Add some basic compile-time checks to enforce usage of `T{...}` within traits

2 files changed, 11 insertions, 0 deletions

diff --git a/core/src/test/scala/forge/CacherTests.scala b/core/src/test/scala/forge/CacherTests.scala
index 4c346e5e..c6157a4a 100644
--- a/core/src/test/scala/forge/CacherTests.scala
+++ b/core/src/test/scala/forge/CacherTests.scala
@@ -46,5 +46,15 @@ object CacherTests extends TestSuite{
       eval(Terminal, Terminal.value) == 7,
       eval(Terminal, Terminal.overriden) == 1
     )
+    'errors{
+      val expectedMsg =
+        "T{} can only be used directly within a zero-arg method defined in a class body"
+
+      val err1 = compileError("object Foo extends Target.Cacher{ val x = T{1} }")
+      assert(err1.msg == expectedMsg)
+
+      val err2 = compileError("object Foo extends Target.Cacher{ def x = {def y = T{1}} }")
+      assert(err2.msg == expectedMsg)
+    }
   }
 }
diff --git a/core/src/test/scala/forge/TestGraphs.scala b/core/src/test/scala/forge/TestGraphs.scala
index 5960ed4c..0d6040eb 100644
--- a/core/src/test/scala/forge/TestGraphs.scala
+++ b/core/src/test/scala/forge/TestGraphs.scala
@@ -100,3 +100,4 @@ class TestGraphs(){
     val j = test(test(i), test(i, f), test(f))
   }
 }
+