In main.rs, add a unit test for the cargo_dir function that checks that it returns the correct source code directory for a crate that is a dependency of a crate that is a top-level dependency.
For example, clap is one of this project's top-level dependencies, and ansi_term is one of clap's dependencies. So if we run cargo_dir("ansi_term") in the context of this project, we should get the correct source code directory for ansi_term even though it's not in the Cargo.toml file directly.
In
main.rs, add a unit test for thecargo_dirfunction that checks that it returns the correct source code directory for a crate that is a dependency of a crate that is a top-level dependency.For example,
clapis one of this project's top-level dependencies, andansi_termis one ofclap's dependencies. So if we runcargo_dir("ansi_term")in the context of this project, we should get the correct source code directory foransi_termeven though it's not in theCargo.tomlfile directly.