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Bray
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one or more tests failed
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all tests passed
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syntax error
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team
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review dashboard
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oldest newest summaries
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1 minute
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diff
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cyber-dojo.org has ~ 30,000 cyber-dojos
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…some data… from a random
sample of 500
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colour-to-colour diff deltas3.94
5.39
4.67
4.65
7.52
6.01
17.67
average lines of code added+deleted
13.65
bigger delta ==
greater chance of amber
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bigger delta ==
greater chance of amber
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11
5 6
lots of amber runs
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colour-to-colour percentages
7.0%
7.8%
8.0%
8.1%
8.4%
11.1%
11.2%
11.3%
27.1%
lots of amber
to amber
for example
45 minute exercise
code
test?
FizzBuzz
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waterfail
45 minute exercise
test
9 month project
waterfail
test
8 months 1 month
waterfail
test
> 8 months < 1 month
waterfail
waterfailtesttest testtest test testtest test testtest test testtest test testtest test test
testtesttesttest
debugging!
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debugging ==
removing what you don't want
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suppose you manage to remove
what you don't want
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will you be left with what you do want?
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it’s like making toast by burning bread and then scraping
the burn off!
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specifying
debugging
DDD
TDD
specifying specifications specifications
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tests
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specifications
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specific?
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!
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specific
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suppose you’ve measured the complexity of
your code and tests
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larger number ==
more complexity
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2.1
the average complexity of the code is
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by the way…
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did you hear the one about the statistician who drowned
crossing a river only six inches deep*
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did you hear the one about the statistician who drowned
crossing a river only six inches deep*
*average depth!
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3.7
the average complexity of the tests is
tests
3.7 2.1
code
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tests tests
11.2
tests
3.7 2.1
code
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tests tests
11.2
tests
3.7 2.1
codeNO!
tests
2.0 2.1
code
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<
< is the less than operator
tests
1.6 2.1
code
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<<
<< is the much less than operator
tests
1.0 2.1
code
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YES<<<
<<< is the much much less than operator
tests
1.0 2.1
code
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teststeststestsYES<<<
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example
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example
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red green
refactor
refactor
write a test for new functionality
implement the new functionality
refactor
write a test for new functionality
implement the new functionality
refactor
write a test for new functionality
implement the new functionality
improve the diagnostic
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diagnostics that
diagnose!
refactor
write a test for new functionality
implement the new functionality
improve the diagnostic
coding
testing
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Test Driven
Development
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why do cars have brakes?
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so you can drive faster
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feedback
test test test test test
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just calling it feedback doesn’t mean it has actually fed back!
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101
sensespancreas
senses
liver &muscles
causes glycogen
causes
Hyperglycemia
pancreas
senses
glucagoncauses
sensescauses
insulin
causes
Hypoglycemia
causes
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all change can be understood as the effort to maintain some constancy, and all constancy as maintained through change
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Henri Louis Le Chatelier
systems tend to oppose their own
proper function
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coding
testing
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the battle is a means or process
of generating, maintaining, and
stabilising a system
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evolution is always
co-evolution
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a co-evolving system
coding
testing
