Basic types allow contravariance

Author: sumneko

changelog.md

@@ -13,6 +13,16 @@
   local function callback(a) end  --> a: integer
   register(callback)
   ```
+* `CHG` Basic types allow contravariance
+  ```lua
+  ---@class int32: integer
+
+  ---@type integer
+  local n
+
+  ---@type int32
+  local a = n
+  ```
 
 ## 3.12.0
 `2024-10-30`

script/vm/type.lua

@@ -584,9 +584,11 @@ function vm.isSubType(uri, child, parent, mark, errs)
     local x = '' --> `string` set to `A`
     ]]
     if  guide.isBasicType(childName)
-    and guide.isLiteral(child)
-    and vm.isSubType(uri, parentName, childName, mark) then
-        return true
+    and not mark[childName] then
+        mark[childName] = true
+        if vm.isSubType(uri, parentName, childName, mark) then
+            return true
+        end
     end
 
     if errs then

test/diagnostics/param-type-mismatch.lua

@@ -352,4 +352,16 @@ function f(a) end
 f(a)
 ]]
 
+TEST [[
+---@class A: integer
+
+---@param a A
+local function f(a) end
+
+---@type integer
+local i
+
+f(i)
+]]
+
 config.set(nil, 'Lua.type.checkTableShape', false)