Is static type checking worth it?: On the pros and cons of adding a static type checker to an existing codebase
Rinta-Filppula, Jaakko (2021)
2021
Tietotekniikan DI-ohjelma - Master's Programme in Information Technology
Informaatioteknologian ja viestinnän tiedekunta - Faculty of Information Technology and Communication Sciences
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Hyväksymispäivämäärä
2021-05-18
Julkaisun pysyvä osoite on
https://urn.fi/URN:NBN:fi:tuni-202104263602
https://urn.fi/URN:NBN:fi:tuni-202104263602
Tiivistelmä
Even though type systems are a well-researched topic in theoretical computer science, there are relatively few studies on the differences between static and dynamic type checking for software development. There are controlled studies that focus on specific aspects of the development such as speed and code maintainability but due to their nature, these studies consider rather small codebases. This thesis augments the results of the previous research by gathering real-world data on the experiences of using static type checkers designed for dynamically typed languages.
The goal of the thesis is to find out if any benefits are observed by using these static type checking tools and whether those benefits justify any possible drawbacks. To answer these questions, an online survey was conducted to gather the experiences of a total of 138 other developers. In addition to the online survey, the author performed an experiment where he adopted Sorbet, a static type checker for Ruby, in a large codebase (approximately 80,000 lines of code) that multiple developers are working on simultaneously.
In the survey, almost everyone who had used these tools told that the tools are at least somewhat beneficial. A majority of them said that using a static type checker is very beneficial. Using a static type checker was found to improve all of the different areas of development that were asked about in the survey: code reliability, development speed, API usability, maintainability, working with unfamiliar parts of the code, and confidence in refactoring and writing new code. Overall the responses were very positive with only a small amount of negative answers.
In the exploratory experiment performed by the author the results were also positive. Even though there were problems that prevented the author from using the full potential of the type checker, undiscovered problems in the codebase were surfaced. The process of setting up and working with the tools was pleasant. All in all, it seems that using these kinds of static type checkers in dynamically typed languages can provide significant benefits and improve the software development process.
The goal of the thesis is to find out if any benefits are observed by using these static type checking tools and whether those benefits justify any possible drawbacks. To answer these questions, an online survey was conducted to gather the experiences of a total of 138 other developers. In addition to the online survey, the author performed an experiment where he adopted Sorbet, a static type checker for Ruby, in a large codebase (approximately 80,000 lines of code) that multiple developers are working on simultaneously.
In the survey, almost everyone who had used these tools told that the tools are at least somewhat beneficial. A majority of them said that using a static type checker is very beneficial. Using a static type checker was found to improve all of the different areas of development that were asked about in the survey: code reliability, development speed, API usability, maintainability, working with unfamiliar parts of the code, and confidence in refactoring and writing new code. Overall the responses were very positive with only a small amount of negative answers.
In the exploratory experiment performed by the author the results were also positive. Even though there were problems that prevented the author from using the full potential of the type checker, undiscovered problems in the codebase were surfaced. The process of setting up and working with the tools was pleasant. All in all, it seems that using these kinds of static type checkers in dynamically typed languages can provide significant benefits and improve the software development process.