added tests for the stringification of the program

test/program.cpp

@@ -0,0 +1,38 @@
+#include "ast/program.hpp"
+
+#include "ast/ast.hpp"
+#include "ast/statements/let.hpp"
+#include "ast/statements/return.hpp"
+#include "token/type.hpp"
+
+#include <doctest.h>
+
+TEST_SUITE("Program") {
+    TEST_CASE("Let string") {
+        ast::program program({new ast::let_stmt(
+            token::token(token::type::LET, "let"),
+            new ast::identifier(
+                token::token(token::type::IDENTIFIER, "myVar"),
+                "myVar"
+            ),
+            new ast::identifier(
+                token::token(token::type::IDENTIFIER, "anotherVar"),
+                "anotherVar"
+            )
+        )});
+
+        CHECK(program.str() == "let myVar = anotherVar;");
+    }
+
+    TEST_CASE("Return string") {
+        ast::program program({new ast::return_stmt(
+            token::token(token::type::RETURN, "return"),
+            new ast::identifier(
+                token::token(token::type::IDENTIFIER, "myVar"),
+                "myVar"
+            )
+        )});
+
+        CHECK(program.str() == "return myVar;");
+    }
+}