search fields by chain exp

resolve #1222

Author: sumneko

script/vm/field.lua

@@ -24,11 +24,19 @@ local function searchByLocalID(source, pushResult)
     end
 end
 
-local function searchByNode(source, pushResult)
+local function searchByNode(source, pushResult, mark)
+    mark = mark or {}
+    if mark[source] then
+        return
+    end
+    mark[source] = true
     local uri = guide.getUri(source)
     vm.compileByParentNode(source, nil, true, function (field)
         searchByNodeSwitch(field.type, uri, field, pushResult)
     end)
+    vm.compileByNodeChain(source, function (src)
+        searchByNode(src, pushResult, mark)
+    end)
 end
 
 ---@param source parser.object

test/completion/common.lua

@@ -3777,3 +3777,21 @@ acceptOptions({
 (function (results)
     assert(#results == 2)
 end)
+
+TEST [[
+local t1 = {}
+
+t1.A = {}
+t1.A.B = {}
+t1.A.B.C = 1
+
+local t2 = t1
+
+print(t2.A.<??>)
+]]
+{
+    {
+        label    = 'B',
+        kind     = define.CompletionItemKind.Field,
+    },
+}