why we need to branch

● write new code without affecting old code

● build and test new code in staging environments without affecting production

why we branch by abstraction

● to avoid porting code from one branch to the other

● to minimise merge operations performed by our SCM

we branch by abstractionnot to be changing our code

butto configure our code

when do we branch by abstraction

● we have to develop a new feature

● we have to change an existing feature

how do we branch by abstraction

feature flagged

feature flagged

NOT feature flagged

how do we test feature flags

how do we test feature flags

what happens when we release

● remove feature flag from command● remove feature flag from model● remove feature flag from the command test● remove feature flag from the model test● run the tests again to see that everything is

still working● ...and we LOST the previous

implementation!

we branch by abstractionnot to be changing our code

but notto configure our code

a possible solution: NO FLAGS!

a possible solution: CONFIGURATION

Robotlegs

Parsley

Solution Pros\Cons

Pros:● focusing only on the needed

behavior without touching the previous class

● rely on previous implementations and tests

● cleaner tests against cleaner classes

● only one place for feature flags● easy to revert/promote code

from/to release● no feature loss

Cons:● not a silver bullet for everything

for sure● any suggestion?

we branch by abstractionnot to be changing our code

butto configure our code