Today I have released the Faux Pas public beta.
A big thanks to the people who tried it out in private beta and provided bug reports and other suggestions!
Faux Pas is a tool that inspects your Xcode project, and tries to find common errors: latent bugs, bad practices, or maintainability or style issues.
I created Faux Pas because I wanted something like it, and nothing like it existed.
Apple’s standard toolchain already contains programs that inspect (parts of) your project and warn about many different kinds of issues:
These tools are all great, but there are valid reasons why many potentially useful warnings fall outside of their purview. Faux Pas, however, doesn’t suffer from the same restrictions:
The Clang compiler and the static analyzer only look at your code, and the Xcode IDE only inspects a few other parts of your projects.
Faux Pas inspects all of these things together:
This means it can warn you about errors that span the boundaries between these different parts of the project. For example:
NSContactsUsageDescription) while using that API in the code
Tools in Apple’s standard developer toolchain are used by everyone who writes software for Apple’s platforms. Everyone. This means that these tools cannot be very opinionated, and that they have to be quite conservative in what they warn about.
Faux Pas is a third-party tool, which means it has no such restrictions. This allows for warnings related to “best practices” that many — but not necessarily all — developers agree with. If a developer disagrees with a particular “best practice,” they can easily disable the associated rule in Faux Pas, and only apply the ones that they agree with and find useful. Many rules also contain configuration options for fine-tuning their behavior to match the preferences of different development teams.
These design principles may help you understand what you can expect from this tool:
Some overlap is fine, but generally if Clang or Xcode can warn about something, Faux Pas shouldn’t warn about the same thing.
Faux Pas should be able to check unmodified Xcode projects — the user shouldn’t have to add e.g. special headers or configuration values to their project for it to work.
Having said that, these kinds of modifications may be required for optional features that could otherwise not be implemented (e.g. diagnostics suppression code annotations.)
All relevant features must be accessible from both the graphical user interface and the command-line interface.
We all love maintainable codebases and hate shipping bugs — Faux Pas can help you with these.
If you want details, you can check out the descriptions of the 111 rules it includes.
The app is free to try out for 30 days — try it on your project today!