search definitions by 1st arg of setmetatable

resolve #1575

Author: sumneko

changelog.md

@@ -37,6 +37,15 @@ server will generate `doc.json` and `doc.md` in `LOGPATH`.
   * `return-type-mismatch`
 * `CHG` workspace-symbol: supports chain fields based on global variables and types. try `io.open` or `iolib.open`
 * `CHG` [#1641] if a function only has varargs and has `---@overload`, the varargs will be ignored
+* `CHG` [#1575] search definitions by first argument of `setmetatable`
+  ```lua
+  ---@class Object
+  local obj = setmetatable({
+    initValue = 1,
+  }, mt)
+
+  print(obj.initValue) --> `obj.initValue` is integer
+  ```
 * `FIX` [#1567]
 * `FIX` [#1593]
 * `FIX` [#1595]
@@ -53,6 +62,7 @@ server will generate `doc.json` and `doc.md` in `LOGPATH`.
 [#1558]: https://github.com/sumneko/lua-language-server/issues/1558
 [#1561]: https://github.com/sumneko/lua-language-server/issues/1561
 [#1567]: https://github.com/sumneko/lua-language-server/issues/1567
+[#1575]: https://github.com/sumneko/lua-language-server/issues/1575
 [#1582]: https://github.com/sumneko/lua-language-server/issues/1582
 [#1593]: https://github.com/sumneko/lua-language-server/issues/1593
 [#1595]: https://github.com/sumneko/lua-language-server/issues/1595

script/vm/compiler.lua

@@ -368,6 +368,27 @@ function vm.getClassFields(suri, object, key, ref, pushResult)
                             end
                         end)
                     end
+                    if  src.value
+                    and src.value.type == 'select'
+                    and src.value.vararg.type == 'call' then
+                        local func = src.value.vararg.node
+                        local args = src.value.vararg.args
+                        if  func.special == 'setmetatable'
+                        and args
+                        and args[1]
+                        and args[1].type == 'table' then
+                            searchFieldSwitch('table', suri, args[1], key, ref, function (field)
+                                local fieldKey = guide.getKeyName(field)
+                                if fieldKey then
+                                    if  not searchedFields[fieldKey]
+                                    and guide.isSet(field) then
+                                        hasFounded[fieldKey] = true
+                                        --pushResult(field, true)
+                                    end
+                                end
+                            end)
+                        end
+                    end
                     copyToSearched()
                     searchFieldSwitch(src.type, suri, src, key, ref, function (field)
                         local fieldKey = guide.getKeyName(field)

test/diagnostics/type-check.lua

@@ -841,6 +841,20 @@ TEST [[
 local <!test!> = 4
 ]]
 
+TEST [[
+---@class MyClass
+local MyClass = {}
+
+function MyClass:new()
+    ---@class MyClass
+    local myObject = setmetatable({
+        initialField = true
+    }, self)
+
+    print(myObject.initialField)
+end
+]]
+
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-local')
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-function')
 config.remove(nil, 'Lua.diagnostics.disable', 'undefined-global')