State transition testing in Testing Fundamentals - Interactive Code Practice

Practice - 5 Tasks

1fill in blank

easy

Complete the code to define a state transition function that moves from 'locked' to 'unlocked'.

Testing Fundamentals

def transition(state, event):
    if state == 'locked' and event == 'coin':
        return [1]
    return state

Drag options to blanks, or click blank then click option'

A'locked'

B'open'

C'unlocked'

D'closed'

Attempts:

3 left

💡 Hint

Common Mistakes

Returning the same state instead of changing it.

The function should return 'unlocked' when the state is 'locked' and the event is 'coin'.

2fill in blank

medium

Complete the code to check if the current state is 'unlocked' before locking it again.

Testing Fundamentals

def transition(state, event):
    if state == [1] and event == 'push':
        return 'locked'
    return state

Drag options to blanks, or click blank then click option'

A'locked'

B'open'

C'closed'

D'unlocked'

Attempts:

3 left

💡 Hint

Common Mistakes

Checking for the wrong state before locking.

The state must be 'unlocked' to transition to 'locked' when the event is 'push'.

3fill in blank

hard

Fix the error in the transition function to handle an invalid event by returning the current state.

Testing Fundamentals

def transition(state, event):
    if state == 'locked' and event == 'coin':
        return 'unlocked'
    elif state == 'unlocked' and event == 'push':
        return 'locked'
    else:
        return [1]

Drag options to blanks, or click blank then click option'

ANone

Bstate

C'invalid'

D'error'

Attempts:

3 left

💡 Hint

Common Mistakes

Returning an error string instead of the current state.

When the event is invalid, the function should return the current state unchanged.

4fill in blank

hard

Fill both blanks to complete the state transition dictionary and the function that uses it.

Testing Fundamentals

transitions = {
    'locked': {'coin': [1],
    'unlocked': {'push': [2]
}

def transition(state, event):
    return transitions.get(state, {}).get(event, state)

Drag options to blanks, or click blank then click option'

A'unlocked'

B'locked'

C'open'

D'closed'

Attempts:

3 left

💡 Hint

Common Mistakes

Swapping the states or using incorrect state names.

The dictionary maps 'locked' + 'coin' to 'unlocked' and 'unlocked' + 'push' to 'locked'.

5fill in blank

hard

Fill all three blanks to create a test case that verifies the transition from 'locked' to 'unlocked' on 'coin' event.

Testing Fundamentals

def test_locked_to_unlocked():
    initial_state = [1]
    event = [2]
    expected_state = [3]
    actual_state = transition(initial_state, event)
    assert actual_state == expected_state, f"Expected {expected_state}, got {actual_state}"

Drag options to blanks, or click blank then click option'

A'locked'

B'coin'

C'unlocked'

D'push'

Attempts:

3 left

💡 Hint

Common Mistakes

Mixing up event names or expected states.

The test sets initial state to 'locked', event to 'coin', and expects 'unlocked' after transition.