diff --git a/README.md b/README.md
index 20ab22828..3e8150f03 100644
--- a/README.md
+++ b/README.md
@@ -142,4 +142,6 @@ ws.rate_service(5)
 
 ws.count_of_ratings == 12
 ws.average_rating == 4.0
-```
\ No newline at end of file
+```
+
+### Note: Check your code using this [checklist](checklist.md) before pushing your solution.
diff --git a/checklist.md b/checklist.md
new file mode 100644
index 000000000..5598f87dc
--- /dev/null
+++ b/checklist.md
@@ -0,0 +1,80 @@
+# Check Your Code Against the Following Points
+
+## Code Style
+
+1. If you have some long math, you can split it onto additional variables, 
+or break after binary operations (not before - it cause the W504 errors)
+
+Good example:
+
+```python
+fuel_consumption = max_fuel_consumption * height_fuel_consumption_coeficient
+estimated_speed = plan_max_speed - wind_awerage_speed * wind_angle_coefisient
+estimated_time = distance_to_the_destinatoin / estimated_speed
+how_much_fuel_needed = fuel_consumption * estimated_time * overlap_coeficient
+```
+
+Good example:
+
+```python
+how_much_fuel_needed = (max_fuel_consumption
+                        * height_fuel_consumption_coeficient
+                        * distance_to_the_destinatoin
+                        / (plan_max_speed
+                           - wind_awerage_speed
+                           * wind_angle_coefisient)
+                        * overlap_coeficient)
+```
+
+Bad example:
+
+```python
+how_much_fuel_needed = max_fuel_consumption \
+                       * height_fuel_consumption_coeficient \
+                       * distance_to_the_destinatoin / (
+                               plan_max_speed 
+                               - wind_awerage_speed 
+                               * wind_angle_coefisient
+                       ) * overlap_coeficient
+```
+
+2. Use descriptive and correct variable names.
+
+Good example:
+
+```python
+def get_full_name(first_name: str, last_name: str) -> str:
+    return f"{first_name} {last_name}"
+```
+
+Bad example:
+```python
+def get_full_name(x: str, y: str) -> str:
+    return f"{x} {y}"
+```
+
+## Clean Code
+
+1. You can avoid else when have return statement.
+
+Good example:
+
+```python
+def is_adult(age: int) -> str:
+    if age >= 18:
+        return "adult"
+    return "not an adult"
+```
+
+Bad example:
+
+```python
+def is_adult(age: int) -> str:
+    if age >= 18:
+        return "adult"
+    else:
+        return "not an adult"
+```
+
+2. Add comments, prints, and functions to check your solution when you write your code. 
+Don't forget to delete them when you are ready to commit and push your code.
diff --git a/tests/test_main.py b/tests/test_main.py
index 9e8b54785..7928f9ae5 100644
--- a/tests/test_main.py
+++ b/tests/test_main.py
@@ -1,3 +1,5 @@
+from unittest.mock import patch
+
 import pytest
 
 from app.main import Car, CarWashStation
@@ -37,6 +39,12 @@ def test_car_wash_station(cars, wash_station, total_cost):
     income = wash_station.serve_cars(cars)
     assert income == total_cost, f"Income should equal to {total_cost}"
 
+def test_wash_single_car_is_called():
+    with patch.object(CarWashStation, 'wash_single_car') as mock_method:
+        CarWashStation(3, 9, 4, 11).serve_cars([Car(2, 1, "Ford")])
+        assert mock_method.called, "Expected 'wash_single_car' to have " \
+                                   "been called inside 'serve_cars' method"
+
 
 @pytest.mark.parametrize(
     "cars,wash_station,cars_clean_marks",
@@ -101,3 +109,17 @@ def test_rate_service(
         f"'count_of_ratings' should equal to {result_num_ratings}, "
         f"when initial 'count_of_ratings' was {init_num_ratings}"
     )
+
+
+def test_unnecessary_comment():
+    if os.path.exists(os.path.join(os.pardir, "app", "main.py")):
+        main_path = os.path.join(os.pardir, "app", "main.py")
+    else:
+        main_path = os.path.join("app", "main.py")
+
+    with open(main_path, "r") as main:
+        main_content = main.read()
+
+        assert (
+                "# write your code here" not in main_content
+        ), "Remove unnecessary comment"