Coding Problems: One Less Exception

In this article:
Subscribe to our blog:

java.util.NoSuchElementException: No value found for ‘USD’
at scala.Enumeration.withName(Enumeration.scala:124)

Dammit! I hate it when code blows in production.
For some cases there’s just no tests or static analysis that can cover you.

This is one of those cases. Calling the withName method with an inexistent value in an Enumeration will blow up. Sure, it throws an Exception, but since Scala has unchecked exceptions, the compiler won’t warn you.

https://gist.github.com/mrfyda/ad94180cd00613cf314b

Unfortunately, it wasn’t the first time we had exactly this problem, so we agreed to start avoiding the withName method and writing it as:

https://gist.github.com/mrfyda/d9241e947c1600866069

Since find returns an Option, the code needs to be ready to deal with the possibility of a non existing value.

We also want all of our users to stay safe, so today we’re adding a new code pattern: Prohibit withName on Enumeration.
You can check your code for this issue and fix it before it blows in production!


Edit: We just published an ebook: “The Ultimate Guide to Code Review” based on a survey of 680+ developers. Enjoy!


About Codacy

Codacy is used by thousands of developers to analyze billions of lines of code every day!

Getting started is easy – and free! Just use your  GitHub, Bitbucket or Google account to sign up.

GET STARTED

RELATED
BLOG POSTS

Open source projects: merging schedules
When do open source projects merge their pull requests? I was curious about the merging time patterns of pull requests from open source projects. So I...
Automatic comments on your pull requests: new Codacy feature
Automatic comments on your pull requests with our code analysis results is a new feature we have launched after beta tests with users.
Visualizing pull request lifespan vs programming languages
The way pull requests are made, closed and merged has been intriguing me for a while. Pull requests have slowly become the standard flow of operations...

Automate code
reviews on your commits and pull request

Group 13