[Tests] [pallet-timestamp] Add tests for OnTimestampSet. (#11323)

* NF: move tests mod to another file

* NF: separate test setup to mock mod

* test: check if OnTimestampSet ran correctly.

* docs: add license header.

* fixup! NF: separate test setup to mock mod

* NF: formatting changes

substrate/frame/timestamp/src/mock.rs

@@ -0,0 +1,111 @@
+// This file is part of Substrate.
+
+// Copyright (C) 2020-2022 Parity Technologies (UK) Ltd.
+// SPDX-License-Identifier: Apache-2.0
+
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// 	http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+//! Tests Utilities.
+
+use super::*;
+use crate as pallet_timestamp;
+use sp_std::cell::RefCell;
+
+use frame_support::{
+	parameter_types,
+	traits::{ConstU32, ConstU64},
+};
+use sp_core::H256;
+use sp_io::TestExternalities;
+use sp_runtime::{
+	testing::Header,
+	traits::{BlakeTwo256, IdentityLookup},
+};
+
+type UncheckedExtrinsic = frame_system::mocking::MockUncheckedExtrinsic<Test>;
+type Block = frame_system::mocking::MockBlock<Test>;
+type Moment = u64;
+
+frame_support::construct_runtime!(
+	pub enum Test where
+		Block = Block,
+		NodeBlock = Block,
+		UncheckedExtrinsic = UncheckedExtrinsic,
+	{
+		System: frame_system::{Pallet, Call, Config, Storage, Event<T>},
+		Timestamp: pallet_timestamp::{Pallet, Call, Storage, Inherent},
+	}
+);
+
+parameter_types! {
+	pub BlockWeights: frame_system::limits::BlockWeights =
+	frame_system::limits::BlockWeights::simple_max(1024);
+}
+impl frame_system::Config for Test {
+	type BaseCallFilter = frame_support::traits::Everything;
+	type BlockWeights = ();
+	type BlockLength = ();
+	type DbWeight = ();
+	type Origin = Origin;
+	type Index = u64;
+	type BlockNumber = u64;
+	type Call = Call;
+	type Hash = H256;
+	type Hashing = BlakeTwo256;
+	type AccountId = u64;
+	type Lookup = IdentityLookup<Self::AccountId>;
+	type Header = Header;
+	type Event = Event;
+	type BlockHashCount = ConstU64<250>;
+	type Version = ();
+	type PalletInfo = PalletInfo;
+	type AccountData = ();
+	type OnNewAccount = ();
+	type OnKilledAccount = ();
+	type SystemWeightInfo = ();
+	type SS58Prefix = ();
+	type OnSetCode = ();
+	type MaxConsumers = ConstU32<16>;
+}
+
+thread_local! {
+	pub static CAPTURED_MOMENT: RefCell<Option<Moment>> = RefCell::new(None);
+}
+
+pub struct MockOnTimestampSet;
+impl OnTimestampSet<Moment> for MockOnTimestampSet {
+	fn on_timestamp_set(moment: Moment) {
+		CAPTURED_MOMENT.with(|x| *x.borrow_mut() = Some(moment));
+	}
+}
+
+impl Config for Test {
+	type Moment = Moment;
+	type OnTimestampSet = MockOnTimestampSet;
+	type MinimumPeriod = ConstU64<5>;
+	type WeightInfo = ();
+}
+
+pub(crate) fn clear_captured_moment() {
+	CAPTURED_MOMENT.with(|x| *x.borrow_mut() = None);
+}
+
+pub(crate) fn get_captured_moment() -> Option<Moment> {
+	CAPTURED_MOMENT.with(|x| x.borrow().clone())
+}
+
+pub(crate) fn new_test_ext() -> TestExternalities {
+	let t = frame_system::GenesisConfig::default().build_storage::<Test>().unwrap();
+	clear_captured_moment();
+	TestExternalities::new(t)
+}