Add a test suite for milestone examples (#1920)

In this PR I will add tests for the example programs in
`examples/milestone`.

There's currently an runtime assertion error generated by the Hanoi
example https://github.com/anoma/juvix/issues/1919, so it'd be good to
test these programs in the future.

examples/milestone/Collatz/Collatz.juvix

@@ -1,42 +1,34 @@
 module Collatz;
 
 open import Stdlib.Prelude;
-
-mapMaybe :
-  {A : Type} → {B : Type} → (A → B) → Maybe A → Maybe B;
-mapMaybe _ nothing := nothing;
-mapMaybe f (just x) := just (f x);
-
-div2 : Nat → Maybe Nat;
-div2 zero := just zero;
-div2 (suc (suc n)) := mapMaybe suc (div2 n);
-div2 _ := nothing;
+open import Stdlib.Data.Nat.Ord;
 
 collatzNext : Nat → Nat;
-collatzNext n := fromMaybe (suc (3 * n)) (div2 n);
+collatzNext n := if (mod n 2 == 0) (div n 2) (3 * n + 1);
 
 collatz : Nat → Nat;
 collatz zero := zero;
 collatz (suc zero) := suc zero;
-collatz (suc (suc n)) := collatzNext (suc (suc n));
-
---- -----------------------------------------------------------------------------
-
--- IO
---- -----------------------------------------------------------------------------
-output : Nat → Nat × IO;
-output n := n, printNatLn n;
+collatz n := collatzNext n;
 
 terminating
 run : (Nat → Nat) → Nat → IO;
-run _ (suc zero) := printStringLn "Finished!";
-run f n := run f (fst (output (f n)));
+run _ (suc zero) :=
+  printNatLn 1 >> printStringLn "Finished!";
+run f n := printNatLn n >> run f (f n);
 
 welcome : String;
 welcome :=
   "Collatz calculator\n------------------\n\nType a number then ENTER";
 
+resultHeading : String;
+resultHeading := "Collatz sequence:";
+
 main : IO;
 main :=
   printStringLn welcome
-    >> readLn (run collatz ∘ stringToNat);
+    >> readLn
+      λ {
+        | s := printStringLn resultHeading
+          >> run collatz (stringToNat s)
+      };

examples/milestone/Fibonacci/Fibonacci.juvix

@@ -10,4 +10,4 @@ fibonacci : Nat → Nat;
 fibonacci n := fib n 0 1;
 
 main : IO;
-main := printNatLn (fibonacci 25);
+main := readLn (printNatLn ∘ fibonacci ∘ stringToNat);

test/Examples.hs

@@ -0,0 +1,7 @@
+module Examples where
+
+import Base
+import Examples.Positive qualified as P
+
+allTests :: TestTree
+allTests = testGroup "Juvix milestone examples compilation tests" [P.allTests]

test/Examples/Positive.hs

@@ -0,0 +1,87 @@
+module Examples.Positive where
+
+import Base
+import Compilation.Base
+
+data PosTest = PosTest
+  { _name :: String,
+    _dir :: Path Abs Dir,
+    _file :: Path Abs File,
+    _expectedFile :: Path Abs File,
+    _stdin :: Text
+  }
+
+makeLenses ''PosTest
+
+srcRoot :: Path Abs Dir
+srcRoot = relToProject $(mkRelDir "examples/")
+
+expectedRoot :: Path Abs Dir
+expectedRoot = relToProject $(mkRelDir "tests/examplesExpected")
+
+toTestDescr :: PosTest -> TestDescr
+toTestDescr PosTest {..} =
+  TestDescr
+    { _testRoot = _dir,
+      _testName = _name,
+      _testAssertion = Steps $ compileAssertion (CompileOnly _stdin) _file _expectedFile
+    }
+
+allTests :: TestTree
+allTests =
+  testGroup
+    "Compile and test examples"
+    (map (mkTest . toTestDescr) tests)
+
+posTest :: String -> Path Rel Dir -> Path Rel File -> Path Rel File -> Text -> PosTest
+posTest _name rdir rfile routfile _stdin =
+  let _dir = srcRoot <//> rdir
+      _file = _dir <//> rfile
+      _expectedFile = expectedRoot <//> routfile
+   in PosTest {..}
+
+tests :: [PosTest]
+tests =
+  [ posTest
+      "Fibonacci"
+      $(mkRelDir "milestone/Fibonacci")
+      $(mkRelFile "Fibonacci.juvix")
+      $(mkRelFile "Fibonacci/expected.golden")
+      "25\n",
+    posTest
+      "Hello World"
+      $(mkRelDir "milestone/HelloWorld")
+      $(mkRelFile "HelloWorld.juvix")
+      $(mkRelFile "HelloWorld/expected.golden")
+      "",
+    posTest
+      "Collatz calculator"
+      $(mkRelDir "milestone/Collatz")
+      $(mkRelFile "Collatz.juvix")
+      $(mkRelFile "Collatz/expected.golden")
+      "123\n",
+    posTest
+      "Pascal's triangle"
+      $(mkRelDir "milestone/PascalsTriangle")
+      $(mkRelFile "PascalsTriangle.juvix")
+      $(mkRelFile "PascalsTriangle/expected.golden")
+      "",
+    posTest
+      "Demo"
+      $(mkRelDir "demo")
+      $(mkRelFile "Demo.juvix")
+      $(mkRelFile "Demo/expected.golden")
+      "",
+    posTest
+      "TicTacToe"
+      $(mkRelDir "milestone/TicTacToe")
+      $(mkRelFile "CLI/TicTacToe.juvix")
+      $(mkRelFile "TicTacToe/expected.golden")
+      "aaa\n0\n10\n1\n2\n3\n3\n4\n5\n6\n7\n8\n9\n",
+    posTest
+      "Towers of Hanoi"
+      $(mkRelDir "milestone/Hanoi")
+      $(mkRelFile "Hanoi.juvix")
+      $(mkRelFile "Hanoi/expected.golden")
+      ""
+  ]

test/Main.hs

@@ -6,6 +6,7 @@ import BackendGeb qualified
 import Base
 import Compilation qualified
 import Core qualified
+import Examples qualified
 import Format qualified
 import Internal qualified
 import Parsing qualified
@@ -24,7 +25,8 @@ slowTests =
       Asm.allTests,
       Core.allTests,
       Internal.allTests,
-      Compilation.allTests
+      Compilation.allTests,
+      Examples.allTests
     ]
 
 fastTests :: TestTree

tests/examplesExpected/Collatz/expected.golden

@@ -2,6 +2,8 @@ Collatz calculator
 ------------------
 
 Type a number then ENTER
+Collatz sequence:
+123
 370
 185
 556

tests/examplesExpected/Demo/expected.golden

@@ -0,0 +1,5 @@
+Hello!
+2 :: 7 :: 3 :: 1 :: 0 :: nil
+0 :: 1 :: 2 :: 3 :: 7 :: nil
+1
+7

tests/examplesExpected/HelloWorld/expected.golden

@@ -0,0 +1 @@
+hello world!