feat: Support basic expression

test/ast.ml

@@ -0,0 +1,54 @@
+(* test/ast.ml *)
+
+open Alcotest
+open Ast
+
+let test_string_of_binary_operator () =
+  check string "+" "Add" (string_of_binary_operator Add);
+  check string "-" "Substract" (string_of_binary_operator Substract);
+  check string "*" "Multiply" (string_of_binary_operator Multiply);
+  check string "/" "Divide" (string_of_binary_operator Divide)
+
+let test_string_of_expression () =
+  let expr = BinaryExpression (Add, IntegerLiteral 1, IntegerLiteral 2) in
+  check string "1 + 2"
+    "BinaryExpression(Add, IntegerLiteral(1), IntegerLiteral(2))"
+    (string_of_expression expr)
+
+let test_string_of_statement () =
+  let stmt = ExpressionStatement (IntegerLiteral 42) in
+  check string "42;" "ExpressionStatement(IntegerLiteral(42))"
+    (string_of_statement stmt)
+
+let test_string_of_source_file () =
+  let source_file =
+    SourceFile
+      [
+        ExpressionStatement (IntegerLiteral 1);
+        ExpressionStatement
+          (BinaryExpression (Add, IntegerLiteral 2, IntegerLiteral 3));
+      ]
+  in
+  check string "1; 2 + 3;"
+    "SourceFile([ExpressionStatement(IntegerLiteral(1)), \
+     ExpressionStatement(BinaryExpression(Add, IntegerLiteral(2), \
+     IntegerLiteral(3)))])"
+    (string_of_source_file source_file)
+
+let () =
+  let open Alcotest in
+  run "AST tests"
+    [
+      ( "string_of_binary_operator",
+        [
+          test_case "string_of_binary_operator" `Quick
+            test_string_of_binary_operator;
+        ] );
+      ( "string_of_expression",
+        [ test_case "string_of_expression" `Quick test_string_of_expression ] );
+      ( "string_of_statement",
+        [ test_case "string_of_statement" `Quick test_string_of_statement ] );
+      ( "string_of_source_file",
+        [ test_case "string_of_source_file" `Quick test_string_of_source_file ]
+      );
+    ]

test/dune

@@ -1,2 +1,5 @@
+;test/dune
+
 (test
- (name croissant))
+ (name ast)
+ (libraries ast alcotest))