add

Author: benpaddlejones

tutorials/Lecture8.md

@@ -0,0 +1,141 @@
+# Lecture 8
+
+## Lecture 7 concepts
+
+- [What Are Stubs and Drivers?](#what-are-stubs-and-drivers)
+- [Why Use Stubs and Drivers?](#why-use-stubs-and-drivers)
+- [Simple Example](#simple-example)
+  - [Stub Example](#stub-example)
+  - [Driver Example](#driver-example)
+- [How to Use Them Together](#how-to-use-them-together)
+
+## What Are Stubs and Drivers? 
+
+Imagine you're building a puzzle:
+- A **stub** is a fake puzzle piece you use temporarily
+- A **driver** is a simple tool to check if your real pieces fit together
+
+Definitions
+A **stub** is a simplified version that replaces a real lower component so it doesn't need to be full implemented.
+A **driver** is a simple program in a higher system that tests a lower component without fully implementing the higher system.
+
+## Why Use Stubs and Drivers?
+
+1. **Test in parts**: Check each piece of your code separately
+2. **No dependencies**: Test without needing everything to be finished
+3. **Controlled testing**: Create specific test scenarios easily
+4. **Faster development**: Don't need to wait for other parts to be done
+
+This simple approach helps you build and test your code without needing to complete your system!
+
+## Simple Example
+
+Let's say we have a simple traffic light system:
+
+```python
+# traffic_light.py
+class TrafficLight:
+    def __init__(self):
+        self.color = "red"
+    
+    def change_color(self):
+        if self.color == "red":
+            self.color = "green"
+        elif self.color == "green":
+            self.color = "yellow"
+        else:
+            self.color = "red"
+    
+    def get_color(self):
+        return self.color
+```
+
+### Stub Example
+
+Remember a **stub** is a simplified version that replaces a real lower component so it doesn't need to be full implemented.
+
+```python
+# traffic_light_stub.py
+class TrafficLightStub:
+    def __init__(self):
+        self.color = "red"
+    
+    def change_color(self):
+        # Just pretend to change color - always return green for testing
+        self.color = "green"
+    
+    def get_color(self):
+        return self.color
+```
+
+### Driver Example
+
+Remember a **driver** is a simple program in a higher system that tests a lower component without fully implementing the higher system.
+
+```python
+# traffic_light_driver.py
+
+# Import the real component we want to test
+from traffic_light import TrafficLight
+
+def test_traffic_light():
+    print("Testing Traffic Light...")
+    
+    # Create the traffic light
+    light = TrafficLight()
+    
+    # Test initial state
+    print(f"Initial color: {light.get_color()}")
+    
+    # Test color change
+    light.change_color()
+    print(f"After first change: {light.get_color()}")
+    
+    light.change_color()
+    print(f"After second change: {light.get_color()}")
+    
+    light.change_color()
+    print(f"After third change: {light.get_color()}")
+    
+    print("Test complete!")
+
+# Run the test
+test_traffic_light()
+```
+
+## How to Use Them Together
+
+You can use the stub to test other parts of your system:
+
+```python
+# car_driver.py
+from traffic_light_stub import TrafficLightStub
+
+def test_car_behavior():
+    print("Testing car behavior at traffic light...")
+    
+    # Create the stub traffic light
+    light = TrafficLightStub()
+    
+    # Test car behavior
+    print(f"Light is {light.get_color()}")
+    
+    if light.get_color() == "red":
+        print("Car stops")
+    else:
+        print("Car drives")
+    
+    # Change the light
+    light.change_color()
+    print(f"Light changed to {light.get_color()}")
+    
+    if light.get_color() == "red":
+        print("Car stops")
+    else:
+        print("Car drives")
+    
+    print("Test complete!")
+
+# Run the test
+test_car_behavior()
+```