(field, isMark)
+                                        end
+                                    end)
+                                end
+                            end
+                            if hasTable then
+                                copyToSearched()
+                            end
+                        end
                     end
                 end
             end
diff --git a/test/definition/luadoc.lua b/test/definition/luadoc.lua
index e7c2be22d..d88d9a00b 100644
--- a/test/definition/luadoc.lua
+++ b/test/definition/luadoc.lua
@@ -764,6 +764,15 @@ local t
 print(t.<?x?>)
 ]]
 
+-- Issue #3443: inherited anonymous table fields retain their definition.
+TEST [[
+---@class GenericSuper<T>: { <!value!>: T }
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+print(t.<?value?>)
+]]
+
 TEST [[
 ---@alias TT<V> { <!x!>: V }
 
diff --git a/test/hover/init.lua b/test/hover/init.lua
index dbe245ad4..04b22c9c5 100644
--- a/test/hover/init.lua
+++ b/test/hover/init.lua
@@ -32,6 +32,16 @@ end
 
 config.set(nil, 'Lua.hover.previewFields', 50)
 
+-- Issue #3443: preserve fields from a generic anonymous table base.
+TEST [[
+---@class GenericSuper<T>: { value: T }
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+print(t.<?value?>)
+]]
+[[(field) Specific.value: string]]
+
 TEST [[
 local function <?x?>(a, b)
 end
diff --git a/test/type_inference/inherited_table_fields.lua b/test/type_inference/inherited_table_fields.lua
new file mode 100644
index 000000000..6f8f63f6f
--- /dev/null
+++ b/test/type_inference/inherited_table_fields.lua
@@ -0,0 +1,161 @@
+-- Issue #3443: fields declared in an anonymous table base survive inheritance.
+TEST 'boolean|string' [[
+---@alias UnionBase<T> { value: T }|{ value: boolean }
+---@class Specific: UnionBase<string>
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'boolean|string' [[
+---@alias UnionBase { value: string }|{ value: boolean }
+---@type UnionBase
+local t
+local <?value?> = t.value
+]]
+
+TEST 'boolean|string' [[
+---@alias UnionBase { value: string }|{ value: boolean }
+---@class Specific: UnionBase
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'unknown' [[
+---@class Recursive: Recursive
+---@type Recursive
+local t
+local <?value?> = t.value
+]]
+
+TEST 'boolean' [[
+---@class GenericSuper<T>: { value: T }
+---@field value boolean
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class First
+---@field value string
+---@class Second
+---@field value boolean
+---@class Specific: First, Second
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class First: { value: string }
+---@class Second: { value: boolean }
+---@class Specific: First, Second
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class First: Second
+---@class Second: First, { value: string }
+---@type First
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class GenericSuper<T>: { value: T }
+---@class Specific: GenericSuper<string>
+---@class Grandchild: Specific
+---@type Grandchild
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class GenericSuper<T>: { value: T }
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'boolean' [[
+---@class Container<K, V>: { key: K, value: V }
+---@class Specific: Container<string, boolean>
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class Container<K, V>: { key: K, value: V }
+---@class Specific: Container<string, boolean>
+---@type Specific
+local t
+local <?key?> = t.key
+]]
+
+TEST 'string[]' [[
+---@class GenericSuper<T>: { values: T[] }
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+local <?values?> = t.values
+]]
+
+TEST 'string?' [[
+---@class Base: { value?: string }
+---@class Specific: Base
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class GenericSuper<T>: { [integer]: T }
+---@class Specific: GenericSuper<string>
+---@type Specific
+local t
+local <?value?> = t[1]
+]]
+
+TEST 'integer' [[
+---@class GenericSuper<T>: { value: T }
+---@class StringChild: GenericSuper<string>
+---@class IntegerChild: GenericSuper<integer>
+---@type StringChild
+local a
+local value = a.value
+---@type IntegerChild
+local b
+local <?value?> = b.value
+]]
+
+TEST 'string' [[
+---@class Base: { value: string }
+---@class Child: Base
+---@class Grandchild: Child
+---@type Grandchild
+local t
+local <?value?> = t.value
+]]
+
+TEST 'boolean' [[
+---@class GenericSuper<T>: { value: T }
+---@class Specific: GenericSuper<string>
+---@field value boolean
+---@type Specific
+local t
+local <?value?> = t.value
+]]
+
+TEST 'string' [[
+---@class GenericSuper<T>: { value: T }
+---@type GenericSuper<string>
+local t
+local <?value?> = t.value
+]]
diff --git a/test/type_inference/init.lua b/test/type_inference/init.lua
index 0236f7e9f..a87a58018 100644
--- a/test/type_inference/init.lua
+++ b/test/type_inference/init.lua
@@ -47,4 +47,5 @@ end
 require 'type_inference.common'
 require 'type_inference.param_match'
 require 'type_inference.field_override'
+require 'type_inference.inherited_table_fields'
 require 'type_inference.generic_operator'