Perform Code Reviews

Contributed by: Maximiliano Contieri

Difficulty level: Intermediate

Conducting code reviews is a difficult but necessary task. Efficient code reviews keep the quality of code high, foster a collaborative development environment, and ensure that the codebase remains clean and manageable. Code reviews are also excellent checkpoints for learning, teaching, and onboarding new team members. Here are some recommendations for a good code review.

Focus on What Is Missing

Code reviews are excellent opportunities to spot incorrect and missing behavior. Junior software developers sometimes have a more limited focus—they might focus on understanding what has been done in the merge requests. More senior engineers might look for corner cases, scope boundaries and non-functional problems, performance or security concerns, future risks, etc.

Here is a small JavaScript example:

function dayName(day) {
    let name;
    switch (day) {
        case 1:
            name = 'Monday';
        case 2:
            name = 'Tuesday';
        case 3:
            name = 'Wednesday';
            break;
    }
    return name;
}

A cursory review might find a break statement missing after cases 1 and 2. A more detailed review will also identify there are no controls on the day boundaries and the absence of a default: switch statement. Focusing on corner cases during code reviews prevents defects from getting to production code.

Validate the Code Coverage

Most companies rely on adding coverage and usage scenarios together with modified code in an atomic way. A code review ...