diff --git a/src/typing/tests.rs b/src/typing/tests.rs
new file mode 100644
index 0000000..e579554
--- /dev/null
+++ b/src/typing/tests.rs
@@ -0,0 +1,33 @@
+use crate::{
+    ast::ModulePath,
+    parsing::parse_as_module,
+    typing::{
+        error::{TypeError, TypeErrorKind},
+        BinaryOperator, Type,
+    },
+};
+
+#[test]
+fn addition_int_and_float() {
+    let source = "fn add(a: int, b: float) int { a + b }";
+    let mut ast = parse_as_module(source, ModulePath::default()).unwrap();
+    let res = ast.type_check();
+    assert!(res.is_err_and(|e| e.kind
+        == TypeErrorKind::InvalidBinaryOperator {
+            operator: BinaryOperator::Add,
+            lht: Type::Int,
+            rht: Type::Float
+        }));
+}
+
+#[test]
+fn return_int_instead_of_float() {
+    let source = "fn add(a: int, b: int) float { a + b }";
+    let mut ast = parse_as_module(source, ModulePath::default()).unwrap();
+    let res = ast.type_check();
+    assert!(res.is_err_and(|e| e.kind
+        == TypeErrorKind::BlockTypeDoesNotMatchFunctionType {
+            block_type: Type::Int,
+            function_type: Type::Float
+        }));
+}