tests.rs

		.balance_factor(100)
		.min_nominator_bond(1_000)
		.min_validator_bond(1_500)
		.build_and_execute(|| {
			let initial_validators = CounterForValidators::<Test>::get();
			let initial_nominators = CounterForNominators::<Test>::get();
			for i in 0..15 {
				let a = 4 * i;
				let b = 4 * i + 1;
				let c = 4 * i + 2;
				let d = 4 * i + 3;
				Balances::make_free_balance_be(&a, 100_000);
				Balances::make_free_balance_be(&b, 100_000);
				Balances::make_free_balance_be(&c, 100_000);
				Balances::make_free_balance_be(&d, 100_000);

				// Nominator
				assert_ok!(Staking::bond(
					Origin::signed(a),
					b,
					1000,
					RewardDestination::Controller
				));
				assert_ok!(Staking::nominate(Origin::signed(b), vec![1]));

				// Validator
				assert_ok!(Staking::bond(
					Origin::signed(c),
					d,
					1500,
					RewardDestination::Controller
				));
				assert_ok!(Staking::validate(Origin::signed(d), ValidatorPrefs::default()));
			}

			// To chill other users, we need to:
			// * Set a minimum bond amount
			// * Set a limit
			// * Set a threshold
			//
			// If any of these are missing, we do not have enough information to allow the
			// `chill_other` to succeed from one user to another.

			// Can't chill these users
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 1),
				Error::<Test>::CannotChillOther
			);
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 3),
				Error::<Test>::CannotChillOther
			);

			// Change the minimum bond... but no limits.
			assert_ok!(Staking::set_staking_limits(Origin::root(), 1_500, 2_000, None, None, None));

			// Still can't chill these users
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 1),
				Error::<Test>::CannotChillOther
			);
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 3),
				Error::<Test>::CannotChillOther
			);

			// Add limits, but no threshold
			assert_ok!(Staking::set_staking_limits(
				Origin::root(),
				1_500,
				2_000,
				Some(10),
				Some(10),
				None
			));

			// Still can't chill these users
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 1),
				Error::<Test>::CannotChillOther
			);
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 3),
				Error::<Test>::CannotChillOther
			);

			// Add threshold, but no limits
			assert_ok!(Staking::set_staking_limits(
				Origin::root(),
				1_500,
				2_000,
				None,
				None,
				Some(Percent::from_percent(0))
			));

			// Still can't chill these users
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 1),
				Error::<Test>::CannotChillOther
			);
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 3),
				Error::<Test>::CannotChillOther
			);

			// Add threshold and limits
			assert_ok!(Staking::set_staking_limits(
				Origin::root(),
				1_500,
				2_000,
				Some(10),
				Some(10),
				Some(Percent::from_percent(75))
			));

			// 16 people total because tests start with 2 active one
			assert_eq!(CounterForNominators::<Test>::get(), 15 + initial_nominators);
			assert_eq!(CounterForValidators::<Test>::get(), 15 + initial_validators);

			// Users can now be chilled down to 7 people, so we try to remove 9 of them (starting with 16)
			for i in 6..15 {
				let b = 4 * i + 1;
				let d = 4 * i + 3;
				assert_ok!(Staking::chill_other(Origin::signed(1337), b));
				assert_ok!(Staking::chill_other(Origin::signed(1337), d));
			}

			// chill a nominator. Limit is not reached, not chill-able
			assert_eq!(CounterForNominators::<Test>::get(), 7);
			assert_noop!(
				Staking::chill_other(Origin::signed(1337), 1),
				Error::<Test>::CannotChillOther
			);
			// chill a validator. Limit is reached, chill-able.
			assert_eq!(CounterForValidators::<Test>::get(), 9);
			assert_ok!(Staking::chill_other(Origin::signed(1337), 3));
		})
}

#[test]
fn capped_stakers_works() {
	ExtBuilder::default().build_and_execute(|| {
		let validator_count = CounterForValidators::<Test>::get();
		assert_eq!(validator_count, 3);
		let nominator_count = CounterForNominators::<Test>::get();
		assert_eq!(nominator_count, 1);

		// Change the maximums
		let max = 10;
		assert_ok!(Staking::set_staking_limits(
			Origin::root(),
			10,
			10,
			Some(max),
			Some(max),
			Some(Percent::from_percent(0))
		));

		// can create `max - validator_count` validators
		let mut some_existing_validator = AccountId::default();
		for i in 0..max - validator_count {
			let (_, controller) = testing_utils::create_stash_controller::<Test>(
				i + 10_000_000,
				100,
				RewardDestination::Controller,
			)
			.unwrap();
			assert_ok!(Staking::validate(Origin::signed(controller), ValidatorPrefs::default()));
			some_existing_validator = controller;
		}

		// but no more
		let (_, last_validator) = testing_utils::create_stash_controller::<Test>(
			1337,
			100,
			RewardDestination::Controller,
		)
		.unwrap();

		assert_noop!(
			Staking::validate(Origin::signed(last_validator), ValidatorPrefs::default()),
			Error::<Test>::TooManyValidators,
		);

		// same with nominators
		let mut some_existing_nominator = AccountId::default();
		for i in 0..max - nominator_count {
			let (_, controller) = testing_utils::create_stash_controller::<Test>(
				i + 20_000_000,
				100,
				RewardDestination::Controller,
			)
			.unwrap();
			assert_ok!(Staking::nominate(Origin::signed(controller), vec![1]));
			some_existing_nominator = controller;
		}

		// one more is too many
		let (_, last_nominator) = testing_utils::create_stash_controller::<Test>(
			30_000_000,
			100,
			RewardDestination::Controller,
		)
		.unwrap();
		assert_noop!(
			Staking::nominate(Origin::signed(last_nominator), vec![1]),
			Error::<Test>::TooManyNominators
		);

		// Re-nominate works fine
		assert_ok!(Staking::nominate(Origin::signed(some_existing_nominator), vec![1]));
		// Re-validate works fine
		assert_ok!(Staking::validate(
			Origin::signed(some_existing_validator),
			ValidatorPrefs::default()
		));

		// No problem when we set to `None` again
		assert_ok!(Staking::set_staking_limits(Origin::root(), 10, 10, None, None, None));
		assert_ok!(Staking::nominate(Origin::signed(last_nominator), vec![1]));
		assert_ok!(Staking::validate(Origin::signed(last_validator), ValidatorPrefs::default()));
	})
}