`ref-struct-di` is a Node.js library that provides a way to create ABI-compliant "struct" instances on top of Buffers using the ref "type" interface. It is a dependency-injected version of `ref-struct`, making it easier to use with alternatives like `ref-napi`. This library is particularly useful for developers working with C/C++ code or low-level system interactions in Node.js, as it allows for the creation and manipulation of C-style structs in a JavaScript environment.