firefox/third_party/rust/uniffi_testing

This crate contains helper code for testing bindings. Our general system is to generate bindings for the libraries from the examples and fixtures directories, then execute a script that tests the bindings.

Each bindings crate can do this in a different way, but the typical system is:

• Construct a UniFFITestHelper struct to assist the process
• Call UniFFITestHelper.create_out_dir() to create a temp directory to store testing files
• Call UniFFITestHelper.copy_cdylibs_to_out_dir() to copy the dylib artifacts for the example/fixture library to the out_dir. This is needed because the bindings code dynamically links to or loads from this library.
• Call UniFFITestHelper.get_compile_sources() to iterate over (udl_path, uniffi_config_path) pairs and generate the bindings from them. This step is specific to the bindings language, it may mean creating a .jar file, compiling a binary, or just copying script files over.
• Execute the test script and check if it succeeds. This step is also specific to the bindings language.