Make constants exposable in metadata (#2975)

* Some cleanup * Add module constant metadata declaration * Begin to integrate the constants in `decl_module` * Fixes tests * Fix compilation and add tests * Remove duplicate code * Expose constants in democracy and staking + further fixes * Update srml/metadata/src/lib.rs Co-Authored-By: YJ <yjkimjunior@gmail.com> * Hide `RawEvent` metadata function * Prevent whitespaces in types * Fix `offchain_worker` and `constants` with instances * Up the `impl_version` * Fix macro * Incrase impl_version
2026-04-28 10:57:56 +00:00 · 2019-07-01 10:05:28 +02:00
parent 5f1538b834
commit 7202403bfc
12 changed files with 858 additions and 580 deletions
@@ -59,7 +59,7 @@ pub const VERSION: RuntimeVersion = RuntimeVersion {
 	impl_name: create_runtime_str!("substrate-node"),
 	authoring_version: 10,
 	spec_version: 99,
-	impl_version: 105,
+	impl_version: 106,
 	apis: RUNTIME_API_VERSIONS,
 };

@@ -176,6 +176,7 @@ parameter_types! {
 	pub const EnactmentPeriod: BlockNumber = 30 * 24 * 60 * MINUTES;
 	pub const CooloffPeriod: BlockNumber = 30 * 24 * 60 * MINUTES;
 }
+
 impl democracy::Trait for Runtime {
 	type Proposal = Call;
 	type Event = Event;
@@ -497,9 +497,7 @@ mod tests {
 					author_a,
 				);

-				assert!(
-					Authorship::verify_and_import_uncles(vec![uncle_a.clone()]).is_ok()
-				);
+				assert!(Authorship::verify_and_import_uncles(vec![uncle_a.clone()]).is_ok());

 				assert_eq!(
 					Authorship::verify_and_import_uncles(vec![uncle_a.clone()]),
@@ -549,9 +547,7 @@ mod tests {
 					author_a,
 				);

-				assert!(
-					Authorship::verify_and_import_uncles(vec![other_8]).is_ok()
-				);
+				assert!(Authorship::verify_and_import_uncles(vec![other_8]).is_ok());
 			}
 		});
 	}
@@ -241,7 +241,6 @@ impl<BlockNumber: Parameter, Proposal: Parameter> ReferendumInfo<BlockNumber, Pr

 decl_storage! {
 	trait Store for Module<T: Trait> as Democracy {
-
 		/// The number of (public) proposals that have been made so far.
 		pub PublicPropCount get(public_prop_count) build(|_| 0 as PropIndex) : PropIndex;
 		/// The public proposals. Unsorted.
@@ -318,6 +317,28 @@ decl_event!(

 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		/// The minimum period of locking and the period between a proposal being approved and enacted.
+		///
+		/// It should generally be a little more than the unstake period to ensure that
+		/// voting stakers have an opportunity to remove themselves from the system in the case where
+		/// they are on the losing side of a vote.
+		const EnactmentPeriod: T::BlockNumber = T::EnactmentPeriod::get();
+
+		/// How often (in blocks) new public referenda are launched.
+		const LaunchPeriod: T::BlockNumber = T::LaunchPeriod::get();
+
+		/// How often (in blocks) to check for new votes.
+		const VotingPeriod: T::BlockNumber = T::VotingPeriod::get();
+
+		/// The minimum amount to be used as a deposit for a public referendum proposal.
+		const MinimumDeposit: BalanceOf<T> = T::MinimumDeposit::get();
+
+		/// Minimum voting period allowed for an emergency referendum.
+		const EmergencyVotingPeriod: T::BlockNumber = T::EmergencyVotingPeriod::get();
+
+		/// Period in blocks where an external proposal may not be re-submitted after being vetoed.
+		const CooloffPeriod: T::BlockNumber = T::CooloffPeriod::get();
+
 		fn deposit_event<T>() = default;

 		/// Propose a sensitive action to be taken.
@@ -102,10 +102,7 @@ impl<B, O> serde::Serialize for DecodeDifferent<B, O>
 		B: serde::Serialize + 'static,
 		O: serde::Serialize + 'static,
 {
-	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-		where
-				S: serde::Serializer,
-	{
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: serde::Serializer {
 		match self {
 			DecodeDifferent::Encode(b) => b.serialize(serializer),
 			DecodeDifferent::Decoded(o) => o.serialize(serializer),
@@ -162,10 +159,7 @@ impl<E: Encode + ::std::fmt::Debug> std::fmt::Debug for FnEncode<E> {

 #[cfg(feature = "std")]
 impl<E: Encode + serde::Serialize> serde::Serialize for FnEncode<E> {
-	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-		where
-				S: serde::Serializer,
-	{
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: serde::Serializer {
 		self.0().serialize(serializer)
 	}
 }
@@ -190,21 +184,24 @@ pub struct EventMetadata {
 	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
 }

-/// All the metadata about a storage.
+/// All the metadata about one storage entry.
 #[derive(Clone, PartialEq, Eq, Encode)]
 #[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
-pub struct StorageMetadata {
-	pub functions: DecodeDifferentArray<StorageFunctionMetadata>,
+pub struct StorageEntryMetadata {
+	pub name: DecodeDifferentStr,
+	pub modifier: StorageEntryModifier,
+	pub ty: StorageEntryType,
+	pub default: ByteGetter,
+	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
 }

-/// All the metadata about a storage function.
+/// All the metadata about one module constant.
 #[derive(Clone, PartialEq, Eq, Encode)]
 #[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
-pub struct StorageFunctionMetadata {
+pub struct ModuleConstantMetadata {
 	pub name: DecodeDifferentStr,
-	pub modifier: StorageFunctionModifier,
-	pub ty: StorageFunctionType,
-	pub default: ByteGetter,
+	pub ty: DecodeDifferentStr,
+	pub value: ByteGetter,
 	pub documentation: DecodeDifferentArray<&'static str, StringBuf>,
 }

@@ -238,10 +235,7 @@ impl Eq for DefaultByteGetter { }

 #[cfg(feature = "std")]
 impl serde::Serialize for DefaultByteGetter {
-	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error>
-		where
-				S: serde::Serializer,
-	{
+	fn serialize<S>(&self, serializer: S) -> Result<S::Ok, S::Error> where S: serde::Serializer {
 		self.0.default_byte().serialize(serializer)
 	}
 }
@@ -264,10 +258,10 @@ pub enum StorageHasher {
 	Twox64Concat,
 }

-/// A storage function type.
+/// A storage entry type.
 #[derive(Clone, PartialEq, Eq, Encode)]
 #[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
-pub enum StorageFunctionType {
+pub enum StorageEntryType {
 	Plain(DecodeDifferentStr),
 	Map {
 		hasher: StorageHasher,
@@ -284,10 +278,10 @@ pub enum StorageFunctionType {
 	},
 }

-/// A storage function modifier.
+/// A storage entry modifier.
 #[derive(Clone, PartialEq, Eq, Encode)]
 #[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
-pub enum StorageFunctionModifier {
+pub enum StorageEntryModifier {
 	Optional,
 	Default,
 }
@@ -313,8 +307,10 @@ pub enum RuntimeMetadata {
 	V3(RuntimeMetadataDeprecated),
 	/// Version 4 for runtime metadata. No longer used.
 	V4(RuntimeMetadataDeprecated),
-	/// Version 5 for runtime metadata.
-	V5(RuntimeMetadataV5),
+	/// Version 5 for runtime metadata. No longer used.
+	V5(RuntimeMetadataDeprecated),
+	/// Version 6 for runtime metadata.
+	V6(RuntimeMetadataV6),
 }

 /// Enum that should fail.
@@ -323,8 +319,7 @@ pub enum RuntimeMetadata {
 pub enum RuntimeMetadataDeprecated { }

 impl Encode for RuntimeMetadataDeprecated {
-	fn encode_to<W: Output>(&self, _dest: &mut W) {
-	}
+	fn encode_to<W: Output>(&self, _dest: &mut W) {}
 }

 #[cfg(feature = "std")]
@@ -337,7 +332,7 @@ impl Decode for RuntimeMetadataDeprecated {
 /// The metadata of a runtime.
 #[derive(Eq, Encode, PartialEq)]
 #[cfg_attr(feature = "std", derive(Decode, Debug, Serialize))]
-pub struct RuntimeMetadataV5 {
+pub struct RuntimeMetadataV6 {
 	pub modules: DecodeDifferentArray<ModuleMetadata>,
 }

@@ -347,12 +342,14 @@ pub struct RuntimeMetadataV5 {
 pub struct ModuleMetadata {
 	pub name: DecodeDifferentStr,
 	pub prefix: DecodeDifferent<FnEncode<&'static str>, StringBuf>,
-	pub storage: ODFnA<StorageFunctionMetadata>,
+	pub storage: ODFnA<StorageEntryMetadata>,
 	pub calls: ODFnA<FunctionMetadata>,
 	pub event: ODFnA<EventMetadata>,
+	pub constants: DFnA<ModuleConstantMetadata>,
 }

-type ODFnA<T> = Option<DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>>;
+type ODFnA<T> = Option<DFnA<T>>;
+type DFnA<T> = DecodeDifferent<FnEncode<&'static [T]>, Vec<T>>;

 impl Into<primitives::OpaqueMetadata> for RuntimeMetadataPrefixed {
 	fn into(self) -> primitives::OpaqueMetadata {
@@ -607,6 +607,12 @@ decl_event!(

 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		/// Number of sessions per era.
+		const SessionsPerEra: SessionIndex = T::SessionsPerEra::get();
+
+		/// Number of eras that staked funds must remain bonded for.
+		const BondingDuration: EraIndex = T::BondingDuration::get();
+
 		fn deposit_event<T>() = default;

 		/// Take the origin account as a stash and lock up `value` of its balance. `controller` will
@@ -162,13 +162,7 @@ pub fn decl_storage_impl(input: TokenStream) -> TokenStream {
 		impl<#traitinstance: 'static + #traittype, #instance #bound_instantiable> #module_ident<#traitinstance, #instance> {
 			#impl_store_fns
 			#[doc(hidden)]
-			pub fn store_metadata() -> #scrate::metadata::StorageMetadata {
-				#scrate::metadata::StorageMetadata {
-					functions: #scrate::metadata::DecodeDifferent::Encode(#store_functions_to_metadata) ,
-				}
-			}
-			#[doc(hidden)]
-			pub fn store_metadata_functions() -> &'static [#scrate::metadata::StorageFunctionMetadata] {
+			pub fn store_metadata_functions() -> &'static [#scrate::metadata::StorageEntryMetadata] {
 				#store_functions_to_metadata
 			}
 			#[doc(hidden)]
@@ -934,7 +928,7 @@ fn store_functions_to_metadata (
 		let stype = match type_infos.kind {
 			DeclStorageTypeInfosKind::Simple => {
 				quote!{
-					#scrate::metadata::StorageFunctionType::Plain(
+					#scrate::metadata::StorageEntryType::Plain(
 						#scrate::metadata::DecodeDifferent::Encode(#styp),
 					)
 				}
@@ -943,7 +937,7 @@ fn store_functions_to_metadata (
 				let hasher = hasher.into_metadata();
 				let kty = clean_type_string(&quote!(#key_type).to_string());
 				quote!{
-					#scrate::metadata::StorageFunctionType::Map {
+					#scrate::metadata::StorageEntryType::Map {
 						hasher: #scrate::metadata::#hasher,
 						key: #scrate::metadata::DecodeDifferent::Encode(#kty),
 						value: #scrate::metadata::DecodeDifferent::Encode(#styp),
@@ -957,7 +951,7 @@ fn store_functions_to_metadata (
 				let k2ty = clean_type_string(&quote!(#key2_type).to_string());
 				let k2_hasher = key2_hasher.into_metadata();
 				quote!{
-					#scrate::metadata::StorageFunctionType::DoubleMap {
+					#scrate::metadata::StorageEntryType::DoubleMap {
 						hasher: #scrate::metadata::#hasher,
 						key1: #scrate::metadata::DecodeDifferent::Encode(#k1ty),
 						key2: #scrate::metadata::DecodeDifferent::Encode(#k2ty),
@@ -969,11 +963,11 @@ fn store_functions_to_metadata (
 		};
 		let modifier = if type_infos.is_option {
 			quote!{
-				#scrate::metadata::StorageFunctionModifier::Optional
+				#scrate::metadata::StorageEntryModifier::Optional
 			}
 		} else {
 			quote!{
-				#scrate::metadata::StorageFunctionModifier::Default
+				#scrate::metadata::StorageEntryModifier::Default
 			}
 		};
 		let default = default_value.inner.as_ref().map(|d| &d.expr)
@@ -998,7 +992,7 @@ fn store_functions_to_metadata (
 		let cache_name = proc_macro2::Ident::new(&("__CACHE_GET_BYTE_STRUCT_".to_string() + &str_name), name.span());

 		let item = quote! {
-			#scrate::metadata::StorageFunctionMetadata {
+			#scrate::metadata::StorageEntryMetadata {
 				name: #scrate::metadata::DecodeDifferent::Encode(#str_name),
 				modifier: #modifier,
 				ty: #stype,
@@ -17,12 +17,14 @@
 //! Dispatch system. Contains a macro for defining runtime modules and
 //! generating values representing lazy module function calls.

-pub use crate::rstd::prelude::{Vec, Clone, Eq, PartialEq};
+pub use crate::rstd::{result, prelude::{Vec, Clone, Eq, PartialEq}, marker};
 #[cfg(feature = "std")]
 pub use std::fmt;
-pub use crate::rstd::result;
 pub use crate::codec::{Codec, Decode, Encode, Input, Output, HasCompact, EncodeAsRef};
-pub use srml_metadata::{FunctionMetadata, DecodeDifferent, DecodeDifferentArray, FunctionArgumentMetadata};
+pub use srml_metadata::{
+	FunctionMetadata, DecodeDifferent, DecodeDifferentArray, FunctionArgumentMetadata,
+	ModuleConstantMetadata, DefaultByte, DefaultByteGetter,
+};
 pub use sr_primitives::weights::{TransactionWeight, Weighable, Weight};

 /// A type that cannot be instantiated.
@@ -217,6 +219,7 @@ macro_rules! decl_module {
 			{}
 			{}
 			{}
+			{}
 			[]
 			$($t)*
 		);
@@ -237,6 +240,7 @@ macro_rules! decl_module {
 			{}
 			{}
 			{}
+			{}
 			[]
 			$($t)*
 		);
@@ -251,7 +255,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$vis:vis fn deposit_event $(<$dpeg:ident $(, $dpeg_instance:ident)?>)* () = default;
 		$($rest:tt)*
@@ -264,7 +269,8 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$($rest)*
 		);
 	};
@@ -276,7 +282,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$vis:vis fn deposit_event $(<$dpeg:ident $(, $dpeg_instance:ident)?>)* (
 			$($param_name:ident : $param:ty),*
@@ -291,7 +298,8 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$($rest)*
 		);
 	};
@@ -303,7 +311,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{}
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		fn on_finalize($($param_name:ident : $param:ty),* ) { $( $impl:tt )* }
 		$($rest:tt)*
@@ -316,7 +325,8 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ fn on_finalize( $( $param_name : $param ),* ) { $( $impl )* } }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$($rest)*
 		);
 	};
@@ -328,7 +338,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{}
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		fn on_finalise($($param_name:ident : $param:ty),* ) { $( $impl:tt )* }
 		$($rest:tt)*
@@ -345,7 +356,8 @@ macro_rules! decl_module {
 		{}
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		fn on_initialize($($param_name:ident : $param:ty),* ) { $( $impl:tt )* }
 		$($rest:tt)*
@@ -358,7 +370,8 @@ macro_rules! decl_module {
 			{ fn on_initialize( $( $param_name : $param ),* ) { $( $impl )* } }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$($rest)*
 		);
 	};
@@ -370,7 +383,8 @@ macro_rules! decl_module {
 		{}
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		fn on_initialise($($param_name:ident : $param:ty),* ) { $( $impl:tt )* }
 		$($rest:tt)*
@@ -381,42 +395,90 @@ macro_rules! decl_module {
 	};
 	(@normalize
 		$(#[$attr:meta])*
-		pub struct $mod_type:ident<$trait_instance:ident: $trait_name:ident>
+		pub struct $mod_type:ident<
+			$trait_instance:ident: $trait_name:ident
+			$(<I>, I: $instantiable:path $(= $module_default_instance:path)?)?
+		>
 		for enum $call_type:ident where origin: $origin_type:ty, system = $system:ident
 		{ $( $deposit_event:tt )* }
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		fn offchain_worker($($param_name:ident : $param:ty),* ) { $( $impl:tt )* }
 		$($rest:tt)*
 	) => {
 		$crate::decl_module!(@normalize
 			$(#[$attr])*
-			pub struct $mod_type<$trait_instance: $trait_name>
+			pub struct $mod_type<
+				$trait_instance: $trait_name$(<I>, I: $instantiable $(= $module_default_instance)?)?
+			>
 			for enum $call_type where origin: $origin_type, system = $system
 			{ $( $deposit_event )* }
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ fn offchain_worker( $( $param_name : $param ),* ) { $( $impl )* } }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$($rest)*
 		);
 	};
+
+	// This puts a constant in the parsed constants list.
+	(@normalize
+		$(#[$attr:meta])*
+		pub struct $mod_type:ident<
+			$trait_instance:ident: $trait_name:ident
+			$(<I>, $instance:ident: $instantiable:path $(= $module_default_instance:path)?)?
+		>
+		for enum $call_type:ident where origin: $origin_type:ty, system = $system:ident
+		{ $( $deposit_event:tt )* }
+		{ $( $on_initialize:tt )* }
+		{ $( $on_finalize:tt )* }
+		{ $( $offchain:tt )* }
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
+		$( #[doc = $doc_attr:tt] )*
+		const $name:ident: $ty:ty = $value:expr;
+		$( $rest:tt )*
+	) => {
+		$crate::decl_module!(@normalize
+			$(#[$attr])*
+			pub struct $mod_type<
+				$trait_instance: $trait_name
+				$( <I>, $instance: $instantiable $(= $module_default_instance)? )?
+			>
+			for enum $call_type where origin: $origin_type, system = $system
+			{ $( $deposit_event )* }
+			{ $( $on_initialize )* }
+			{ $( $on_finalize )* }
+			{ $( $offchain )* }
+			{
+				$( $constants )*
+				$( #[doc = $doc_attr ] )*
+				$name: $ty = $value;
+			}
+			[ $( $dispatchables )* ]
+			$($rest)*
+		);
+	};
+
 	// This puts the function statement into the [], decreasing `$rest` and moving toward finishing the parse.
 	(@normalize
 		$(#[$attr:meta])*
 		pub struct $mod_type:ident<
-			$trait_instance:ident:
-				$trait_name:ident$(<I>, $instance:ident: $instantiable:path $(= $module_default_instance:path)?)?
+			$trait_instance:ident: $trait_name:ident
+			$(<I>, $instance:ident: $instantiable:path $(= $module_default_instance:path)?)?
 			>
 		for enum $call_type:ident where origin: $origin_type:ty, system = $system:ident
 		{ $( $deposit_event:tt )* }
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		#[weight = $weight:expr]
 		$fn_vis:vis fn $fn_name:ident(
@@ -434,8 +496,9 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
+			{ $( $constants )* }
 			[
-				$($t)*
+				$( $dispatchables )*
 				$(#[doc = $doc_attr])*
 				#[weight = $weight]
 				$fn_vis fn $fn_name(
@@ -458,7 +521,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$fn_vis:vis fn $fn_name:ident(
 			$from:ident $(, $(#[$codec_attr:ident])* $param_name:ident : $param:ty)*
@@ -475,7 +539,8 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]
 			$(#[doc = $doc_attr])*
 			#[weight = $crate::dispatch::TransactionWeight::default()]
 			$fn_vis fn $fn_name(
@@ -493,7 +558,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$(#[weight = $weight:expr])?
 		$fn_vis:vis fn $fn_name:ident(
@@ -516,7 +582,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$(#[weight = $weight:expr])?
 		$fn_vis:vis fn $fn_name:ident(
@@ -539,7 +606,8 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 		$(#[doc = $doc_attr:tt])*
 		$(#[weight = $weight:expr])?
 		$fn_vis:vis fn $fn_name:ident(
@@ -555,7 +623,8 @@ macro_rules! decl_module {
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
-			[ $($t)* ]
+			{ $( $constants )* }
+			[ $( $dispatchables )* ]

 			$(#[doc = $doc_attr])*
 			$(#[weight = $weight])?
@@ -575,18 +644,20 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
-		[ $($t:tt)* ]
+		{ $( $constants:tt )* }
+		[ $( $dispatchables:tt )* ]
 	) => {
 		$crate::decl_module!(@imp
 			$(#[$attr])*
 			pub struct $mod_type<$trait_instance: $trait_name$(<I>, I: $instantiable $(= $module_default_instance)?)?>
 			for enum $call_type where origin: $origin_type, system = $system {
-				$($t)*
+				$( $dispatchables )*
 			}
 			{ $( $deposit_event )* }
 			{ $( $on_initialize )* }
 			{ $( $on_finalize )* }
 			{ $( $offchain )* }
+			{ $( $constants )* }
 		);
 	};

@@ -939,10 +1010,9 @@ macro_rules! decl_module {
 		{ $( $on_initialize:tt )* }
 		{ $( $on_finalize:tt )* }
 		{ $( $offchain:tt )* }
+		{ $( $constants:tt )* }
 	) => {
-		$crate::__check_reserved_fn_name! {
-			$($fn_name)*
-		}
+		$crate::__check_reserved_fn_name! { $( $fn_name )* }

 		// Workaround for https://github.com/rust-lang/rust/issues/26925 . Remove when sorted.
 		#[derive(Clone, Copy, PartialEq, Eq)]
@@ -1068,7 +1138,10 @@ macro_rules! decl_module {
 		impl<$trait_instance: $trait_name $(<I>, $instance: $instantiable)?> $crate::dispatch::fmt::Debug
 			for $call_type<$trait_instance $(, $instance)?>
 		{
-			fn fmt(&self, _f: &mut $crate::dispatch::fmt::Formatter) -> $crate::dispatch::result::Result<(), $crate::dispatch::fmt::Error> {
+			fn fmt(
+				&self,
+				_f: &mut $crate::dispatch::fmt::Formatter,
+			) -> $crate::dispatch::result::Result<(), $crate::dispatch::fmt::Error> {
 				match *self {
 					$(
 						$call_type::$fn_name( $( ref $param_name ),* ) =>
@@ -1110,7 +1183,10 @@ macro_rules! decl_module {

 		impl<$trait_instance: $trait_name $(<I>, $instance: $instantiable)?> $mod_type<$trait_instance $(, $instance)?> {
 			#[doc(hidden)]
-			pub fn dispatch<D: $crate::dispatch::Dispatchable<Trait = $trait_instance>>(d: D, origin: D::Origin) -> $crate::dispatch::Result {
+			pub fn dispatch<D: $crate::dispatch::Dispatchable<Trait = $trait_instance>>(
+				d: D,
+				origin: D::Origin,
+			) -> $crate::dispatch::Result {
 				d.dispatch(origin)
 			}
 		}
@@ -1118,6 +1194,10 @@ macro_rules! decl_module {
 			$mod_type<$trait_instance: $trait_name $(<I>, $instance: $instantiable)?> $call_type $origin_type
 			{$( $(#[doc = $doc_attr])* fn $fn_name($from $(, $(#[$codec_attr])* $param_name : $param )*); )*}
 		}
+		$crate::__impl_module_constants_metadata ! {
+			$mod_type<$trait_instance: $trait_name $(<I>, $instance: $instantiable)?>
+			$( $constants )*
+		}
 	}
 }

@@ -1191,6 +1271,115 @@ macro_rules! __dispatch_impl_metadata {
 	}
 }

+/// Implement metadata for module constants.
+#[macro_export]
+#[doc(hidden)]
+macro_rules! __impl_module_constants_metadata {
+	// Without instance
+	(
+		$mod_type:ident<$trait_instance:ident: $trait_name:ident>
+		$(
+			$( #[doc = $doc_attr:tt] )*
+			$name:ident: $type:ty = $value:expr;
+		)*
+	) => {
+		$crate::paste::item! {
+			$crate::__impl_module_constants_metadata! {
+				GENERATE_CODE
+				$mod_type<$trait_instance: $trait_name>
+				$(
+					$( #[doc = $doc_attr] )*
+					[< $name DefaultByteGetter >]
+					$name<$trait_instance: $trait_name>: $type = $value;
+				)*
+			}
+		}
+	};
+	// With instance
+	(
+		$mod_type:ident<$trait_instance:ident: $trait_name:ident<I>, $instance:ident: $instantiable:path>
+		$(
+			$( #[doc = $doc_attr:tt] )*
+			$name:ident: $type:ty = $value:expr;
+		)*
+	) => {
+		$crate::paste::item! {
+			$crate::__impl_module_constants_metadata! {
+				GENERATE_CODE
+				$mod_type<$trait_instance: $trait_name<I>, $instance: $instantiable>
+				$(
+					$( #[doc = $doc_attr] )*
+					[< $name DefaultByteGetter >]
+					$name<$trait_instance: $trait_name<I>, $instance: $instantiable>: $type = $value;
+				)*
+			}
+		}
+	};
+	// Do the code generation
+	(GENERATE_CODE
+		$mod_type:ident<$trait_instance:ident: $trait_name:ident $(<I>, $instance:ident: $instantiable:path)?>
+		$(
+			$( #[doc = $doc_attr:tt] )*
+			$default_byte_name:ident
+			$name:ident<
+				$const_trait_instance:ident: $const_trait_name:ident $(
+					<I>, $const_instance:ident: $const_instantiable:path
+				)*
+			>: $type:ty = $value:expr;
+		)*
+	) => {
+		impl<$trait_instance: 'static + $trait_name $(<I>, $instance: $instantiable)?>
+			$mod_type<$trait_instance $(, $instance)?>
+		{
+			#[doc(hidden)]
+			pub fn module_constants_metadata() -> &'static [$crate::dispatch::ModuleConstantMetadata] {
+				// Create the `ByteGetter`s
+				$(
+					#[allow(non_upper_case_types)]
+					#[allow(non_camel_case_types)]
+					struct $default_byte_name<
+						$const_trait_instance: $const_trait_name $(
+							<I>, $const_instance: $const_instantiable
+						)?
+					>($crate::dispatch::marker::PhantomData<
+						($const_trait_instance $(, $const_instance)?)
+					>);
+					impl<$const_trait_instance: 'static + $const_trait_name $(
+						<I>, $const_instance: $const_instantiable)?
+					> $crate::dispatch::DefaultByte
+						for $default_byte_name <$const_trait_instance $(, $const_instance)?>
+					{
+						fn default_byte(&self) -> $crate::dispatch::Vec<u8> {
+							let value: $type = $value;
+							$crate::dispatch::Encode::encode(&value)
+						}
+					}
+				)*
+				&[
+					$(
+						$crate::dispatch::ModuleConstantMetadata {
+							name: $crate::dispatch::DecodeDifferent::Encode(stringify!($name)),
+							ty: $crate::dispatch::DecodeDifferent::Encode(stringify!($type)),
+							value: $crate::dispatch::DecodeDifferent::Encode(
+								$crate::dispatch::DefaultByteGetter(
+									&$default_byte_name::<
+										$const_trait_instance $(, $const_instance)?
+									>(
+										$crate::dispatch::marker::PhantomData
+									)
+								)
+							),
+							documentation: $crate::dispatch::DecodeDifferent::Encode(
+								&[ $( $doc_attr ),* ]
+							),
+						}
+					),*
+				]
+			}
+		}
+	}
+}
+
 /// Convert the list of calls into their JSON representation, joined by ",".
 #[macro_export]
 #[doc(hidden)]
@@ -136,6 +136,7 @@ macro_rules! decl_event {
 		}
 		impl Event {
 			#[allow(dead_code)]
+			#[doc(hidden)]
 			pub fn metadata() -> &'static [ $crate::event::EventMetadata ] {
 				$crate::__events_to_metadata!(; $( $events )* )
 			}
@@ -242,8 +242,8 @@ mod tests {
 	use codec::Codec;
 	use runtime_io::{with_externalities, Blake2Hasher};
 	pub use srml_metadata::{
-		DecodeDifferent, StorageMetadata, StorageFunctionMetadata,
-		StorageFunctionType, StorageFunctionModifier,
+		DecodeDifferent, StorageEntryMetadata,
+		StorageEntryType, StorageEntryModifier,
 		DefaultByte, DefaultByteGetter, StorageHasher
 	};
 	pub use rstd::marker::PhantomData;
@@ -422,114 +422,112 @@ mod tests {
 		});
 	}

-	const EXPECTED_METADATA: StorageMetadata = StorageMetadata {
-		functions: DecodeDifferent::Encode(&[
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("Data"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map{
-					hasher: StorageHasher::Twox64Concat,
-					key: DecodeDifferent::Encode("u32"), value: DecodeDifferent::Encode("u64"), is_linked: true
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructData(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+	const EXPECTED_METADATA: &[StorageEntryMetadata] = &[
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("Data"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map{
+				hasher: StorageHasher::Twox64Concat,
+				key: DecodeDifferent::Encode("u32"), value: DecodeDifferent::Encode("u64"), is_linked: true
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GenericData"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map{
-					hasher: StorageHasher::Twox128,
-					key: DecodeDifferent::Encode("T::BlockNumber"),
-					value: DecodeDifferent::Encode("T::BlockNumber"),
-					is_linked: true
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGenericData(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructData(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GenericData"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map{
+				hasher: StorageHasher::Twox128,
+				key: DecodeDifferent::Encode("T::BlockNumber"),
+				value: DecodeDifferent::Encode("T::BlockNumber"),
+				is_linked: true
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GenericData2"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map{
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("T::BlockNumber"),
-					value: DecodeDifferent::Encode("T::BlockNumber"),
-					is_linked: true
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGenericData2(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGenericData(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GenericData2"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map{
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("T::BlockNumber"),
+				value: DecodeDifferent::Encode("T::BlockNumber"),
+				is_linked: true
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("DataDM"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::DoubleMap{
-					hasher: StorageHasher::Twox64Concat,
-					key1: DecodeDifferent::Encode("u32"),
-					key2: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("u64"),
-					key2_hasher: StorageHasher::Blake2_256,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructDataDM(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGenericData2(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("DataDM"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::DoubleMap{
+				hasher: StorageHasher::Twox64Concat,
+				key1: DecodeDifferent::Encode("u32"),
+				key2: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("u64"),
+				key2_hasher: StorageHasher::Blake2_256,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GenericDataDM"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::DoubleMap{
-					hasher: StorageHasher::Blake2_256,
-					key1: DecodeDifferent::Encode("T::BlockNumber"),
-					key2: DecodeDifferent::Encode("T::BlockNumber"),
-					value: DecodeDifferent::Encode("T::BlockNumber"),
-					key2_hasher: StorageHasher::Twox128,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGenericDataDM(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructDataDM(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GenericDataDM"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::DoubleMap{
+				hasher: StorageHasher::Blake2_256,
+				key1: DecodeDifferent::Encode("T::BlockNumber"),
+				key2: DecodeDifferent::Encode("T::BlockNumber"),
+				value: DecodeDifferent::Encode("T::BlockNumber"),
+				key2_hasher: StorageHasher::Twox128,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GenericData2DM"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::DoubleMap{
-					hasher: StorageHasher::Blake2_256,
-					key1: DecodeDifferent::Encode("T::BlockNumber"),
-					key2: DecodeDifferent::Encode("T::BlockNumber"),
-					value: DecodeDifferent::Encode("T::BlockNumber"),
-					key2_hasher: StorageHasher::Twox256,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGenericData2DM(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGenericDataDM(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GenericData2DM"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::DoubleMap{
+				hasher: StorageHasher::Blake2_256,
+				key1: DecodeDifferent::Encode("T::BlockNumber"),
+				key2: DecodeDifferent::Encode("T::BlockNumber"),
+				value: DecodeDifferent::Encode("T::BlockNumber"),
+				key2_hasher: StorageHasher::Twox256,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("AppendableDM"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::DoubleMap{
-					hasher: StorageHasher::Blake2_256,
-					key1: DecodeDifferent::Encode("u32"),
-					key2: DecodeDifferent::Encode("T::BlockNumber"),
-					value: DecodeDifferent::Encode("Vec<u32>"),
-					key2_hasher: StorageHasher::Blake2_256,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGenericData2DM(PhantomData::<Test>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGenericData2DM(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("AppendableDM"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::DoubleMap{
+				hasher: StorageHasher::Blake2_256,
+				key1: DecodeDifferent::Encode("u32"),
+				key2: DecodeDifferent::Encode("T::BlockNumber"),
+				value: DecodeDifferent::Encode("Vec<u32>"),
+				key2_hasher: StorageHasher::Blake2_256,
 			},
-		])
-	};
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGenericData2DM(PhantomData::<Test>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+	];

 	#[test]
 	fn store_metadata() {
-		let metadata = Module::<Test>::store_metadata();
+		let metadata = Module::<Test>::store_metadata_functions();
 		assert_eq!(EXPECTED_METADATA, metadata);
 	}
 }
@@ -15,15 +15,11 @@
 // along with Substrate.  If not, see <http://www.gnu.org/licenses/>.

 pub use srml_metadata::{
-	DecodeDifferent, FnEncode, RuntimeMetadata,
-	ModuleMetadata, RuntimeMetadataV5,
-	DefaultByteGetter, RuntimeMetadataPrefixed,
-	StorageMetadata, StorageFunctionMetadata,
-	StorageFunctionType, StorageFunctionModifier,
-	DefaultByte, StorageHasher
+	DecodeDifferent, FnEncode, RuntimeMetadata, ModuleMetadata, RuntimeMetadataV6,
+	DefaultByteGetter, RuntimeMetadataPrefixed, StorageEntryMetadata,
+	StorageEntryType, StorageEntryModifier, DefaultByte, StorageHasher
 };

-
 /// Implements the metadata support for the given runtime and all its modules.
 ///
 /// Example:
@@ -40,8 +36,8 @@ macro_rules! impl_runtime_metadata {
 	) => {
 		impl $runtime {
 			pub fn metadata() -> $crate::metadata::RuntimeMetadataPrefixed {
-				$crate::metadata::RuntimeMetadata::V5 (
-					$crate::metadata::RuntimeMetadataV5 {
+				$crate::metadata::RuntimeMetadata::V6 (
+					$crate::metadata::RuntimeMetadataV6 {
 						modules: $crate::__runtime_modules_to_metadata!($runtime;; $( $rest )*),
 					}
 				).into()
@@ -67,6 +63,11 @@ macro_rules! __runtime_modules_to_metadata {
 				storage: $crate::__runtime_modules_to_metadata_calls_storage!($mod, $module $( <$instance> )?, $runtime, $(with $kw)*),
 				calls: $crate::__runtime_modules_to_metadata_calls_call!($mod, $module $( <$instance> )?, $runtime, $(with $kw)*),
 				event: $crate::__runtime_modules_to_metadata_calls_event!($mod, $module $( <$instance> )?, $runtime, $(with $kw)*),
+				constants: $crate::metadata::DecodeDifferent::Encode(
+					$crate::metadata::FnEncode(
+						$mod::$module::<$runtime $(, $mod::$instance )?>::module_constants_metadata
+					)
+				)
 			};
 			$( $rest )*
 		)
@@ -227,23 +228,31 @@ macro_rules! __runtime_modules_to_metadata_calls_storage {
 mod tests {
 	use super::*;
 	use srml_metadata::{
-		EventMetadata,
-		StorageFunctionModifier, StorageFunctionType, FunctionMetadata,
-		StorageFunctionMetadata,
-		ModuleMetadata, RuntimeMetadataPrefixed
+		EventMetadata, StorageEntryModifier, StorageEntryType, FunctionMetadata, StorageEntryMetadata,
+		ModuleMetadata, RuntimeMetadataPrefixed, DefaultByte, ModuleConstantMetadata, DefaultByteGetter,
 	};
-	use crate::codec::{Encode, Decode};
+	use codec::{Encode, Decode};
+	use crate::traits::Get;

 	mod system {
+		use super::*;
+
 		pub trait Trait {
+			const ASSOCIATED_CONST: u64 = 500;
 			type Origin: Into<Result<RawOrigin<Self::AccountId>, Self::Origin>>
 				+ From<RawOrigin<Self::AccountId>>;
-			type AccountId;
-			type BlockNumber;
+			type AccountId: From<u32> + Encode;
+			type BlockNumber: From<u32> + Encode;
+			type SomeValue: Get<u32>;
 		}

 		decl_module! {
-			pub struct Module<T: Trait> for enum Call where origin: T::Origin {}
+			pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+				/// Hi, I am a comment.
+				const BlockNumber: T::BlockNumber = 100.into();
+				const GetType: T::AccountId = T::SomeValue::get().into();
+				const ASSOCIATED_CONST: u64 = T::ASSOCIATED_CONST.into();
+			}
 		}

 		decl_event!(
@@ -359,10 +368,15 @@ mod tests {
 		type BlockNumber = u32;
 	}

+	crate::parameter_types! {
+		pub const SystemValue: u32 = 600;
+	}
+
 	impl system::Trait for TestRuntime {
 		type Origin = Origin;
 		type AccountId = u32;
 		type BlockNumber = u32;
+		type SomeValue = SystemValue;
 	}

 	impl_runtime_metadata!(
@@ -372,76 +386,130 @@ mod tests {
 			event_module2::Module with Event Storage Call,
 	);

-	const EXPECTED_METADATA: RuntimeMetadata = RuntimeMetadata::V5(
-		RuntimeMetadataV5 {
-		modules: DecodeDifferent::Encode(&[
-			ModuleMetadata {
-				name: DecodeDifferent::Encode("system"),
-				prefix: DecodeDifferent::Encode(FnEncode(||"")),
-				storage: None,
-				calls: None,
-				event: Some(DecodeDifferent::Encode(
-			 		FnEncode(||&[
-						EventMetadata {
-							name: DecodeDifferent::Encode("SystemEvent"),
-							arguments: DecodeDifferent::Encode(&[]),
-							documentation: DecodeDifferent::Encode(&[])
-						}
-			 		])
-				)),
-			},
-			ModuleMetadata {
-				name: DecodeDifferent::Encode("event_module"),
-				prefix: DecodeDifferent::Encode(FnEncode(||"")),
-				storage: None,
-				calls: Some(
-					DecodeDifferent::Encode(FnEncode(||&[
-						FunctionMetadata {
-							name: DecodeDifferent::Encode("aux_0"),
-							arguments: DecodeDifferent::Encode(&[]),
-							documentation: DecodeDifferent::Encode(&[]),
-						}
-					]))),
-				event: Some(DecodeDifferent::Encode(
-			 		FnEncode(||&[
-						EventMetadata {
-							name: DecodeDifferent::Encode("TestEvent"),
-							arguments: DecodeDifferent::Encode(&["Balance"]),
-							documentation: DecodeDifferent::Encode(&[" Hi, I am a comment."])
-						}
-			 		])
-				)),
-			},
-			ModuleMetadata {
-				name: DecodeDifferent::Encode("event_module2"),
-				prefix: DecodeDifferent::Encode(FnEncode(||"TestStorage")),
-				storage: Some(DecodeDifferent::Encode(
-			 		FnEncode(||&[
-						StorageFunctionMetadata {
-							name: DecodeDifferent::Encode("StorageMethod"),
-							modifier: StorageFunctionModifier::Optional,
-							ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-							default: DecodeDifferent::Encode(
-								DefaultByteGetter(
-									&event_module2::__GetByteStructStorageMethod(::std::marker::PhantomData::<TestRuntime>)
-								)
-							),
-							documentation: DecodeDifferent::Encode(&[]),
-						}
-			 		])
-				)),
-				calls: Some(DecodeDifferent::Encode(FnEncode(||&[	]))),
-				event: Some(DecodeDifferent::Encode(
-			 		FnEncode(||&[
-						EventMetadata {
-							name: DecodeDifferent::Encode("TestEvent"),
-							arguments: DecodeDifferent::Encode(&["Balance"]),
-							documentation: DecodeDifferent::Encode(&[])
-						}
-			 		])
-				)),
-			},
-		])}
+	struct ConstantBlockNumberByteGetter;
+	impl DefaultByte for ConstantBlockNumberByteGetter {
+		fn default_byte(&self) -> Vec<u8> {
+			100u32.encode()
+		}
+	}
+
+	struct ConstantGetTypeByteGetter;
+	impl DefaultByte for ConstantGetTypeByteGetter {
+		fn default_byte(&self) -> Vec<u8> {
+			SystemValue::get().encode()
+		}
+	}
+
+	struct ConstantAssociatedConstByteGetter;
+	impl DefaultByte for ConstantAssociatedConstByteGetter {
+		fn default_byte(&self) -> Vec<u8> {
+			<TestRuntime as system::Trait>::ASSOCIATED_CONST.encode()
+		}
+	}
+
+	const EXPECTED_METADATA: RuntimeMetadata = RuntimeMetadata::V6(
+		RuntimeMetadataV6 {
+			modules: DecodeDifferent::Encode(&[
+				ModuleMetadata {
+					name: DecodeDifferent::Encode("system"),
+					prefix: DecodeDifferent::Encode(FnEncode(|| "")),
+					storage: None,
+					calls: None,
+					event: Some(DecodeDifferent::Encode(
+						FnEncode(||&[
+							EventMetadata {
+								name: DecodeDifferent::Encode("SystemEvent"),
+								arguments: DecodeDifferent::Encode(&[]),
+								documentation: DecodeDifferent::Encode(&[])
+							}
+						])
+					)),
+					constants: DecodeDifferent::Encode(
+						FnEncode(|| &[
+							ModuleConstantMetadata {
+								name: DecodeDifferent::Encode("BlockNumber"),
+								ty: DecodeDifferent::Encode("T::BlockNumber"),
+								value: DecodeDifferent::Encode(
+									DefaultByteGetter(&ConstantBlockNumberByteGetter)
+								),
+								documentation: DecodeDifferent::Encode(&[" Hi, I am a comment."]),
+							},
+							ModuleConstantMetadata {
+								name: DecodeDifferent::Encode("GetType"),
+								ty: DecodeDifferent::Encode("T::AccountId"),
+								value: DecodeDifferent::Encode(
+									DefaultByteGetter(&ConstantGetTypeByteGetter)
+								),
+								documentation: DecodeDifferent::Encode(&[]),
+							},
+							ModuleConstantMetadata {
+								name: DecodeDifferent::Encode("ASSOCIATED_CONST"),
+								ty: DecodeDifferent::Encode("u64"),
+								value: DecodeDifferent::Encode(
+									DefaultByteGetter(&ConstantAssociatedConstByteGetter)
+								),
+								documentation: DecodeDifferent::Encode(&[]),
+							}
+						])
+					),
+				},
+				ModuleMetadata {
+					name: DecodeDifferent::Encode("event_module"),
+					prefix: DecodeDifferent::Encode(FnEncode(|| "")),
+					storage: None,
+					calls: Some(
+						DecodeDifferent::Encode(FnEncode(|| &[
+							FunctionMetadata {
+								name: DecodeDifferent::Encode("aux_0"),
+								arguments: DecodeDifferent::Encode(&[]),
+								documentation: DecodeDifferent::Encode(&[]),
+							}
+						]))),
+					event: Some(DecodeDifferent::Encode(
+						FnEncode(||&[
+							EventMetadata {
+								name: DecodeDifferent::Encode("TestEvent"),
+								arguments: DecodeDifferent::Encode(&["Balance"]),
+								documentation: DecodeDifferent::Encode(&[" Hi, I am a comment."])
+							}
+						])
+					)),
+					constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				},
+				ModuleMetadata {
+					name: DecodeDifferent::Encode("event_module2"),
+					prefix: DecodeDifferent::Encode(FnEncode(||"TestStorage")),
+					storage: Some(DecodeDifferent::Encode(
+						FnEncode(||&[
+							StorageEntryMetadata {
+								name: DecodeDifferent::Encode("StorageMethod"),
+								modifier: StorageEntryModifier::Optional,
+								ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+								default: DecodeDifferent::Encode(
+									DefaultByteGetter(
+										&event_module2::__GetByteStructStorageMethod(
+											std::marker::PhantomData::<TestRuntime>
+										)
+									)
+								),
+								documentation: DecodeDifferent::Encode(&[]),
+							}
+						])
+					)),
+					calls: Some(DecodeDifferent::Encode(FnEncode(|| &[]))),
+					event: Some(DecodeDifferent::Encode(
+						FnEncode(||&[
+							EventMetadata {
+								name: DecodeDifferent::Encode("TestEvent"),
+								arguments: DecodeDifferent::Encode(&["Balance"]),
+								documentation: DecodeDifferent::Encode(&[])
+							}
+						])
+					)),
+					constants: DecodeDifferent::Encode(FnEncode(|| &[])),
+				},
+			])
+		}
 	);

 	#[test]
@@ -450,6 +518,6 @@ mod tests {
 		let metadata_decoded = RuntimeMetadataPrefixed::decode(&mut &metadata_encoded[..]);
 		let expected_metadata: RuntimeMetadataPrefixed = EXPECTED_METADATA.into();

-		assert_eq!(expected_metadata, metadata_decoded.unwrap());
+		pretty_assertions::assert_eq!(expected_metadata, metadata_decoded.unwrap());
 	}
 }
@@ -390,327 +390,325 @@ mod tests {
 		type BlockNumber = u32;
 	}

-	const EXPECTED_METADATA: StorageMetadata = StorageMetadata {
-		functions: DecodeDifferent::Encode(&[
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("U32"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[ " Hello, this is doc!" ]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBU32"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("U32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBU32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETU32"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("T::Origin")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETU32"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETU32WITHCONFIG"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETU32WITHCONFIG(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETU32WITHCONFIG"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIG(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETU32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETU32MYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETU32WITHCONFIGMYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETU32WITHCONFIGMYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETU32WITHCONFIGMYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIGMYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETU32WITHCONFIGMYDEFOPT"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("u32")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIGMYDEFOPT(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
+	const EXPECTED_METADATA: &[StorageEntryMetadata] = &[
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("U32"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[ " Hello, this is doc!" ]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBU32"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("U32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBU32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETU32"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("T::Origin")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETU32"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETU32WITHCONFIG"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETU32WITHCONFIG(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETU32WITHCONFIG"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIG(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETU32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETU32MYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETU32WITHCONFIGMYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETU32WITHCONFIGMYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETU32WITHCONFIGMYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIGMYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETU32WITHCONFIGMYDEFOPT"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("u32")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETU32WITHCONFIGMYDEFOPT(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},

-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("MAPU32"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("MAPU32"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBMAPU32"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBMAPU32"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("MAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("MAPU32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBMAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBMAPU32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETMAPU32"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETMAPU32"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETMAPU32"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETMAPU32"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETMAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETMAPU32MYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETMAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: false,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETMAPU32MYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: false,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("LINKEDMAPU32"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: true,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructLINKEDMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("LINKEDMAPU32"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: true,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBLINKEDMAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Optional,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: true,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBLINKEDMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructLINKEDMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBLINKEDMAPU32MYDEF"),
+			modifier: StorageEntryModifier::Optional,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: true,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("GETLINKEDMAPU32"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: true,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructGETLINKEDMAPU32(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBLINKEDMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("GETLINKEDMAPU32"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: true,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("PUBGETLINKEDMAPU32MYDEF"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Map {
-					hasher: StorageHasher::Blake2_256,
-					key: DecodeDifferent::Encode("u32"),
-					value: DecodeDifferent::Encode("String"),
-					is_linked: true,
-				},
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructPUBGETLINKEDMAPU32MYDEF(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructGETLINKEDMAPU32(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("PUBGETLINKEDMAPU32MYDEF"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Map {
+				hasher: StorageHasher::Blake2_256,
+				key: DecodeDifferent::Encode("u32"),
+				value: DecodeDifferent::Encode("String"),
+				is_linked: true,
 			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("COMPLEXTYPE1"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("::std::vec::Vec<<T as Trait>::Origin>")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructCOMPLEXTYPE1(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("COMPLEXTYPE2"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("(Vec<Vec<(u16, Box<()>)>>, u32)")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructCOMPLEXTYPE2(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-			StorageFunctionMetadata {
-				name: DecodeDifferent::Encode("COMPLEXTYPE3"),
-				modifier: StorageFunctionModifier::Default,
-				ty: StorageFunctionType::Plain(DecodeDifferent::Encode("([u32; 25])")),
-				default: DecodeDifferent::Encode(
-					DefaultByteGetter(&__GetByteStructCOMPLEXTYPE3(PhantomData::<TraitImpl>))
-				),
-				documentation: DecodeDifferent::Encode(&[]),
-			},
-		])
-	};
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructPUBGETLINKEDMAPU32MYDEF(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("COMPLEXTYPE1"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("::std::vec::Vec<<T as Trait>::Origin>")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructCOMPLEXTYPE1(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("COMPLEXTYPE2"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("(Vec<Vec<(u16, Box<()>)>>, u32)")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructCOMPLEXTYPE2(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+		StorageEntryMetadata {
+			name: DecodeDifferent::Encode("COMPLEXTYPE3"),
+			modifier: StorageEntryModifier::Default,
+			ty: StorageEntryType::Plain(DecodeDifferent::Encode("([u32; 25])")),
+			default: DecodeDifferent::Encode(
+				DefaultByteGetter(&__GetByteStructCOMPLEXTYPE3(PhantomData::<TraitImpl>))
+			),
+			documentation: DecodeDifferent::Encode(&[]),
+		},
+	];

 	#[test]
 	fn store_metadata() {
-		let metadata = Module::<TraitImpl>::store_metadata();
+		let metadata = Module::<TraitImpl>::store_metadata_functions();
 		assert_eq!(EXPECTED_METADATA, metadata);
 	}

@@ -17,7 +17,7 @@

 use runtime_io::{with_externalities, Blake2Hasher};
 use srml_support::{
-	Parameter,
+	Parameter, traits::Get, parameter_types,
 	runtime_primitives::{generic, BuildStorage, traits::{BlakeTwo256, Block as _, Verify}},
 };
 use inherents::{
@@ -40,10 +40,13 @@ mod module1 {
 	pub trait Trait<I>: system::Trait {
 		type Event: From<Event<Self, I>> + Into<<Self as system::Trait>::Event>;
 		type Origin: From<Origin<Self, I>>;
+		type SomeParameter: Get<u32>;
 	}

 	srml_support::decl_module! {
 		pub struct Module<T: Trait<I>, I: InstantiableThing> for enum Call where origin: <T as system::Trait>::Origin {
+			fn offchain_worker() {}
+
 			fn deposit_event<T, I>() = default;

 			fn one() {
@@ -165,13 +168,19 @@ mod module3 {
 	}
 }

+parameter_types! {
+	pub const SomeValue: u32 = 100;
+}
+
 impl module1::Trait<module1::Instance1> for Runtime {
 	type Event = Event;
 	type Origin = Origin;
+	type SomeParameter = SomeValue;
 }
 impl module1::Trait<module1::Instance2> for Runtime {
 	type Event = Event;
 	type Origin = Origin;
+	type SomeParameter = SomeValue;
 }
 impl module2::Trait for Runtime {
 	type Amount = u16;