Step 11: Add Tests

Create comprehensive tests co-located with each module:

#![allow(unused)]
fn main() {
#[cfg(test)]
mod tests {
    use super::*;

    fn test_uri() -> url::Url {
        // `deps_core::test_util::test_uri("/test/{manifest_file}")` builds the same thing
        // (and handles the Windows `C:` prefix) — prefer it over hand-rolling this helper.
        url::Url::parse("file:///test/{manifest_file}").unwrap()
    }

    #[test]
    fn test_parse_simple_dependencies() {
        let content = r#"..."#;
        let result = parse_{manifest}(content, &test_uri()).unwrap();
        assert!(!result.dependencies.is_empty());
    }

    #[test]
    fn test_position_tracking() {
        let content = r#"..."#;
        let result = parse_{manifest}(content, &test_uri()).unwrap();
        let dep = &result.dependencies[0];

        // Verify positions are correct
        assert!(dep.name_range.start.line > 0);
        assert!(dep.version_range.is_some());
    }

    #[tokio::test]
    async fn test_ecosystem_trait() {
        let cache = Arc::new(HttpCache::new());
        let ecosystem = {Ecosystem}Ecosystem::new(cache);

        assert_eq!(ecosystem.id(), "{ecosystem_id}");
        assert!(ecosystem.manifest_filenames().contains(&"{manifest_file}"));
    }
}
}