wtf is swiftcov?

SwiftCov is a tool that tells you which parts of your Swift code are actually being tested. When you write tests for an app or a framework, you want to know if those tests are touching every line of your code or if there are gaps. This tool runs your existing tests and generates a report showing exactly which lines of code were executed and which were skipped, so you can see where your test coverage is missing. At a high level, it works by attaching a debugger to your test run. It places invisible markers on every line of your source code, then runs your tests while counting how many times each marker gets hit. After the tests finish, it turns that hit-count data into standard coverage files that you can view or upload to popular coverage tracking services. There is an optional threshold setting to limit how many hits it records per line, which exists purely for speed, counting every single hit on a frequently executed loop can slow things down considerably. This would be used by Swift developers and teams building iOS or OS X frameworks who want measurable proof that their tests are thorough. For example, if you have a framework that handles financial calculations, you could run this tool to confirm that your tests actually exercise the branch of code that handles a specific error case, rather than silently skipping it. One important thing to note: this project is explicitly marked as obsolete. Since Swift 2, Apple has built native code coverage support directly into the language and Xcode, so this tool is no longer maintained. It also comes with notable limitations, it only works for framework projects (not standalone apps), only runs on the simulator or OS X (not physical iOS devices), and only integrates with certain continuous integration services. It is mostly of historical interest now.