A cut down, standalone, Swift Package version of the InjectionIII application for use in the simulator or unsandboxed macOS.
Simply add this package to your project and add "Other Linker Flags" -Xlinker -interposable to the build settings of the targets of your project. When you launch your app and save a source file (somewhere in your home directory), this package attempts to find how to recompile the file from the most recent build log, creates a dynamic library and loads it, then "swizzles" the new function implementations into the app without having to restart it.
It should be fuctionally equivalent to using the app but it's rather new and there are likely to be some problems to iron out. If you encounter one, please file an issue. Consult the InjectionIII README for more details on how it can be used to inject an iOS app or even SwiftUI and how it works its magic.
For the sake of simplicy this version of injection is
missing two functionalities of the InjectionIII app:
"Unhiding" which exposes symbols of "default argument
generators" so they can be referenced when they are
injected and the handling of -filelist arguments used
when a target has more than 128 Swift source files.