I have written before about junior developers and why testing, in my opinion, is the skill that they tend to lack. Fortunately, honing a junior dev’s testing savvy provides an excellent pair programming opportunity.

I also have some guidelines to help make the pairing exercise as productive as possible. Please note that these guidelines should not apply to all pairing sessions. This particular type of pairing is very much a teaching exercise, and should therefore be handled slightly differently than normal pair programming.

  1. The junior dev should drive; this ensures that the pairing session goes at a pace suitable for the person doing the most learning.

  2. The junior dev should approach the session with a blank slate. Be open to anything and everything that your senior dev has to offer. You can evaluate what you like and dislike about their approach after you have some testing experience of your own.

  3. The senior dev should eliminate any potential distractions. For me, this means that my laptop should be closed, and my phone remains at my desk.

  4. The senior dev should be ready to explain everything, but answering a question with something like, “Let’s ignore that for now” is okay. Answering, “I don’t know” is also okay; in fact, it may put the junior dev’s mind at ease. He or she may realize that they don’t have to know everything in order to write sufficient tests.

  5. The tests should be written for code that the junior developer has already implemented unless your team exclusively practices TDD or BDD. It can be overwhelming to push a new software methodology and new testing techniques on a green developer, so stick to writing the tests. TDD or BDD can be pushed later.

  6. You may find opportunities to refactor some code as you write the tests. Good! Do the refactoring, it will provide perfect insight into how to write more testable code.

  7. The tests should be approached as methodically as possible. I prefer to write tests from “outside-in” starting at the request or controller layer and working my way down to the model layer. Working “inside-out” from the models up to the controllers or request layer works, too.

  8. Give the pairing session as much time as necessary. If it means you burn an entire morning or an entire day teaching or pairing, that is perfectly fine. Learning to write complete tests is one of the most valuable lessons that a developer can learn.

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