Function validate_crate_contents 

pub fn validate_crate_contents(
    reader: impl Read,
    expected_crate_name: &str,
    expected_files: &[&str],
    expected_contents: impl Into<InMemoryDir>,
)

Checks the contents of a .crate file.

• expected_crate_name should be something like foo-0.0.1.crate.
• expected_files should be a complete list of files in the crate (relative to expected_crate_name).
• expected_contents should be a list of (file_name, contents) tuples to validate the contents of the given file. Only the listed files will be checked (others will be ignored).