The long way through Software Craftsmanship

Open discussion: On code reviews

Feb 7, 2015 - 3 minute read - Comments - internal-trainingopen-discussioncode-reviewpair-programmingtraining

At a client, I organized an open discussion on code reviews. We had a great conversation.

The main idea was to discuss about it and share the ideas each one had. I didn’t want it to turn into a masterclass (see the white belt)


These are the main benefits we saw in it:

  • Increased trust
  • Learning from others, other approaches
  • Less defects, more quality
  • Increased bus factor, decreased information silos
  • Also:
    • Getting out of your comfort zone
    • Communicating more often (code style, edge cases, complaining, etc)

Pair programming

Then we discussed about the topic of code reviews and pair programming:

  • How do they mix

    • Is the need for code review reduced when doing pair programming?
    • It is cheaper to catch defects when pairing than code review (e.g., less to modify, mental caches are hot, …), so why do code reviews? J. B. Rainsberger has an article about it
  • Does it give you the same benefits?

    • I argued that it does, some of my colleagues argued against as one is “while doing” and the other is after.

Practice, Practice, Practice

This is also a reference to a chapter by the same name (here)

We proposed this problem:

Receive a list of numbers to a command-line (CLI) application and print their sum

I wrote simple code listing and we reviewed it. The code is here as a gist

(Just in case, I wrote this listing with some defects / smells on purpose)

Here are the comments:

  • Not all parameters will be added, only the first three
  • The parameters are out of order, overcomplicating things. Is it due to something? Should I be careful about it?
  • There is duplication (i.e., parsing from string)
  • Bad naming: what is a, b, c?
  • There are no tests for it. No manual / javadoc either. Therefore, it’s difficult to maintain
  • Difficult to test: a smell for bad design?

    • How to test the adding by itself? The output is to the console, so we have to capture it (at GMaur we published this tool: legacyUtils)
    • How to test the parsing if there is no mock to be injected? Only via state tests, therefore “end to end” tests as it includes the adding
  • Mixed concerns / responsibilities. Parsing the numbers and adding them are different concerns and should not be together


  • No one was against it
  • We all agreed that is important to do it even in time-constrained environments
  • It is also important to review our code reviews to make the most of it. The article by J. B. Rainsberger is quite useful for that
  • Even small codes can be bad and need to be reviewed (as the example)
  • Quick and dirty proof of concept do not mix well with code reviews

Pairing with junior developers Implementing BDD at a client

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