💕 Adding assignment 3

a3/a3-handout/src/APL/Parser_Tests.hs

@@ -0,0 +1,68 @@
+module APL.Parser_Tests (tests) where
+
+import APL.AST (Exp (..))
+import APL.Parser (parseAPL)
+import Test.Tasty (TestTree, testGroup)
+import Test.Tasty.HUnit (assertFailure, testCase, (@?=))
+
+parserTest :: String -> Exp -> TestTree
+parserTest s e =
+  testCase s $
+    case parseAPL "input" s of
+      Left err -> assertFailure err
+      Right e' -> e' @?= e
+
+parserTestFail :: String -> TestTree
+parserTestFail s =
+  testCase s $
+    case parseAPL "input" s of
+      Left _ -> pure ()
+      Right e ->
+        assertFailure $
+          "Expected parse error but received this AST:\n" ++ show e
+
+tests :: TestTree
+tests =
+  testGroup
+    "Parsing"
+    [ testGroup
+        "Constants"
+        [ parserTest "123" $ CstInt 123,
+          parserTest " 123" $ CstInt 123,
+          parserTest "123 " $ CstInt 123,
+          parserTestFail "123f",
+          parserTest "true" $ CstBool True,
+          parserTest "false" $ CstBool False
+        ],
+      testGroup
+        "Basic operators"
+        [ parserTest "x+y" $ Add (Var "x") (Var "y"),
+          parserTest "x-y" $ Sub (Var "x") (Var "y"),
+          parserTest "x*y" $ Mul (Var "x") (Var "y"),
+          parserTest "x/y" $ Div (Var "x") (Var "y")
+        ],
+      testGroup
+        "Operator priority"
+        [ parserTest "x+y+z" $ Add (Add (Var "x") (Var "y")) (Var "z"),
+          parserTest "x+y-z" $ Sub (Add (Var "x") (Var "y")) (Var "z"),
+          parserTest "x+y*z" $ Add (Var "x") (Mul (Var "y") (Var "z")),
+          parserTest "x*y*z" $ Mul (Mul (Var "x") (Var "y")) (Var "z"),
+          parserTest "x/y/z" $ Div (Div (Var "x") (Var "y")) (Var "z")
+        ],
+      testGroup
+        "Conditional expressions"
+        [ parserTest "if x then y else z" $ If (Var "x") (Var "y") (Var "z"),
+          parserTest "if x then y else if x then y else z" $
+            If (Var "x") (Var "y") $
+              If (Var "x") (Var "y") (Var "z"),
+          parserTest "if x then (if x then y else z) else z" $
+            If (Var "x") (If (Var "x") (Var "y") (Var "z")) (Var "z"),
+          parserTest "1 + if x then y else z" $
+            Add (CstInt 1) (If (Var "x") (Var "y") (Var "z"))
+        ],
+      testGroup
+        "Lexing edge cases"
+        [ parserTest "2 " $ CstInt 2,
+          parserTest " 2" $ CstInt 2
+        ]
+    ]