Fix incorrect type generated for Union(...)

crystal-lang · Jun 6, 2016 · 3d20332 · 3d20332
1 parent 1749358
commit 3d20332
Showing 3 changed files with 30 additions and 1 deletion.
diff --git a/spec/compiler/type_inference/splat_spec.cr b/spec/compiler/type_inference/splat_spec.cr
@@ -437,6 +437,26 @@ describe "Type inference: splat" do
       )) { int32 }
   end
 
+  it "accesses T when empty, via module" do
+    assert_type(%(
+      module Moo(T)
+        def t
+          T
+        end
+      end
+
+      struct Tuple
+        include Moo(Union(*T))
+
+        def self.new(*args)
+          args
+        end
+      end
+
+      Tuple.new.t
+      )) { no_return.metaclass }
+  end
+
   describe Splat do
     it "without splat" do
       a_def = Def.new("foo", args: [Arg.new("x"), Arg.new("y")])

diff --git a/spec/compiler/type_inference/union_spec.cr b/spec/compiler/type_inference/union_spec.cr
@@ -140,4 +140,13 @@ describe "Type inference: union" do
       Union(Int32, String).foo
       )) { int32 }
   end
+
+  it "merges types in the same hierarchy with Union" do
+    assert_type(%(
+      class Foo; end
+      class Bar < Foo; end
+
+      Union(Foo, Bar)
+      )) { types["Foo"].virtual_type!.metaclass }
+  end
 end
diff --git a/src/compiler/crystal/types.cr b/src/compiler/crystal/types.cr
@@ -2656,7 +2656,7 @@ module Crystal
         end
         type_var
       end
-      program.type_merge_union_of(types).not_nil!
+      program.type_merge(types) || program.no_return
     end
 
     def new_generic_instance(program, generic_type, type_vars)