fix: preserve inherited generic table fields

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`

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

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 }
 

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

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
+]]

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'