When To Code Review Changes Versus the Whole File


Reading through some old documentation today written up a few years ago by our Agile coach I came across a suggested rule of thumb for code reviews:

  • If more than X lines of code changed in a file then do a full code review of the file.
  • If less than X lines of code changed you can just review the diffs.
  • Developers should decide on where to set the bar for lines of code.

Strikes me as a pretty reasonable option. We’ve been reviewing whole classes except in a few circumstances, but we never set a rule on how many lines of code make it worth doing a full review. Maybe 20 lines is a good number.