users 0.2.3

//! Mockable users and groups.
//!
//! When you're testing your code, you don't want to actually rely on the
//! system actually having various users and groups present - it's much better
//! to have a custom set of users that are *guaranteed* to be there, so you can
//! test against them.
//!
//! This sub-library allows you to create these custom users and groups
//! definitions, then access them using the same `Users` trait as in the main
//! library, with few changes to your code.
//!
//! Creating Mock Users
//! -------------------
//!
//! The only thing a mock users object needs to know in advance is the UID of
//! the current user. Aside from that, you can add users and groups with
//! `add_user` and `add_group` to the object:
//!
//! ```
//! use users::mock::{MockUsers, User, Group};
//! let mut users = MockUsers::with_current_uid(1000);
//! users.add_user(User { uid: 1000, name: "Bobbins".to_string(), primary_group: 100 });
//! users.add_group(Group { gid: 100, name: "funkyppl".to_string(), members: vec![ "other_person".to_string() ] });
//! ```
//!
//! The exports get re-exported into the mock module, for simpler `use` lines.
//!
//! Using Mock Users
//! ----------------
//!
//! To set your program up to use either type of Users object, make your
//! functions and structs accept a generic parameter that implements the `Users`
//! trait. Then, you can pass in an object of either OS or Mock type.
//!
//! Here's a complete example:
//!
//! ```
//! use users::{Users, OSUsers, User};
//! use users::mock::MockUsers;
//!
//! fn print_current_username<U: Users>(users: &mut U) {
//! 	println!("Current user: {:?}", users.get_current_username());
//! }
//!
//! let mut users = MockUsers::with_current_uid(1001);
//! users.add_user(User { uid: 1001, name: "fred".to_string(), primary_group: 101 });
//! print_current_username(&mut users);
//!
//! let mut actual_users = OSUsers::empty_cache();
//! print_current_username(&mut actual_users);
//! ```

pub use super::{Users, User, Group};
use std::collections::HashMap;

/// A mocking users object that you can add your own users and groups to.
pub struct MockUsers {
	users: HashMap<i32, User>,
    groups: HashMap<u32, Group>,
    uid: i32,
}

impl MockUsers {
	/// Create a new, empty mock users object.
	pub fn with_current_uid(current_uid: i32) -> MockUsers {
		MockUsers {
			users: HashMap::new(),
			groups: HashMap::new(),
			uid: current_uid,
		}
	}

	/// Add a user to the users table.
	pub fn add_user(&mut self, user: User) -> Option<User> {
		self.users.insert(user.uid, user)
	}

	/// Add a group to the groups table.
	pub fn add_group(&mut self, group: Group) -> Option<Group> {
		self.groups.insert(group.gid, group)
	}
}

impl Users for MockUsers {
    fn get_user_by_uid(&mut self, uid: i32) -> Option<User> {
    	self.users.get(&uid).cloned()
    }

    fn get_user_by_name(&mut self, username: String) -> Option<User> {
		self.users.values().find(|u| u.name == username).cloned()
    }

    fn get_group_by_gid(&mut self, gid: u32) -> Option<Group> {
    	self.groups.get(&gid).cloned()
    }

    fn get_group_by_name(&mut self, group_name: String) -> Option<Group> {
    	self.groups.values().find(|g| g.name == group_name).cloned()
    }

    fn get_current_uid(&mut self) -> i32 {
    	self.uid
    }

    fn get_current_username(&mut self) -> Option<String> {
    	self.users.get(&self.uid).map(|u| u.name.clone())
    }
}

#[cfg(test)]
mod test {
	use super::{Users, User, Group, MockUsers};

	#[test]
	fn current_username() {
		let mut users = MockUsers::with_current_uid(1337);
		users.add_user(User { uid: 1337, name: "fred".to_string(), primary_group: 101 });
		assert_eq!(Some("fred".to_string()), users.get_current_username())
	}

	#[test]
	fn no_current_username() {
		let mut users = MockUsers::with_current_uid(1337);
		assert_eq!(None, users.get_current_username())
	}

	#[test]
	fn uid() {
	    let mut users = MockUsers::with_current_uid(0);
		users.add_user(User { uid: 1337, name: "fred".to_string(), primary_group: 101 });
		assert_eq!(Some("fred".to_string()), users.get_user_by_uid(1337).map(|u| u.name))
	}

	#[test]
	fn username() {
		let mut users = MockUsers::with_current_uid(1337);
		users.add_user(User { uid: 1440, name: "fred".to_string(), primary_group: 101 });
		assert_eq!(Some(1440), users.get_user_by_name("fred".to_string()).map(|u| u.uid))
	}

	#[test]
	fn no_username() {
		let mut users = MockUsers::with_current_uid(1337);
		users.add_user(User { uid: 1440, name: "fred".to_string(), primary_group: 101 });
		assert_eq!(None, users.get_user_by_name("criminy".to_string()).map(|u| u.uid))
	}

	#[test]
	fn no_uid() {
	    let mut users = MockUsers::with_current_uid(0);
		assert_eq!(None, users.get_user_by_uid(1337).map(|u| u.name))
	}

	#[test]
	fn gid() {
	    let mut users = MockUsers::with_current_uid(0);
		users.add_group(Group { gid: 1337, name: "fred".to_string(), members: vec![], });
		assert_eq!(Some("fred".to_string()), users.get_group_by_gid(1337).map(|g| g.name))
	}

	#[test]
	fn group_name() {
	    let mut users = MockUsers::with_current_uid(0);
		users.add_group(Group { gid: 1337, name: "fred".to_string(), members: vec![], });
		assert_eq!(Some(1337), users.get_group_by_name("fred".to_string()).map(|g| g.gid))
	}

	#[test]
	fn no_group_name() {
	    let mut users = MockUsers::with_current_uid(0);
		users.add_group(Group { gid: 1337, name: "fred".to_string(), members: vec![], });
		assert_eq!(None, users.get_group_by_name("santa".to_string()).map(|g| g.gid))
	}

	#[test]
	fn no_gid() {
	    let mut users = MockUsers::with_current_uid(0);
		assert_eq!(None, users.get_group_by_gid(1337).map(|g| g.name))
	}
}