diff --git a/tests/test_set_var.h b/tests/test_set_var.h
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+++ b/tests/test_set_var.h
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+/**
+ * test_set_var.h
+ * =============================================================================
+ * Copyright 2021-2023 Serhii Snitsaruk
+ *
+ * Use of this source code is governed by an MIT-style
+ * license that can be found in the LICENSE file or at
+ * https://opensource.org/licenses/MIT.
+ * =============================================================================
+ */
+
+#ifndef TEST_SET_VAR_H
+#define TEST_SET_VAR_H
+
+#include "core/variant/variant.h"
+#include "limbo_test.h"
+
+#include "modules/limboai/blackboard/bb_param/bb_param.h"
+#include "modules/limboai/blackboard/bb_param/bb_variant.h"
+#include "modules/limboai/blackboard/blackboard.h"
+#include "modules/limboai/bt/tasks/blackboard/bt_set_var.h"
+#include "modules/limboai/bt/tasks/bt_task.h"
+#include "tests/test_macros.h"
+
+namespace TestSetVar {
+
+TEST_CASE("[Modules][LimboAI] BTSetVar") {
+	Ref<BTSetVar> sv = memnew(BTSetVar);
+	Ref<Blackboard> bb = memnew(Blackboard);
+	Node *dummy = memnew(Node);
+
+	sv->initialize(dummy, bb);
+
+	SUBCASE("When variable is not set") {
+		ERR_PRINT_OFF;
+		sv->set_variable("");
+		CHECK(sv->execute(0.01666) == BTTask::FAILURE);
+		ERR_PRINT_ON;
+	}
+
+	SUBCASE("With variable set") {
+		Ref<BBVariant> value = memnew(BBVariant);
+		sv->set_value(value);
+		sv->set_variable("var");
+
+		SUBCASE("When setting to a provided value") {
+			value->set_value_source(BBParam::SAVED_VALUE);
+			value->set_saved_value(123);
+			CHECK(sv->execute(0.01666) == BTTask::SUCCESS);
+			CHECK(bb->get_var("var", 0) == Variant(123));
+		}
+		SUBCASE("When assigning value of another blackboard variable") {
+			value->set_value_source(BBParam::BLACKBOARD_VAR);
+
+			SUBCASE("BB variable is empty") {
+				ERR_PRINT_OFF;
+				value->set_variable("");
+				CHECK(sv->execute(0.01666) == BTTask::FAILURE);
+				ERR_PRINT_ON;
+			}
+			SUBCASE("BB variable doesn't exist") {
+				ERR_PRINT_OFF;
+				Variant initial_value = Variant(777);
+				bb->set_var("var", initial_value);
+				value->set_variable("not_found");
+				CHECK(sv->execute(0.01666) == BTTask::FAILURE);
+				CHECK(bb->get_var("var", 0) == initial_value); // * Check initial value is intact.
+				ERR_PRINT_ON;
+			}
+			SUBCASE("BB variable exists") {
+				value->set_variable("compare_var");
+				bb->set_var("compare_var", 123);
+				CHECK(sv->execute(0.01666) == BTTask::SUCCESS);
+				CHECK(bb->get_var("var", 0) == Variant(123));
+			}
+		}
+	}
+}
+
+} //namespace TestSetVar
+
+#endif // TEST_SET_VAR_H