don't check t.field = nil

Author: sumneko

script/core/diagnostics/assign-type-mismatch.lua

@@ -15,6 +15,21 @@ local checkTypes = {
     'tableindex'
 }
 
+---@param source parser.object
+---@return boolean
+local function hasMarkType(source)
+    if not source.bindDocs then
+        return false
+    end
+    for _, doc in ipairs(source.bindDocs) do
+        if doc.type == 'doc.type'
+        or doc.type == 'doc.class' then
+            return true
+        end
+    end
+    return false
+end
+
 ---@async
 return function (uri, callback)
     local state = files.getState(uri)
@@ -35,11 +50,24 @@ return function (uri, callback)
                 return
             end
         end
+        --[[
+        ---@class A
+        local mt
+        ---@type X
+        mt._x = nil -- don't warn this
+        ]]
+        if value.type == 'nil' then
+            if hasMarkType(source) then
+                return
+            end
+        end
+
         local valueNode = vm.compileNode(value)
         if source.type == 'setindex' then
             -- boolean[1] = nil
             valueNode = valueNode:copy():removeOptional()
         end
+
         local varNode = vm.compileNode(source)
         if vm.canCastType(uri, varNode, valueNode) then
             return

script/parser/guide.lua

@@ -14,7 +14,7 @@ local type         = type
 ---@field locals                parser.object[]
 ---@field returns?              parser.object[]
 ---@field exps                  parser.object[]
----@field keys                  parser.object[]
+---@field keys                  parser.object
 ---@field uri                   uri
 ---@field start                 integer
 ---@field finish                integer

script/parser/luadoc.lua

@@ -143,6 +143,7 @@ Symbol              <-  ({} {
 ---@field originalComment parser.object
 ---@field as? parser.object
 ---@field touch? integer
+---@field module? string
 
 local function trim(str)
     return str:match '^%s*(%S+)%s*$'

script/vm/compiler.lua

@@ -14,10 +14,15 @@ local vm         = require 'vm.vm'
 ---@field func            parser.object
 
 -- 该函数有副作用，会给source绑定node！
+---@param source parser.object
+---@return boolean
 local function bindDocs(source)
+    local docs = source.bindDocs
+    if not docs then
+        return false
+    end
     local isParam = source.parent.type == 'funcargs'
                  or (source.parent.type == 'in' and source.finish <= source.parent.keys.finish)
-    local docs = source.bindDocs
     for i = #docs, 1, -1 do
         local doc = docs[i]
         if doc.type == 'doc.type' then
@@ -47,6 +52,9 @@ local function bindDocs(source)
         end
         if doc.type == 'doc.module' then
             local name = doc.module
+            if not name then
+                return true
+            end
             local uri = rpath.findUrisByRequirePath(guide.getUri(source), name)[1]
             if not uri then
                 return true
@@ -1380,9 +1388,18 @@ local compilerSwitch = util.switch()
         else
             ---@cast key string
             vm.compileByParentNode(source.node, key, false, function (src)
-                vm.setNode(source, vm.compileNode(src))
                 if src.value then
-                    vm.setNode(source, vm.compileNode(src.value))
+                    if bindDocs(src) then
+                        vm.setNode(source, vm.compileNode(src))
+                    else
+                        vm.setNode(source, vm.compileNode(src.value))
+                        local node = vm.getNode(src)
+                        if node then
+                            vm.setNode(source, node)
+                        end
+                    end
+                else
+                    vm.setNode(source, vm.compileNode(src))
                 end
             end)
         end

test/diagnostics/type-check.lua

@@ -599,5 +599,15 @@ function F()
 end
 ]]
 
+TEST [[
+---@class X
+
+---@class A
+local mt = G
+
+---@type X
+mt._x = nil
+]]
+
 config.remove(nil, 'Lua.diagnostics.disable', 'unused-local')
 config.remove(nil, 'Lua.diagnostics.disable', 'undefined-global')