multiple projects, different goals, one thing in common: the codebase!
DESCRIPTION
Trunk-based development talk given at Agile India 2014 in Bangalore.TRANSCRIPT
Multiple projects, different goals, one thing in
common: the codebase!
Carlos Lopes@carlosaml
why?
blog.crisp.se
Jon Wolter
ok
a little story
an online store(of whatever)
10
11
12
13
14
15
16
17
18
19
21
22
23
24
what’s next?
26
27
28
29
30
now what?
32
34
HOWEVER
38
43
merge hell
45
a LOT going on for at least months...
46
47
big scary merge before a big scary release
syntactic conflict
class BlaBlaBla {
<<<<<<< HEAD! public void bla(Bla oldBla, New newBla) {! ! oldBla.bla();! ! newBla.newBla();=======! public void bla(Bla oldBla, Other otherBla) {! ! oldBla.bla();! ! otherBla.otherBla();>>>>>>> other commit! }
}
semantic conflict
class BlaBlaBla {
! public void something(Bla bla) {<<<<<<< HEAD! ! bla = bla.plus(14);=======! ! bla = bla.minus(7);>>>>>>> change! ! //other stuff! }
}
integration conflicts
main.jsp: <%@include file="hello.jspf" %>
trunk:
new-file.jsp:
<%@include file="hello.jspf" %>
agivenbranch:
hello.jspf => hey.jspf
main.jsp:
<%@include file="hey.jspf" %>
and so forth
regressions
however...
the loyalty program team learnt something...
merge monkey
59
60
continuous integration?
62
63
how many pipelines for this?
and how effective would they even be?
65
66still need to “integrate”
67
big scary merge
promiscuous integration
martinfowler.com/bliki/FeatureBranch.html
69
how about refactoring?
undeployable code
72
only trunk was releasableat any given time
$$$$$
ok, so what do we do?
“Feature branching is a poor man's modular architecture, instead of
building systems with the ability to easy swap in and out features at runtime/deploytime they couple themselves to
the source control providing this mechanism through manual merging.”
Dan Bodart
“The bigger the apparent reason to branch, the more you
shouldn’t branch.”
Jez Humble / David Farley
“Don't separate differing concerns by using a VCS, use an
abstraction instead.”
Stacy Curl
solutions?
branch bysource controlabstraction
paulhammant.com/blog/branch_by_abstraction.html
trunk-based development
trunk-based development
shopping cart?
trunk-based development
shopping cart?
loyalty program?
if (myFeatureIsOn) {doSomething();}
martinfowler.com/bliki/FeatureToggle.html
featuretoggles/flags/bits
martinfowler.com/bliki/BranchByAbstraction.html
Paul Hammant
iterative
Paul Hammant
big bang
enables refactoringgowebbaby.com/magento-responsive-design/
91
93
always releasable
95
testcoverage
branching patterns
98
99
100
101
102
paulhammant.com/2013/03/13/facebook-tbd-take-2/
“Feature branching is a poor man's modular architecture, instead of
building systems with the ability to easy swap in and out features at runtime/deploytime they couple themselves to
the source control providing this mechanism through manual merging.”
Dan Bodart
questions?