From 2f97522e12728423f339f90bf70c334d382702c3 Mon Sep 17 00:00:00 2001
From: JaDogg <JaDogg@users.noreply.github.com>
Date: Mon, 19 Jun 2023 06:06:41 +0100
Subject: [PATCH] fix(type_checker,tests): handle redefining variables in
 type_checker

---
 compiler/src/compiler/type_checker.cpp                   | 3 +++
 compiler/test_data/bug_fixes/redefining_vars.yaka        | 7 +++++++
 compiler/test_data/bug_fixes/redefining_vars_params.yaka | 7 +++++++
 compiler/tests/test_type_checker.cpp                     | 8 ++++++++
 4 files changed, 25 insertions(+)
 create mode 100644 compiler/test_data/bug_fixes/redefining_vars.yaka
 create mode 100644 compiler/test_data/bug_fixes/redefining_vars_params.yaka

diff --git a/compiler/src/compiler/type_checker.cpp b/compiler/src/compiler/type_checker.cpp
index 262bbdea..f7c9f758 100644
--- a/compiler/src/compiler/type_checker.cpp
+++ b/compiler/src/compiler/type_checker.cpp
@@ -457,6 +457,9 @@ void type_checker::visit_if_stmt(if_stmt *obj) {
 }
 void type_checker::visit_let_stmt(let_stmt *obj) {
   auto name = obj->name_->token_;
+  if (scope_.is_defined(name)) {
+    error(obj->name_, "Redefining a variable is not allowed");
+  }
   auto placeholder = ykobject(obj->data_type_);
   if (obj->expression_ != nullptr) {
     obj->expression_->accept(this);
diff --git a/compiler/test_data/bug_fixes/redefining_vars.yaka b/compiler/test_data/bug_fixes/redefining_vars.yaka
new file mode 100644
index 00000000..69c62436
--- /dev/null
+++ b/compiler/test_data/bug_fixes/redefining_vars.yaka
@@ -0,0 +1,7 @@
+def a() -> int:
+    b: int = 1
+    b: u8 = 1u8
+    return 0
+
+def main() -> int:
+    return 0
diff --git a/compiler/test_data/bug_fixes/redefining_vars_params.yaka b/compiler/test_data/bug_fixes/redefining_vars_params.yaka
new file mode 100644
index 00000000..4921bcac
--- /dev/null
+++ b/compiler/test_data/bug_fixes/redefining_vars_params.yaka
@@ -0,0 +1,7 @@
+def a(b: int) -> int:
+    b: u8 = 1u8
+    return 0
+
+def main() -> int:
+    a(1)
+    return 0
diff --git a/compiler/tests/test_type_checker.cpp b/compiler/tests/test_type_checker.cpp
index 4f620b35..8b616110 100644
--- a/compiler/tests/test_type_checker.cpp
+++ b/compiler/tests/test_type_checker.cpp
@@ -481,4 +481,12 @@ TEST_CASE(
     "type checker: only 1 argument is allowed for binarydata()") {
   TEST_SNIPPET("a: Ptr[Const[u8]] = binarydata(1, 2, 3)",
                "binarydata() builtin expects 1 argument");
+}
+TEST_CASE("type checker: Redefining variables in a function different data types") {
+  TEST_FILE("../test_data/bug_fixes/redefining_vars.yaka",
+            "Redefining a variable is not allowed");
+}
+TEST_CASE("type checker: Redefining variables in a function - params") {
+  TEST_FILE("../test_data/bug_fixes/redefining_vars_params.yaka",
+            "Redefining a variable is not allowed");
 }
\ No newline at end of file