Function build_view_chain

atomic-cli/src/commands/push/helpers.rs:62–81

Build the ancestor chain for a view, ordered root → leaf. Walks `parent_of` from the leaf upward, guarding against cycles with a visited set. A root view (no parent) yields a chain of length 1. `parent_of` is injected so the traversal is pure and unit-testable; the command wires it to `Repository::get_view_info(...).parent_name`. # Example ```rust,ignore // draft `orange` parented on `dev` → [

(
    leaf: &str,
    mut parent_of: impl FnMut(&str) -> Result<Option<String>, E>,
)

/// })?;
/// ```
pub fn build_view_chain<E>(
    leaf: &str,
    mut parent_of: impl FnMut(&str) -> Result<Option<String>, E>,
) -> Result<Vec<String>, ChainError<E>> {
    let mut chain = vec![leaf.to_string()];
    let mut visited: HashSet<String> = HashSet::new();
    visited.insert(leaf.to_string());

    let mut current = leaf.to_string();
    while let Some(parent) = parent_of(&current).map_err(ChainError::Lookup)? {
        if !visited.insert(parent.clone()) {
            return Err(ChainError::Cycle { view: parent });
        }
        chain.push(parent.clone());
        current = parent;
    }

    chain.reverse();
    Ok(chain)
}

// Sync Planning