refactor: Move tests of ast in separate folder

lib/ast/dune

@@ -0,0 +1,3 @@
+(library
+ (name ast)
+ (modules syntax print))

lib/dune

@@ -10,10 +10,6 @@
  (modules parser)
  (libraries ast))
 
-(library
- (name ast)
- (modules ast))
-
 (menhir
  (modules parser))
 

test/ast/print.ml

@@ -1,7 +1,8 @@
-(* test/ast.ml *)
+(* test/print.ml *)
 
 open Alcotest
-open Ast
+open Ast.Syntax
+open Ast.Print
 
 let test_string_of_binary_operator () =
   check string "+" "Add" (string_of_binary_operator Add);
@@ -9,6 +10,9 @@ let test_string_of_binary_operator () =
   check string "*" "Multiply" (string_of_binary_operator Multiply);
   check string "/" "Divide" (string_of_binary_operator Divide)
 
+let test_string_of_unary_operator () =
+  check string "-" "Negate" (string_of_unary_operator Negate)
+
 let test_string_of_expression () =
   let expr = BinaryExpression (Add, IntegerLiteral 1, IntegerLiteral 2) in
   check string "1 + 2"
@@ -39,6 +43,11 @@ let () =
   let open Alcotest in
   run "AST tests"
     [
+      ( "string_of_unary_operator",
+        [
+          test_case "string_of_unary_operator" `Quick
+            test_string_of_unary_operator;
+        ] );
       ( "string_of_binary_operator",
         [
           test_case "string_of_binary_operator" `Quick

test/dune

@@ -1,5 +1 @@
 ;test/dune
-
-(test
- (name ast)
- (libraries ast alcotest))