Crate runtime_macros

This crate offers a way to emulate the process of procedural macro expansion at run time. It is intended for use with code coverage tools like tarpaulin, which can’t measure the code coverage of anything that happens at compile time.

Currently, runtime-macros only works with functionlike! procedural macros. Custom derive may be supported in the future if there’s demand.

To use it, add a test case to your procedural macro crate that calls emulate_macro_expansion on a .rs file that calls the macro. Most likely, all the files you’ll want to use it on will be in your /tests directory. Once you’ve completed this step, any code coverage tool that works with your crate’s test cases will be able to report on how thoroughly you’ve tested the macro.

See the /examples directory in the repository for working examples.

Enums

• Error
  The error type for emulate_*_macro_expansion. If anything goes wrong during the file loading or macro expansion, this type describes it.

Functions

• emulate_attributelike_macro_expansion
  Searches the given Rust source code file for attribute-like macro calls and calls the functions that define how to expand them.
• emulate_derive_macro_expansion
  Searches the given Rust source code file for derive macro calls and calls the functions that define how to expand them.
• emulate_functionlike_macro_expansion
  Searches the given Rust source code file for function-like macro calls and calls the functions that define how to expand them.