closure-tree (Rust)

A SeaORM-friendly port of Ruby's closure_tree.

Status

Early preview (0.0.1). PostgreSQL only. Contributions welcome.

Quickstart

[dependencies]
closure-tree = "0.0.1"

use closure_tree::ClosureTreeRepository;
use closure_tree::ClosureTreeModelDerive as ClosureTreeModel;
use sea_orm::entity::prelude::*;

#[derive(Clone, Debug, PartialEq, DeriveEntityModel, ClosureTreeModel)]
#[sea_orm(table_name = "nodes")]
#[closure_tree(hierarchy_module = "crate::entity::node_hierarchy", hierarchy_table = "node_hierarchies")]
pub struct Model {
    #[sea_orm(primary_key)]
    pub id: i32,
    pub parent_id: Option<i32>,
    pub name: String,
}

#[tokio::main]
async fn main() -> Result<(), Box<dyn std::error::Error>> {
    let db = sea_orm::Database::connect("postgres://...").await?;
    let repo = ClosureTreeRepository::<entity::node::Model>::new();

    let _leaf = repo
        .find_or_create_by_path(&db, &["root", "child", "leaf"])
        .await?;

    Ok(())
}

Features

• Derive macro for SeaORM models (#[derive(ClosureTreeModel)]).
• Repository helpers (parent, descendants, find_by_path, find_or_create_by_path, etc.).
• Advisory locks via pg_advisory_lock, rebuild utilities.
• Integration test against a Docker Postgres instance.

Limitations

• PostgreSQL only.
• Ordering, hash_tree, dependent strategies, and some Ruby APIs are not yet ported.
• Advisory lock is limited to Postgres advisory locks; no MySQL adapter yet.

Development

cargo fmt
cargo clippy --all-targets -- -D warnings
cargo test

Requires Docker Postgres at postgres://closure_tree:closure_tree_pass@localhost:5434/closure_tree_test (see tests/postgres.rs).