lib.rs

// This file is part of Substrate.

// Copyright (C) 2017-2022 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.

//! Support code for the runtime.

#![cfg_attr(not(feature = "std"), no_std)]

/// Export ourself as `frame_support` to make tests happy.
extern crate self as frame_support;

#[doc(hidden)]
pub use sp_tracing;

#[doc(hidden)]
pub use codec;
#[doc(hidden)]
pub use frame_metadata as metadata;
#[doc(hidden)]
pub use log;
#[cfg(feature = "std")]
#[doc(hidden)]
pub use once_cell;
#[doc(hidden)]
pub use paste;
#[doc(hidden)]
pub use scale_info;
#[cfg(feature = "std")]
pub use serde;
pub use sp_core::Void;
#[doc(hidden)]
pub use sp_core_hashing_proc_macro;
#[doc(hidden)]
pub use sp_io::{self, storage::root as storage_root};
#[doc(hidden)]
pub use sp_runtime::{RuntimeDebug, StateVersion};
#[cfg(feature = "std")]
#[doc(hidden)]
pub use sp_state_machine::BasicExternalities;
#[doc(hidden)]
pub use sp_std;
#[doc(hidden)]
pub use tt_call::*;

#[macro_use]
pub mod dispatch;
mod hash;
pub mod storage;
#[macro_use]
pub mod event;
pub mod inherent;
#[macro_use]
pub mod error;
pub mod instances;
pub mod migrations;
pub mod traits;
pub mod weights;

#[doc(hidden)]
pub mod unsigned {
	#[doc(hidden)]
	pub use crate::sp_runtime::traits::ValidateUnsigned;
	#[doc(hidden)]
	pub use crate::sp_runtime::transaction_validity::{
		TransactionSource, TransactionValidity, TransactionValidityError, UnknownTransaction,
	};
}

pub use self::{
	dispatch::{Callable, Parameter},
	hash::{
		Blake2_128, Blake2_128Concat, Blake2_256, Hashable, Identity, ReversibleStorageHasher,
		StorageHasher, Twox128, Twox256, Twox64Concat,
	},
	storage::{
		bounded_vec::{BoundedSlice, BoundedVec},
		migration,
		weak_bounded_vec::WeakBoundedVec,
		IterableStorageDoubleMap, IterableStorageMap, IterableStorageNMap, StorageDoubleMap,
		StorageMap, StorageNMap, StoragePrefixedMap, StorageValue,
	},
};
pub use sp_runtime::{self, print, traits::Printable, ConsensusEngineId};

use codec::{Decode, Encode};
use scale_info::TypeInfo;
use sp_runtime::TypeId;

/// A unified log target for support operations.
pub const LOG_TARGET: &'static str = "runtime::frame-support";

/// A type that cannot be instantiated.
#[derive(Debug, PartialEq, Eq, Clone, TypeInfo)]
pub enum Never {}

/// A pallet identifier. These are per pallet and should be stored in a registry somewhere.
#[derive(Clone, Copy, Eq, PartialEq, Encode, Decode, TypeInfo)]
pub struct PalletId(pub [u8; 8]);

impl TypeId for PalletId {
	const TYPE_ID: [u8; 4] = *b"modl";
}

/// Build a bounded vec from the given literals.
///
/// The type of the outcome must be known.
///
/// Will not handle any errors and just panic if the given literals cannot fit in the corresponding
/// bounded vec type. Thus, this is only suitable for testing and non-consensus code.
#[macro_export]
#[cfg(feature = "std")]
macro_rules! bounded_vec {
	($ ($values:expr),* $(,)?) => {
		{
			use $crate::sp_std::convert::TryInto as _;
			$crate::sp_std::vec![$($values),*].try_into().unwrap()
		}
	};
	( $value:expr ; $repetition:expr ) => {
		{
			use $crate::sp_std::convert::TryInto as _;
			$crate::sp_std::vec![$value ; $repetition].try_into().unwrap()
		}
	}
}

/// Generate a new type alias for [`storage::types::StorageValue`],
/// [`storage::types::StorageMap`], [`storage::types::StorageDoubleMap`]
/// and [`storage::types::StorageNMap`].
///
/// Useful for creating a *storage-like* struct for test and migrations.
///
/// ```
/// # use frame_support::generate_storage_alias;
/// use frame_support::codec;
/// use frame_support::Twox64Concat;
/// // generate a storage value with type u32.
/// generate_storage_alias!(Prefix, StorageName => Value<u32>);
///
/// // generate a double map from `(u32, u32)` (with hashers `Twox64Concat` for each key)
/// // to `Vec<u8>`
/// generate_storage_alias!(
/// 	OtherPrefix, OtherStorageName => DoubleMap<
/// 		(Twox64Concat, u32),
/// 		(Twox64Concat, u32),
/// 		Vec<u8>
/// 	>
/// );
///
/// // optionally specify the query type
/// use frame_support::pallet_prelude::{ValueQuery, OptionQuery};
/// generate_storage_alias!(Prefix, ValueName => Value<u32, OptionQuery>);
/// generate_storage_alias!(
/// 	Prefix, SomeStorageName => DoubleMap<
/// 		(Twox64Concat, u32),
/// 		(Twox64Concat, u32),
/// 		Vec<u8>,
/// 		ValueQuery
/// 	>
/// );
///
/// // generate a map from `Config::AccountId` (with hasher `Twox64Concat`) to `Vec<u8>`
/// trait Config { type AccountId: codec::FullCodec; }
/// generate_storage_alias!(
/// 	Prefix, GenericStorage<T: Config> => Map<(Twox64Concat, T::AccountId), Vec<u8>>
/// );
/// # fn main() {}
/// ```
#[macro_export]
macro_rules! generate_storage_alias {
	// without generic for $name.
	($pallet:ident, $name:ident => Map<($hasher:ty, $key:ty), $value:ty $(, $querytype:ty)?>) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			type $name = $crate::storage::types::StorageMap<
				[<$name Instance>],
				$hasher,
				$key,
				$value,
				$( $querytype )?
			>;
		}
	};
	(
		$pallet:ident,
		$name:ident
		=> DoubleMap<($hasher1:ty, $key1:ty), ($hasher2:ty, $key2:ty), $value:ty $(, $querytype:ty)?>
	) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			type $name = $crate::storage::types::StorageDoubleMap<
				[<$name Instance>],
				$hasher1,
				$key1,
				$hasher2,
				$key2,
				$value,
				$( $querytype )?
			>;
		}
	};
	(
		$pallet:ident,
		$name:ident
		=> NMap<Key<$(($hasher:ty, $key:ty)),+>, $value:ty $(, $querytype:ty)?>
	) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			type $name = $crate::storage::types::StorageNMap<
				[<$name Instance>],
				(
					$( $crate::storage::types::Key<$hasher, $key>, )+
				),
				$value,
				$( $querytype )?
			>;
		}
	};
	($pallet:ident, $name:ident => Value<$value:ty $(, $querytype:ty)?>) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			type $name = $crate::storage::types::StorageValue<
				[<$name Instance>],
				$value,
				$( $querytype )?
			>;
		}
	};
	// with generic for $name.
	(
		$pallet:ident,
		$name:ident<$t:ident : $bounds:tt>
		=> Map<($hasher:ty, $key:ty), $value:ty $(, $querytype:ty)?>
	) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			#[allow(type_alias_bounds)]
			type $name<$t : $bounds> = $crate::storage::types::StorageMap<
				[<$name Instance>],
				$hasher,
				$key,
				$value,
				$( $querytype )?
			>;
		}
	};
	(
		$pallet:ident,
		$name:ident<$t:ident : $bounds:tt>
		=> DoubleMap<($hasher1:ty, $key1:ty), ($hasher2:ty, $key2:ty), $value:ty $(, $querytype:ty)?>
	) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			#[allow(type_alias_bounds)]
			type $name<$t : $bounds> = $crate::storage::types::StorageDoubleMap<
				[<$name Instance>],
				$hasher1,
				$key1,
				$hasher2,
				$key2,
				$value,
				$( $querytype )?
			>;
		}
	};
	(
		$pallet:ident,
		$name:ident<$t:ident : $bounds:tt>
		=> NMap<$(($hasher:ty, $key:ty),)+ $value:ty $(, $querytype:ty)?>
	) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			#[allow(type_alias_bounds)]
			type $name<$t : $bounds> = $crate::storage::types::StorageNMap<
				[<$name Instance>],
				(
					$( $crate::storage::types::Key<$hasher, $key>, )+
				),
				$value,
				$( $querytype )?
			>;
		}
	};
	($pallet:ident, $name:ident<$t:ident : $bounds:tt> => Value<$value:ty $(, $querytype:ty)?>) => {
		$crate::paste::paste! {
			$crate::generate_storage_alias!(@GENERATE_INSTANCE_STRUCT $pallet, $name);
			#[allow(type_alias_bounds)]
			type $name<$t : $bounds> = $crate::storage::types::StorageValue<
				[<$name Instance>],
				$value,
				$( $querytype )?
			>;
		}
	};
	// helper used in all arms.
	(@GENERATE_INSTANCE_STRUCT $pallet:ident, $name:ident) => {
		$crate::paste::paste! {
			struct [<$name Instance>];
			impl $crate::traits::StorageInstance for [<$name Instance>] {
				fn pallet_prefix() -> &'static str { stringify!($pallet) }
				const STORAGE_PREFIX: &'static str = stringify!($name);
			}
		}
	};
}

/// Create new implementations of the [`Get`](crate::traits::Get) trait.
///
/// The so-called parameter type can be created in four different ways:
///
/// - Using `const` to create a parameter type that provides a `const` getter. It is required that
///   the `value` is const.
///
/// - Declare the parameter type without `const` to have more freedom when creating the value.
///
/// - Using `storage` to create a storage parameter type. This type is special as it tries to load
///   the value from the storage under a fixed key. If the value could not be found in the storage,
///   the given default value will be returned. It is required that the value implements
///   [`Encode`](codec::Encode) and [`Decode`](codec::Decode). The key for looking up the value in
///   the storage is built using the following formula:
///
///   `twox_128(":" ++ NAME ++ ":")` where `NAME` is the name that is passed as type name.
///
/// - Using `static` to create a static parameter type. Its value is being provided by a static
///   variable with the equivalent name in `UPPER_SNAKE_CASE`. An additional `set` function is
///   provided in this case to alter the static variable. **This is intended for testing ONLY and is
///   ONLY available when `std` is enabled.**
///
/// # Examples
///
/// ```
/// # use frame_support::traits::Get;
/// # use frame_support::parameter_types;
/// // This function cannot be used in a const context.
/// fn non_const_expression() -> u64 { 99 }
///
/// const FIXED_VALUE: u64 = 10;
/// parameter_types! {
///    pub const Argument: u64 = 42 + FIXED_VALUE;
///    /// Visibility of the type is optional
///    OtherArgument: u64 = non_const_expression();
///    pub storage StorageArgument: u64 = 5;
///    pub static StaticArgument: u32 = 7;
/// }
///
/// trait Config {
///    type Parameter: Get<u64>;
///    type OtherParameter: Get<u64>;
///    type StorageParameter: Get<u64>;
///    type StaticParameter: Get<u32>;
/// }
///
/// struct Runtime;
/// impl Config for Runtime {
///    type Parameter = Argument;
///    type OtherParameter = OtherArgument;
///    type StorageParameter = StorageArgument;
///    type StaticParameter = StaticArgument;
/// }
///
/// // In testing, `StaticArgument` can be altered later: `StaticArgument::set(8)`.
/// ```
///
/// # Invalid example:
///
/// ```compile_fail
/// # use frame_support::traits::Get;
/// # use frame_support::parameter_types;
/// // This function cannot be used in a const context.
/// fn non_const_expression() -> u64 { 99 }
///
/// parameter_types! {
///    pub const Argument: u64 = non_const_expression();
/// }
/// ```
#[macro_export]
macro_rules! parameter_types {
	(
		$( #[ $attr:meta ] )*
		$vis:vis const $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name;
		$crate::parameter_types!(IMPL_CONST $name , $type , $value);
		$crate::parameter_types!( $( $rest )* );
	);
	(
		$( #[ $attr:meta ] )*
		$vis:vis $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name;
		$crate::parameter_types!(IMPL $name, $type, $value);
		$crate::parameter_types!( $( $rest )* );
	);
	(
		$( #[ $attr:meta ] )*
		$vis:vis storage $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name;
		$crate::parameter_types!(IMPL_STORAGE $name, $type, $value);
		$crate::parameter_types!( $( $rest )* );
	);
	() => ();
	(IMPL_CONST $name:ident, $type:ty, $value:expr) => {
		impl $name {
			/// Returns the value of this parameter type.
			pub const fn get() -> $type {
				$value
			}
		}

		impl<I: From<$type>> $crate::traits::Get<I> for $name {
			fn get() -> I {
				I::from(Self::get())
			}
		}
	};
	(IMPL $name:ident, $type:ty, $value:expr) => {
		impl $name {
			/// Returns the value of this parameter type.
			pub fn get() -> $type {
				$value
			}
		}

		impl<I: From<$type>> $crate::traits::Get<I> for $name {
			fn get() -> I {
				I::from(Self::get())
			}
		}
	};
	(IMPL_STORAGE $name:ident, $type:ty, $value:expr) => {
		impl $name {
			/// Returns the key for this parameter type.
			#[allow(unused)]
			pub fn key() -> [u8; 16] {
				$crate::sp_core_hashing_proc_macro::twox_128!(b":", $name, b":")
			}

			/// Set the value of this parameter type in the storage.
			///
			/// This needs to be executed in an externalities provided
			/// environment.
			#[allow(unused)]
			pub fn set(value: &$type) {
				$crate::storage::unhashed::put(&Self::key(), value);
			}

			/// Returns the value of this parameter type.
			///
			/// This needs to be executed in an externalities provided
			/// environment.
			#[allow(unused)]
			pub fn get() -> $type {
				$crate::storage::unhashed::get(&Self::key()).unwrap_or_else(|| $value)
			}
		}

		impl<I: From<$type>> $crate::traits::Get<I> for $name {
			fn get() -> I {
				I::from(Self::get())
			}
		}
	};
	(
		$( #[ $attr:meta ] )*
		$vis:vis static $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$crate::parameter_types_impl_thread_local!(
			$( #[ $attr ] )*
			$vis static $name: $type = $value;
		);
		$crate::parameter_types!( $( $rest )* );
	);
}

#[cfg(not(feature = "std"))]
#[macro_export]
macro_rules! parameter_types_impl_thread_local {
	( $( $any:tt )* ) => {
		compile_error!("static parameter types is only available in std and for testing.");
	};
}

#[cfg(feature = "std")]
#[macro_export]
macro_rules! parameter_types_impl_thread_local {
	(
		$(
			$( #[ $attr:meta ] )*
			$vis:vis static $name:ident: $type:ty = $value:expr;
		)*
	) => {
		$crate::parameter_types_impl_thread_local!(
			IMPL_THREAD_LOCAL $( $vis, $name, $type, $value, )*
		);
		$crate::paste::item! {
			$crate::parameter_types!(
				$(
					$( #[ $attr ] )*
					$vis $name: $type = [<$name:snake:upper>].with(|v| v.borrow().clone());
				)*
			);
			$(
				impl $name {
					/// Set the internal value.
					pub fn set(t: $type) {
						[<$name:snake:upper>].with(|v| *v.borrow_mut() = t);
					}
				}
			)*
		}
	};
	(IMPL_THREAD_LOCAL $( $vis:vis, $name:ident, $type:ty, $value:expr, )* ) => {
		$crate::paste::item! {
			thread_local! {
				$(
					pub static [<$name:snake:upper>]: std::cell::RefCell<$type> =
						std::cell::RefCell::new($value);
				)*
			}
		}
	};
}

/// Macro for easily creating a new implementation of both the `Get` and `Contains` traits. Use
/// exactly as with `parameter_types`, only the type must be `Ord`.
#[macro_export]
macro_rules! ord_parameter_types {
	(
		$( #[ $attr:meta ] )*
		$vis:vis const $name:ident: $type:ty = $value:expr;
		$( $rest:tt )*
	) => (
		$( #[ $attr ] )*
		$vis struct $name;
		$crate::parameter_types!{IMPL $name , $type , $value}
		$crate::ord_parameter_types!{IMPL $name , $type , $value}
		$crate::ord_parameter_types!{ $( $rest )* }
	);
	() => ();
	(IMPL $name:ident , $type:ty , $value:expr) => {
		impl $crate::traits::SortedMembers<$type> for $name {
			fn contains(t: &$type) -> bool { &$value == t }
			fn sorted_members() -> $crate::sp_std::prelude::Vec<$type> { vec![$value] }
			fn count() -> usize { 1 }
			#[cfg(feature = "runtime-benchmarks")]
			fn add(_: &$type) {}
		}
		impl $crate::traits::Contains<$type> for $name {
			fn contains(t: &$type) -> bool { &$value == t }
		}
	}
}

/// Print out a formatted message.
///
/// # Example
///
/// ```
/// frame_support::runtime_print!("my value is {}", 3);
/// ```
#[macro_export]
macro_rules! runtime_print {
	($($arg:tt)+) => {
		{
			use core::fmt::Write;
			let mut w = $crate::sp_std::Writer::default();
			let _ = core::write!(&mut w, $($arg)+);
			$crate::sp_io::misc::print_utf8(&w.inner())
		}
	}
}

/// Print out the debuggable type.
pub fn debug(data: &impl sp_std::fmt::Debug) {
	runtime_print!("{:?}", data);
}

#[doc(inline)]
pub use frame_support_procedural::{
	construct_runtime, decl_storage, match_and_insert, transactional, RuntimeDebugNoBound,
};

#[doc(hidden)]
pub use frame_support_procedural::__generate_dummy_part_checker;

/// Derive [`Clone`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::CloneNoBound;
/// trait Config {
/// 		type C: Clone;
/// }
///
/// // Foo implements [`Clone`] because `C` bounds [`Clone`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Clone`].
/// #[derive(CloneNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::CloneNoBound;

/// Derive [`Eq`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::{EqNoBound, PartialEqNoBound};
/// trait Config {
/// 		type C: Eq;
/// }
///
/// // Foo implements [`Eq`] because `C` bounds [`Eq`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Eq`].
/// #[derive(PartialEqNoBound, EqNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::EqNoBound;

/// Derive [`PartialEq`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::PartialEqNoBound;
/// trait Config {
/// 		type C: PartialEq;
/// }
///
/// // Foo implements [`PartialEq`] because `C` bounds [`PartialEq`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`PartialEq`].
/// #[derive(PartialEqNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::PartialEqNoBound;

/// Derive [`Debug`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::DebugNoBound;
/// # use core::fmt::Debug;
/// trait Config {
/// 		type C: Debug;
/// }
///
/// // Foo implements [`Debug`] because `C` bounds [`Debug`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Debug`].
/// #[derive(DebugNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::DebugNoBound;

/// Derive [`Default`] but do not bound any generic.
///
/// This is useful for type generic over runtime:
/// ```
/// # use frame_support::DefaultNoBound;
/// # use core::default::Default;
/// trait Config {
/// 		type C: Default;
/// }
///
/// // Foo implements [`Default`] because `C` bounds [`Default`].
/// // Otherwise compilation will fail with an output telling `c` doesn't implement [`Default`].
/// #[derive(DefaultNoBound)]
/// struct Foo<T: Config> {
/// 		c: T::C,
/// }
/// ```
pub use frame_support_procedural::DefaultNoBound;

/// Assert the annotated function is executed within a storage transaction.
///
/// The assertion is enabled for native execution and when `debug_assertions` are enabled.
///
/// # Example
///
/// ```
/// # use frame_support::{
/// # 	require_transactional, transactional, dispatch::DispatchResult
/// # };
///
/// #[require_transactional]
/// fn update_all(value: u32) -> DispatchResult {
/// 	// Update multiple storages.
/// 	// Return `Err` to indicate should revert.
/// 	Ok(())
/// }
///
/// #[transactional]
/// fn safe_update(value: u32) -> DispatchResult {
/// 	// This is safe
/// 	update_all(value)
/// }
///
/// fn unsafe_update(value: u32) -> DispatchResult {
/// 	// this may panic if unsafe_update is not called within a storage transaction
/// 	update_all(value)
/// }
/// ```
pub use frame_support_procedural::require_transactional;

/// Convert the current crate version into a [`CrateVersion`](crate::traits::CrateVersion).
///
/// It uses the `CARGO_PKG_VERSION_MAJOR`, `CARGO_PKG_VERSION_MINOR` and
/// `CARGO_PKG_VERSION_PATCH` environment variables to fetch the crate version.
/// This means that the [`CrateVersion`](crate::traits::CrateVersion)
/// object will correspond to the version of the crate the macro is called in!
///
/// # Example
///
/// ```
/// # use frame_support::{traits::CrateVersion, crate_to_crate_version};
/// const Version: CrateVersion = crate_to_crate_version!();
/// ```
pub use frame_support_procedural::crate_to_crate_version;

/// Return Err of the expression: `return Err($expression);`.
///
/// Used as `fail!(expression)`.
#[macro_export]
macro_rules! fail {
	( $y:expr ) => {{
		return Err($y.into())
	}};
}

/// Evaluate `$x:expr` and if not true return `Err($y:expr)`.
///
/// Used as `ensure!(expression_to_ensure, expression_to_return_on_false)`.
#[macro_export]
macro_rules! ensure {
	( $x:expr, $y:expr $(,)? ) => {{
		if !$x {
			$crate::fail!($y);
		}
	}};
}

/// Evaluate an expression, assert it returns an expected `Err` value and that
/// runtime storage has not been mutated (i.e. expression is a no-operation).
///
/// Used as `assert_noop(expression_to_assert, expected_error_expression)`.
#[macro_export]
macro_rules! assert_noop {
	(
		$x:expr,
		$y:expr $(,)?
	) => {
		let h = $crate::storage_root($crate::StateVersion::V1);
		$crate::assert_err!($x, $y);
		assert_eq!(h, $crate::storage_root($crate::StateVersion::V1));
	};
}

/// Evaluate any expression and assert that runtime storage has not been mutated
/// (i.e. expression is a storage no-operation).
///
/// Used as `assert_storage_noop(expression_to_assert)`.
#[macro_export]
macro_rules! assert_storage_noop {
	(
		$x:expr
	) => {
		let h = $crate::storage_root($crate::StateVersion::V1);
		$x;
		assert_eq!(h, $crate::storage_root($crate::StateVersion::V1));
	};
}

/// Assert an expression returns an error specified.
///
/// Used as `assert_err!(expression_to_assert, expected_error_expression)`
#[macro_export]
macro_rules! assert_err {
	( $x:expr , $y:expr $(,)? ) => {
		assert_eq!($x, Err($y.into()));
	};
}

/// Assert an expression returns an error specified.
///
/// This can be used on`DispatchResultWithPostInfo` when the post info should
/// be ignored.
#[macro_export]
macro_rules! assert_err_ignore_postinfo {
	( $x:expr , $y:expr $(,)? ) => {
		$crate::assert_err!($x.map(|_| ()).map_err(|e| e.error), $y);
	};
}

/// Assert an expression returns error with the given weight.
#[macro_export]
macro_rules! assert_err_with_weight {
	($call:expr, $err:expr, $weight:expr $(,)? ) => {
		if let Err(dispatch_err_with_post) = $call {
			$crate::assert_err!($call.map(|_| ()).map_err(|e| e.error), $err);
			assert_eq!(dispatch_err_with_post.post_info.actual_weight, $weight.into());
		} else {
			panic!("expected Err(_), got Ok(_).")
		}
	};
}

/// Panic if an expression doesn't evaluate to `Ok`.
///
/// Used as `assert_ok!(expression_to_assert, expected_ok_expression)`,
/// or `assert_ok!(expression_to_assert)` which would assert against `Ok(())`.
#[macro_export]
macro_rules! assert_ok {
	( $x:expr $(,)? ) => {
		let is = $x;
		match is {
			Ok(_) => (),
			_ => assert!(false, "Expected Ok(_). Got {:#?}", is),
		}
	};
	( $x:expr, $y:expr $(,)? ) => {
		assert_eq!($x, Ok($y));
	};
}

#[cfg(feature = "std")]
#[doc(hidden)]
pub use serde::{Deserialize, Serialize};

#[cfg(test)]
pub mod tests {
	use super::*;
	use crate::metadata::{
		PalletStorageMetadata, StorageEntryMetadata, StorageEntryModifier, StorageEntryType,
		StorageHasher,
	};
	use codec::{Codec, EncodeLike};
	use frame_support::traits::CrateVersion;
	use sp_io::TestExternalities;
	use sp_std::result;

	/// A PalletInfo implementation which just panics.
	pub struct PanicPalletInfo;

	impl crate::traits::PalletInfo for PanicPalletInfo {
		fn index<P: 'static>() -> Option<usize> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn name<P: 'static>() -> Option<&'static str> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn module_name<P: 'static>() -> Option<&'static str> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
		fn crate_version<P: 'static>() -> Option<CrateVersion> {
			unimplemented!("PanicPalletInfo mustn't be triggered by tests");
		}
	}

	pub trait Config: 'static {
		type BlockNumber: Codec + EncodeLike + Default + TypeInfo;
		type Origin;
		type PalletInfo: crate::traits::PalletInfo;
		type DbWeight: crate::traits::Get<crate::weights::RuntimeDbWeight>;
	}

	mod module {
		#![allow(dead_code)]

		use super::Config;

		decl_module! {
			pub struct Module<T: Config> for enum Call where origin: T::Origin, system=self  {}
		}
	}
	use self::module::Module;

	decl_storage! {
		trait Store for Module<T: Config> as Test {
			pub Data get(fn data) build(|_| vec![(15u32, 42u64)]):
				map hasher(twox_64_concat) u32 => u64;
			pub OptionLinkedMap: map hasher(blake2_128_concat) u32 => Option<u32>;
			pub GenericData get(fn generic_data):
				map hasher(identity) T::BlockNumber => T::BlockNumber;
			pub GenericData2 get(fn generic_data2):
				map hasher(blake2_128_concat) T::BlockNumber => Option<T::BlockNumber>;
			pub DataDM config(test_config) build(|_| vec![(15u32, 16u32, 42u64)]):
				double_map hasher(twox_64_concat) u32, hasher(blake2_128_concat) u32 => u64;
			pub GenericDataDM:
				double_map hasher(blake2_128_concat) T::BlockNumber, hasher(identity) T::BlockNumber
				=> T::BlockNumber;
			pub GenericData2DM:
				double_map hasher(blake2_128_concat) T::BlockNumber, hasher(twox_64_concat) T::BlockNumber
				=> Option<T::BlockNumber>;
			pub AppendableDM:
				double_map hasher(blake2_128_concat) u32, hasher(blake2_128_concat) T::BlockNumber => Vec<u32>;
		}
	}

	struct Test;
	impl Config for Test {
		type BlockNumber = u32;
		type Origin = u32;
		type PalletInfo = PanicPalletInfo;
		type DbWeight = ();
	}

	fn new_test_ext() -> TestExternalities {
		GenesisConfig::default().build_storage().unwrap().into()
	}

	type Map = Data;

	trait Sorted {
		fn sorted(self) -> Self;
	}
	impl<T: Ord> Sorted for Vec<T> {
		fn sorted(mut self) -> Self {
			self.sort();
			self
		}
	}

	#[test]
	fn generate_storage_alias_works() {
		new_test_ext().execute_with(|| {
			generate_storage_alias!(
				Test,
				GenericData2<T: Config> => Map<(Blake2_128Concat, T::BlockNumber), T::BlockNumber>
			);

			assert_eq!(Module::<Test>::generic_data2(5), None);
			GenericData2::<Test>::insert(5, 5);
			assert_eq!(Module::<Test>::generic_data2(5), Some(5));
		});
	}

	#[test]
	fn map_issue_3318() {
		new_test_ext().execute_with(|| {
			OptionLinkedMap::insert(1, 1);
			assert_eq!(OptionLinkedMap::get(1), Some(1));
			OptionLinkedMap::insert(1, 2);
			assert_eq!(OptionLinkedMap::get(1), Some(2));
		});
	}

	#[test]
	fn map_swap_works() {
		new_test_ext().execute_with(|| {
			OptionLinkedMap::insert(0, 0);
			OptionLinkedMap::insert(1, 1);
			OptionLinkedMap::insert(2, 2);
			OptionLinkedMap::insert(3, 3);

			let collect = || OptionLinkedMap::iter().collect::<Vec<_>>().sorted();
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);

			// Two existing
			OptionLinkedMap::swap(1, 2);
			assert_eq!(collect(), vec![(0, 0), (1, 2), (2, 1), (3, 3)]);

			// Back to normal
			OptionLinkedMap::swap(2, 1);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);

			// Left existing
			OptionLinkedMap::swap(2, 5);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (3, 3), (5, 2)]);

			// Right existing
			OptionLinkedMap::swap(5, 2);
			assert_eq!(collect(), vec![(0, 0), (1, 1), (2, 2), (3, 3)]);
		});
	}