Xstream
Coding
Dojo #2
Warsaw, 29.11.2013
What is Dojo?
"Place of learning the way"
Coding Dojo
a
place to learn and have fun while programming
safe place to practice and learn by making mistakes
Short history
2004 - Paris, France
- No habit of improving skills outside of work environment
- Code used to learn new tech goes to production
- No tests for new technologies
-
Develop always using same skillset
Types of Coding Dojo
- Prepared Kata
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A presenter shows how to solve the challenge from scratch, using TDD and BabySteps.
-
Each step must make sense to everyone present for.
- People should interrupt only if they don't understand what is going on.
- Randori Kata
-
The challenge is solved by the coding pair (driver and copilot).
- Everyone present is invited to help.
- Each pair has a small (5 or 7 minutes) timebox to advance, using TDD and BabySteps.
- At the end of the timebox, the driver goes back to the audience, the copilot becomes driver and one of the audience step up to be copilot.
Objectives
- Learn by practicing,
- Fail in safe environment,
- Teach one another,
- Explain yourself to peers,
- Explore each other's solutions,
- Have fun!
Rules
- Simple design, baby steps,
- Unit tests are required,
- Switch in front of keyboard,
- Focus!
BabySteps
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Write unit test for Particular BabyStep
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Run it, it should fail
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If it is not failing - review the test it might be wrong
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Written test should generate interfaces
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Write an implementation until the test is green
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Go to the next BabyStep
Format
- Divide into groups,
- Present problem to be solved,
- Work on given task,
- Demo of each solution.
Problem
Assumptions:
- There are 5 books in same series,
- Each book costs 8 EUR,
- With each different book you get 5% discount.
Example:
Buying 4 books of which 3 are unique you get 15% discount for these books and no discount for 4th book.
Problem - TaSK
Write a piece of code to calculate price of any possible shopping basket giving as big discount as possible.
Problem - advanced example
- 2 copies of 1st book,
- 2 copies of 2nd book,
- 2 copies of 3rd book,
- 1 copy of 4th book,
- 1 copy of 5th book,
- Total amount?
- 5 * 8 * 0.75 + 3 * 8 * 0.9 = 51.60
- 4 * 8 * 0.8 + 4 * 8 * 0.8 = 51.20
Xstream Coding Dojo #2 Warsaw, 29.11.2013
