git-snip 0.3.0

mod branch;
mod hook;
mod input;
mod reference;
mod remote;
mod repo;

use std::env;
use std::io::BufRead;

use anyhow::{Context, Result};

use hook::{GitHook, GitHookType};

/// Install git-snip hook scripts for post-merge and post-rewrite.
pub fn install_hooks(force: bool) -> Result<()> {
    let current_dir = env::current_dir().context("Could not get current directory")?;
    let repo = repo::Repository::open(current_dir)?;

    println!("Installing git-snip hook script.");
    let h = GitHook::default();
    hook::install(repo.path(), &h, GitHookType::PostMerge, force)?;
    hook::install(repo.path(), &h, GitHookType::PostRewrite, force)?;

    Ok(())
}

/// Delete all local branches that are not in remote branches.
pub fn snip(no_confirm: bool, reader: impl BufRead) -> Result<()> {
    let current_dir = env::current_dir().context("Could not get current directory")?;
    let repo = repo::Repository::open(current_dir)?;

    snip_repo(&repo, no_confirm, reader)
}

fn snip_repo(repo: &repo::Repository, no_confirm: bool, reader: impl BufRead) -> Result<()> {
    let result = repo.orphaned_branches();

    if let Some(head) = &result.skipped_head {
        println!("Cannot delete current branch: {head}");
    }

    let mut branches_to_delete = result.branches;
    if branches_to_delete.is_empty() {
        println!("No local branches to delete.");
        return Ok(());
    }

    if !no_confirm {
        println!("Local branches to delete:");
        for branch in &branches_to_delete {
            println!("  - {branch}");
        }

        let user_input = input::prompt("Delete these branches? (y/n): ", reader);
        if user_input != "y" && user_input != "yes" {
            println!("Aborting.");
            return Ok(());
        }
    }

    for branch in &mut branches_to_delete {
        println!("Deleting branch: {branch}");
        branch.delete()?;
    }

    Ok(())
}

#[cfg(test)]
mod tests {
    use std::io::Cursor;

    use crate::test_utilities;

    use super::*;

    fn open_repo(testdir: &tempfile::TempDir) -> repo::Repository {
        repo::Repository::open(testdir.path()).unwrap()
    }

    #[test]
    fn test_snip_no_confirm() {
        // GIVEN a repo with orphaned branches and no_confirm=true
        let (testdir, repo) = test_utilities::create_mock_repo();
        let commit = test_utilities::get_latest_commit(&repo);
        repo.branch("orphan-1", &commit, false).unwrap();
        repo.branch("orphan-2", &commit, false).unwrap();

        // WHEN snip is called with no_confirm
        let result = snip_repo(&open_repo(&testdir), true, Cursor::new(""));

        // THEN it should succeed and the branches should be deleted
        assert!(result.is_ok());
        assert!(repo
            .find_branch("orphan-1", git2::BranchType::Local)
            .is_err());
        assert!(repo
            .find_branch("orphan-2", git2::BranchType::Local)
            .is_err());
    }

    #[test]
    fn test_snip_user_confirms() {
        // GIVEN a repo with orphaned branches and a reader that answers "y"
        let (testdir, repo) = test_utilities::create_mock_repo();
        let commit = test_utilities::get_latest_commit(&repo);
        repo.branch("orphan-1", &commit, false).unwrap();

        // WHEN snip is called and user confirms with "y"
        let result = snip_repo(&open_repo(&testdir), false, Cursor::new("y\n"));

        // THEN it should succeed and the branch should be deleted
        assert!(result.is_ok());
        assert!(repo
            .find_branch("orphan-1", git2::BranchType::Local)
            .is_err());
    }

    #[test]
    fn test_snip_user_declines() {
        // GIVEN a repo with orphaned branches and a reader that answers "n"
        let (testdir, repo) = test_utilities::create_mock_repo();
        let commit = test_utilities::get_latest_commit(&repo);
        repo.branch("orphan-1", &commit, false).unwrap();

        // WHEN snip is called and user declines with "n"
        let result = snip_repo(&open_repo(&testdir), false, Cursor::new("n\n"));

        // THEN it should succeed and the branch should still exist
        assert!(result.is_ok());
        assert!(repo
            .find_branch("orphan-1", git2::BranchType::Local)
            .is_ok());
    }

    #[test]
    fn test_snip_no_orphaned_branches() {
        // GIVEN a repo with no orphaned branches
        let (testdir, _repo) = test_utilities::create_mock_repo();

        // WHEN snip is called
        let result = snip_repo(&open_repo(&testdir), true, Cursor::new(""));

        // THEN it should succeed with no deletions
        assert!(result.is_ok());
    }
}

#[cfg(test)]
pub mod test_utilities {
    use git2::{Repository, RepositoryInitOptions};
    use tempfile::TempDir;

    /// Create a mock Git repository with initial commit in a temporary
    /// directory for testing.
    pub fn create_mock_repo() -> (TempDir, Repository) {
        let tempdir = TempDir::new().unwrap();
        let mut opts = RepositoryInitOptions::new();
        opts.initial_head("main");
        let repo = Repository::init_opts(tempdir.path(), &opts).unwrap();

        // Create initial commit
        {
            let mut config = repo.config().unwrap();
            config.set_str("user.name", "name").unwrap();
            config.set_str("user.email", "email").unwrap();
            let mut index = repo.index().unwrap();
            let id = index.write_tree().unwrap();

            let tree = repo.find_tree(id).unwrap();
            let sig = repo.signature().unwrap();
            repo.commit(Some("HEAD"), &sig, &sig, "initial\n\nbody", &tree, &[])
                .unwrap();
        }
        (tempdir, repo)
    }

    /// Find the latest commit in a repository.
    pub fn get_latest_commit(repo: &git2::Repository) -> git2::Commit<'_> {
        let head = repo.head().unwrap();
        let commit = head.peel_to_commit().unwrap();
        commit
    }
}