Almost 3 years ago I started a tool to analyse dependencies of Swift projects. For bigger projects it’s essential to plan dependencies between classes and among modules beforehand. Otherwise a project’s inter-dependencies grow wild and after a while, everything depends on everything.
Why that’s bad you might ask? Because then it’s impossible to replace a class with different functionality, since too many other depend on it. And thus, it gets harder to implement new features, adapt existing features and keep the bug count low.
So that’s planning, but what get’s implemented is another story. It’s easy to forget about planned dependencies while implementing and that’s even more true when working in teams of 5, 10 or more people. That’s where tools for visualizing dependencies come into play. Every now and then, one can use these tools to check the actual inter-dependencies of a project and compare them with the planned ones.
The existing tools all have one big shortcoming: They ignore ordering structures like modules. All classes are layed out in one space, which gets confusing when visualizing projects with more several hundreds classes:
Demo from https://github.com/PrzemyslawCholewaDev/swift-dependency-visualizer
While this visualisation looks quite amazing it renders quite useless overwhelming when trying to check for unplanned dependencies. What’s more helping is a visualisation that considers modules and Xcode groups. Xcode groups can be used to organise a project’s classes in package-like structures.
Xcode project organising its classes into several nested groups
Like in the sample project above, one can see different features of the app organised in separate groups. There’s a Splash screen organised in the Splash group and an Integration group to accomodate a feature to setup smart kitchen appliances and a Network group to shelter the classes communicating to backends, etc. Inter-dependencies can be planned on these structures too. While it’s easily comprehensible why an Integration group is dependent on the Network group, the Splash group shouldn’t.
Swift dependency analysis tool showing one group, one contained file and its embedded class, enum and protocol definitions.
The above dependency tool shows dependencies between classes, enums and protocols. Furthermore, it depicts the groups and files as rectangles collapsable and expandable. When collapsed, the inter-dependencies of all contained elements to other elements outside this structure are still visible but depicted as dependency of the structuring element.
This tool is worked on by David Piper as part of his master thesis. I’m glad to be his advisor and very confident that at the end of his thesis, we’ll see a wonderful tool to supervise the dependencies of Swift projects. I’ll gladly keep you updated with more to come feature.
So stay tuned ✌️
