Add closure tests

test/functions.cpp

@@ -110,5 +110,47 @@ int main() {
         true
     );
 
+    _TEST_ASSERT(
+        _TEST_NO_EXCEPTION(get<int>(execute(R"(
+            int x = 1;
+            int a() {
+                return x;
+            }
+            int b() {
+                int x = 2;
+                return a();
+            }
+            b();
+            )")) == 1),
+        "Closure capture",
+        true
+    );
+
+    _TEST_ASSERT(
+        _TEST_NO_EXCEPTION(get<int>(execute(R"(
+            int x = 1;
+            int a() {
+                return x;
+            }
+            x = 2;
+            a();
+            )")) == 2),
+        "Closure mutation externe",
+        true
+    );
+
+    _TEST_ASSERT(
+        _TEST_NO_EXCEPTION(get<int>(execute(R"(
+            int x = 1;
+            void a() {
+                x = 2;
+            }
+            a();
+            x;
+            )")) == 2),
+        "Closure mutation interne",
+        true
+    );
+
     return 0;
 }