fn source_matches()

in guppy/src/graph/summaries/package_set.rs [730:784]
52 lines of code
2 McCabe index (conditional complexity)

    fn source_matches(
        package_source: PackageSource<'_>,
        third_party_source: &ThirdPartySource,
        registry_names_to_urls: &HashMap<&'a str, &'a str>,
    ) -> bool {
        match (package_source, third_party_source) {
            (PackageSource::Workspace(_), _) => {
                // third-party sources can't match a workspace package
                false
            }
            (PackageSource::Path(package_path), ThirdPartySource::Path(summary_path)) => {
                package_path == summary_path
            }
            (PackageSource::Path(_), _) => false,
            (PackageSource::External(external), ThirdPartySource::Url(summary_url)) => {
                external == summary_url
            }
            (external, _) => {
                let external_source = match external.parse_external() {
                    Some(external_source) => external_source,
                    None => {
                        // The only way this can match is with the ThirdPartySource::Url constraint
                        // above.
                        return false;
                    }
                };

                match (external_source, third_party_source) {
                    (
                        ExternalSource::Registry(external_registry_url),
                        ThirdPartySource::Registry(Some(summary_registry_name)),
                    ) => {
                        let &url = registry_names_to_urls
                            .get(summary_registry_name.as_str())
                            .expect("all names were already obtained in new()");
                        url == external_registry_url
                    }
                    (
                        ExternalSource::Registry(external_registry),
                        ThirdPartySource::Registry(None),
                    ) => external_registry == ExternalSource::CRATES_IO_URL,
                    (
                        ExternalSource::Git {
                            repository, req, ..
                        },
                        ThirdPartySource::Git {
                            repo: summary_repo,
                            req: summary_req,
                        },
                    ) => repository == summary_repo && summary_req.as_git_req() == req,
                    _ => false,
                }
            }
        }
    }