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Code review of randomness


Last week, prior to a weekly meeting, one of my team members had the idea to take a few minutes before the meeting to review some code. We already do code reviews prior to deployments, but we've been wanting to improve the quality of the code reviews... we wanted to really have good dialog about code quality and be able to share that discussion with the whole team.

Code reviews... but random

So we were all on board with a more fully featured code review... but whose code would we choose? We weren't exactly getting volunteers left and right to offer up their code... probably because they knew that everyone else would find some reason to skewer it. After all, no code is perfect... there is almost always room for improvement.

Another problem with volunteered code is that it would typically be code that had been seen recently. New code tends to be of higher quality than legacy code; however, we have plenty of legacy code that could be greatly improved by having the team take just 10 minutes to look over it.

The solution was a PowerShell script that I whipped together in about 15 minutes. Here it is:

param (
    $fileType = "cs",
    $directoryToSearch = "c:\path\to\source\repo"

$scriptDir = (Split-Path $MyInvocation.MyCommand.Path -Parent)
$editor = 'C:\Program Files\Sublime Text 2\sublime_text.exe'

$excludedFilePaths =

function notIn($lookFor, $toSearch) {
    foreach ($toExclude in $toSearch) {
        if ($lookFor -match $toExclude) {
            return $false
    return $true

function allFilesOfType {
    ls -filter "*.$fileType" -recurse |
        where { notIn $_.FullName $excludedFilePaths }

Push-Location $directoryToSearch

"Drum roll, please..."

$randomlySelectedFile  = allFilesOfType | Get-Random -count 1 | select -expand FullName
& $editor $randomlySelectedFile


As you can see, it is pretty basic. Most of the complexity involves excluding Designer or generated files. Once the script determines a random file, it opens it in a text editor for the team to view. From there, we began looking at it as a team and calling out issues... "we should use var here," "can we rename that variable?," "I think we need to dispose of that object," etc. In a short 15 minutes, we as a team were able to find all sorts of minor issues with the code.

Team Learning, Team Dialog, and Decreasing Technical Debt

By reviewing the code together, it allowed us to share the learning about what we as a team thought made for quality code. Often while pair programming, these discussions come up, but they were only between 2 or 3 at most... by doing this together, we could all benefit from the discussion.

Another benefit is that it forces us to become familiar with random parts of our system. I'm confident that almost every development team has some aspect of the "Train (or bus) Problem" as I call it... if someone on your team were hit by a train (or bus), could the rest of the team pick up without them? If not, then there is a potential liability there. By reviewing code as a group, the team can become familiar with the code together.

From a technical debt perspective, we now have another tool in our arsenal that we can use to slowly improve code. Ideally, if we continue improving our core code in this way, in six months or so we'll have trouble finding issues. We might have to go after specific sections of our code to review at that point. Either way, we've got something started that seems to be very beneficial.

Leave a comment if your team does something similar.