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Why Do Developers Use Trivial Packages?

Reviewed by Greg Wilson / 2021-09-17
Keywords: Packaging

"Reduce, re-use, recycle" is probably the most useful advice someone can give a young programmer, but is it possible to take re-use too far? In particular, is it worth creating and sharing a library that contains only one small function? Conversely, is it sensible to use such micro-libraries?

To find out, the authors of Abdalkareem2017 looked at 230,000 NPM packages and 38,000 JavaScript applications. At the time (four years ago) 16.8% of the packages used were trivial, which they defined as having no more than 35 lines of code and a McCabe complexity score no greater than 10. (See this review and Herraiz2010 for discussion of why measuring complexity was probably redundant.) Almost 11% of applications used trivial packages, and 58% of developers thought this was a good practice: in general, they thought these packages were well implemented and well tested, and that using them would increase productivity.

Developers only major concern with using trivial packages was the dependency overhead. However, the authors found that, "Contrary to developers' perception, only 45.2% of trivial packages actually have tests." Instead, their reliability comes from being "deployment tested", i.e., so many people use them that meaningful edge cases are found and fixed relatively quickly.

So should developers use trivial packages or not? I think that framing misses the point. Developers do use trivial packages; telling them not to is as vacuous as saying that abstinence will solve the problem of teenage pregnancy. What researchers can and should do is identify situations where using those packages is sensible and help people do it better and more safely. It would be fascinating to see this work repeated for other languages, particularly ones like Python that are primarily used for server-side work.

Abdalkareem2017 Rabe Abdalkareem, Olivier Nourry, Sultan Wehaibi, Suhaib Mujahid, and Emad Shihab: "Why do developers use trivial packages? An empirical case study on NPM". Proceedings of the 2017 11th Joint Meeting on Foundations of Software Engineering, 10.1145/3106237.3106267.

Code reuse is traditionally seen as good practice. Recent trends have pushed the concept of code reuse to an extreme, by using packages that implement simple and trivial tasks, which we call 'trivial packages'. A recent incident where a trivial package led to the breakdown of some of the most popular web applications such as Facebook and Netflix made it imperative to question the growing use of trivial packages. Therefore, in this paper, we mine more than 230,000 npm packages and 38,000 JavaScript applications in order to study the prevalence of trivial packages. We found that trivial packages are common and are increasing in popularity, making up 16.8% of the studied npm packages. We performed a survey with 88 Node.js developers who use trivial packages to understand the reasons and drawbacks of their use. Our survey revealed that trivial packages are used because they are perceived to be well implemented and tested pieces of code. However, developers are concerned about maintaining and the risks of breakages due to the extra dependencies trivial packages introduce. To objectively verify the survey results, we empirically validate the most cited reason and drawback and find that, contrary to developers' beliefs, only 45.2% of trivial packages even have tests. However, trivial packages appear to be `deployment tested' and to have similar test, usage and community interest as non-trivial packages. On the other hand, we found that 11.5% of the studied trivial packages have more than 20 dependencies. Hence, developers should be careful about which trivial packages they decide to use.