implemented simple evaluator for program,

statements and integer literals, together with
tests

test/utils/fixtures.cpp

@@ -1,3 +1,5 @@
+#include "evaluator/evaluator.hpp"
+#include "object/object.hpp"
 #include "utils.hpp"
 
 #include <doctest.h>
@@ -30,4 +32,9 @@ namespace test::utils {
             "parse_program() returned a null pointer"
         );
     }
+
+    void EvalFixture::setup(std::string source) {
+        ParserFixture::setup(source);
+        result = std::unique_ptr<object::object>(eval::eval(program.get()));
+    }
 } // namespace test::utils

test/utils/test_eval.cpp

@@ -0,0 +1,10 @@
+#include "object/integers.hpp"
+#include "object/object.hpp"
+#include "utils.hpp"
+
+namespace test::utils {
+    void test_integer_object(object::object* obj, int expected) {
+        object::integer* i = cast<object::integer>(obj);
+        CHECK(i->value == expected);
+    }
+} // namespace test::utils

test/utils/utils.hpp

@@ -2,6 +2,7 @@
 
 #include "ast/ast.hpp"
 #include "lexer/lexer.hpp"
+#include "object/object.hpp"
 #include "parser/parser.hpp"
 
 #include <any>
@@ -21,9 +22,15 @@ namespace test::utils {
 
         ParserFixture() = default;
 
+        virtual void setup(std::string);
+    };
+
+    struct EvalFixture : ParserFixture {
+        std::unique_ptr<object::object> result;
         void setup(std::string);
     };
 
+    // parser tests
     void test_identifier(ast::expression*, std::string);
     void test_integer_literal(ast::expression*, int);
     void test_boolean_literal(ast::expression*, bool);
@@ -32,6 +39,9 @@ namespace test::utils {
     test_infix_expression(ast::expression*, std::any, std::string, std::any);
     void test_failing_parsing(std::string, std::vector<token::type>, int = 0);
 
+    // eval tests
+    void test_integer_object(object::object*, int);
+
     namespace {
 
         std::string demangle(const char* name) {
@@ -73,4 +83,9 @@ namespace test::utils {
         return cast_impl<T, ast::error::error>(err);
     }
 
+    template <typename T>
+    T* cast(object::object* err) {
+        return cast_impl<T, object::object>(err);
+    }
+
 } // namespace test::utils