Trunk Based Development Explored

Trunk  Based  Development  Explored  

Carlos  Lopes  ThoughtWorks  

Guilherme  Lacerda  FACENSA/UniRi@er  

TargetTrust/Surya  SoBware  InnovaEon  

agenda  

the  problem  

impacts  

solu2ons!  

when  to  branch?  

the  problem  

different  streams,  same  codebase  

branches!  

Ronald  Widha  

merge  hell  

syntac2c  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    }  

 }  

seman2c  conflict  

class  BlaBlaBla  {    

 public  void  something(Bla  bla)  {  <<<<<<<  HEAD  

   bla  =  bla.plus(14);  =======  

   bla  =  bla.minus(7);  >>>>>>>  change  

   //other  stuff    }  

 }  

integra2on  conflicts  main.jsp:  <%@include  file="bla.jspf"  %>        master:  

 new-­‐file.jsp:  <%@include  file="bla.jspf"  %>        

agivenbranch:    bla.jspf  -­‐>  ble.jspf    main.jsp:  <%@include  file="ble.jspf"  %>        

the  merge  man/monkey  

promiscuous  integra2on  

Mar6n  Fowler  

$$$$  

Jon  Wolter  

regressions  

Jon  Wolter  

Jon  Wolter  

“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  abstrac6on  instead.”  

Stacy  Curl  

“feature  branching  is  a  poor  man's  modular  architecture,  instead  of  building  systems  with  the  ability  to  easy  swap  in  and  out  

features  at  run6me/deploy6me  they  couple  themselves  to  the  source  control  providing  this  mechanism  through  manual  merging”  

 Dan  Bodart  

all  right,  but  how  to  solve  this?  

branch  by    source  control?  

there’s  hope!  

approaches  

hide  new  func2onality  

abstrac2on  

Paul  Hammant  

big  bang  

Paul  Hammant  

itera2ve  

small  releasable  changes  

componen2za2on  

enable  flow  across  teams  

KEEP  IT  ALWAYS  RELEASABLE  

KEEP  IT  ALWAYS  RELEASABLE  

CONTINUOUS  INTEGRATION  

CONTINUOUS  INTEGRATION  

program  level    product  owner/champion    

knows  each  project  champion  and  how  to  reach  people  

Uncle  Bob  

when  to  branch?        large  change      spikes    new  release        

when  to  branch?        large  change      spikes    new  release        

when  to  branch?        large  change      spikes    new  release        

Paul  Hammant  

branching  vs.  freezing  

www.codingbyexample.org  

more  info  

thanks!