💕 Adding assignment 2

a2/a2-handout/src/APL/Check_Tests.hs

@@ -0,0 +1,26 @@
+module APL.Check_Tests (tests) where
+
+import APL.AST (Exp (..))
+import APL.Check (checkExp)
+import Test.Tasty (TestTree, testGroup)
+import Test.Tasty.HUnit (assertFailure, testCase, (@?=))
+
+-- Assert that the provided expression should pass the type checker.
+testPos :: Exp -> TestTree
+testPos e =
+  testCase (show e) $
+    checkExp e @?= Nothing
+
+-- Assert that the provided expression should fail the type checker.
+testNeg :: Exp -> TestTree
+testNeg e =
+  testCase (show e) $
+    case checkExp e of
+      Nothing -> assertFailure "expected error"
+      Just _ -> pure ()
+
+tests :: TestTree
+tests =
+  testGroup
+    "Checking"
+    []