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Intro to CS 9-10 / Week 08 / Mission Quest
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Week 08 · Test, Debug, Document

Mission Quest

Mission Quest: Family test team
// Test plans, four kinds of errors, and guides that help others fix problems
⏱ about 20 min

Mission Quest: Family Test Team

On a quiet afternoon, Comet folds a paper airplane for the greenhouse mail run. It dives straight into a basil pot.

"Bug report," Wren says, laughing. "Expected outcome: it glides. Actual outcome: basil."

Comet unfolds a wing. "Let's debug it. Change one thing at a time."

Wren starts a test log with three columns: change, throw and result.

Nova hovers at the end of the greenhouse and marks where each plane lands with a soft blue dot.

By the fifth version, the plane glides past the tomatoes. Comet cheers. "And now we write the guide, so anyone can fold it."

  1. Testing uses defined inputs and compares actual outcomes with expected outcomes.
  2. Good test inputs sit at or just beyond the minimum and maximum.
  3. There are four kinds of errors: logic, syntax, run-time and overflow.
  4. Hand tracing, test cases and extra output lines help find errors.
  5. Comments and troubleshooting guides help other people understand and fix a program.
◇ FAMILY TEST TEAM
Each player folds one paper airplane, any design.
Write the expected outcome first: how far do you think it will glide?
Throw each plane three times from the same spot and record where it lands.
Change only one thing, such as a wing fold or a small paper clip on the nose, then test again.
Keep a test log of each change and result. Stop after five versions.
Together, write a short troubleshooting guide: "If the plane dives, try this. If it turns, try that."
For a grown-up
Ask: why did we change only one thing at a time?
Ask: why write the expected outcome before the throw, not after?
Throw planes only where no one can be hit, and away from faces and pets.
QUEST CHECK
  • Read the question.
  • Tap your answer.
Why change only one thing between tests?
The plane dives on every throw. Which is the expected outcome, and which is the actual?
On paper, draw your best paper airplane from above. Label the change that helped it most.
What do you call a guide that helps others find and fix problems step by step? Type one word.
WHY THIS EXERCISEA troubleshooting guide shares your experience, so others can fix problems without you.
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