fix: resolve type parameter in setmetatable using nested records

Fixes #772.
teal-language · Oct 13, 2024 · ede28c9 · ede28c9
1 parent 1ed3598
commit ede28c9
Show file tree

Hide file tree

Showing 3 changed files with 22 additions and 0 deletions.
diff --git a/spec/lang/stdlib/setmetatable_spec.lua b/spec/lang/stdlib/setmetatable_spec.lua
@@ -27,4 +27,18 @@ describe("setmetatable", function()
       print(r("!!!", 1000)) -- prints 12000!!!
       print((r + s).x)      -- prints 32
    ]]))
+
+   it("works with nested records (regression test for #772", util.check([[
+      local record Wrapper
+          record Inner
+              metamethod __call: function(container: Inner, instance: Inner): Inner
+          end
+      end
+
+      setmetatable(Wrapper.Inner, {
+          __call = function(container: Wrapper.Inner, instance: Wrapper.Inner): Wrapper.Inner
+              return setmetatable(instance, {__index = container})
+          end
+      })
+   ]]))
 end)
diff --git a/tl.lua b/tl.lua
@@ -8590,6 +8590,10 @@ do
       },
       ["nominal"] = {
          ["nominal"] = TypeChecker.are_same_nominals,
+         ["typedecl"] = function(self, a, b)
+
+            return self:same_type(self:resolve_nominal(a), b.def)
+         end,
       },
       ["record"] = {
          ["record"] = TypeChecker.eqtype_record,

diff --git a/tl.tl b/tl.tl
@@ -8590,6 +8590,10 @@ do
       },
       ["nominal"] = {
          ["nominal"] = TypeChecker.are_same_nominals,
+         ["typedecl"] = function(self: TypeChecker, a: NominalType, b: TypeDeclType): boolean, {Error}
+            -- used when resolving type parameters
+            return self:same_type(self:resolve_nominal(a), b.def)
+         end,
       },
       ["record"] = {
          ["record"] = TypeChecker.eqtype_record,