Allow Substrate Pallet to be Initialized via Dipatchable (#481)

* Add dispatchable for intializing pallet

* Add Polkadot JS types for Substrate bridge pallet

* Ensure Root is the only one that can initialize the pallet

* Add some tests

* Pack initialization data into struct

* Only allow pallet to be initialized once

* Use new initialization config in nodes

* Rename ScheduledChange in Ethereum pallet

We're renaming it to prevent clashes with Substrate bridge pallet type
of the same name. This is relevant when importing types to Polkadot JS
Apps.

* Move all Polkadot JS types into one file

* Appease Clippy

bridges/modules/ethereum/src/lib.rs

@@ -120,7 +120,7 @@ pub struct ValidatorsSet {
 /// Validators set change as it is stored in the runtime storage.
 #[derive(Encode, Decode, PartialEq, RuntimeDebug)]
 #[cfg_attr(test, derive(Clone))]
-pub struct ScheduledChange {
+pub struct AuraScheduledChange {
 	/// Validators of this set.
 	pub validators: Vec<Address>,
 	/// Hash of the block which has emitted previous validators change signal.
@@ -187,7 +187,7 @@ pub struct ImportContext<Submitter> {
 	parent_hash: H256,
 	parent_header: AuraHeader,
 	parent_total_difficulty: U256,
-	parent_scheduled_change: Option<ScheduledChange>,
+	parent_scheduled_change: Option<AuraScheduledChange>,
 	validators_set_id: u64,
 	validators_set: ValidatorsSet,
 	last_signal_block: Option<HeaderId>,
@@ -210,7 +210,7 @@ impl<Submitter> ImportContext<Submitter> {
 	}
 
 	/// Returns the validator set change if the parent header has signaled a change.
-	pub fn parent_scheduled_change(&self) -> Option<&ScheduledChange> {
+	pub fn parent_scheduled_change(&self) -> Option<&AuraScheduledChange> {
 		self.parent_scheduled_change.as_ref()
 	}
 
@@ -293,7 +293,7 @@ pub trait Storage {
 	) -> Option<ImportContext<Self::Submitter>>;
 	/// Get new validators that are scheduled by given header and hash of the previous
 	/// block that has scheduled change.
-	fn scheduled_change(&self, hash: &H256) -> Option<ScheduledChange>;
+	fn scheduled_change(&self, hash: &H256) -> Option<AuraScheduledChange>;
 	/// Insert imported header.
 	fn insert_header(&mut self, header: HeaderToImport<Self::Submitter>);
 	/// Finalize given block and schedules pruning of all headers
@@ -479,7 +479,7 @@ decl_storage! {
 		/// When it reaches zero, we are free to prune validator set as well.
 		ValidatorsSetsRc: map hasher(twox_64_concat) u64 => Option<u64>;
 		/// Map of validators set changes scheduled by given header.
-		ScheduledChanges: map hasher(identity) H256 => Option<ScheduledChange>;
+		ScheduledChanges: map hasher(identity) H256 => Option<AuraScheduledChange>;
 	}
 	add_extra_genesis {
 		config(initial_header): AuraHeader;
@@ -766,7 +766,7 @@ impl<T: Trait<I>, I: Instance> Storage for BridgeStorage<T, I> {
 		})
 	}
 
-	fn scheduled_change(&self, hash: &H256) -> Option<ScheduledChange> {
+	fn scheduled_change(&self, hash: &H256) -> Option<AuraScheduledChange> {
 		ScheduledChanges::<I>::get(hash)
 	}
 
@@ -777,7 +777,7 @@ impl<T: Trait<I>, I: Instance> Storage for BridgeStorage<T, I> {
 		if let Some(scheduled_change) = header.scheduled_change {
 			ScheduledChanges::<I>::insert(
 				&header.id.hash,
-				ScheduledChange {
+				AuraScheduledChange {
 					validators: scheduled_change,
 					prev_signal_block: header.context.last_signal_block,
 				},
@@ -1119,7 +1119,7 @@ pub(crate) mod tests {
 					if i == 7 && j == 1 {
 						ScheduledChanges::<DefaultInstance>::insert(
 							hash,
-							ScheduledChange {
+							AuraScheduledChange {
 								validators: validators_addresses(5),
 								prev_signal_block: None,
 							},

bridges/modules/ethereum/src/validators.rs

@@ -277,7 +277,7 @@ pub(crate) mod tests {
 	use super::*;
 	use crate::mock::{run_test, validators_addresses, validators_change_receipt, TestRuntime};
 	use crate::DefaultInstance;
-	use crate::{BridgeStorage, Headers, ScheduledChange, ScheduledChanges, StoredHeader};
+	use crate::{AuraScheduledChange, BridgeStorage, Headers, ScheduledChanges, StoredHeader};
 	use bp_eth_poa::compute_merkle_root;
 	use frame_support::StorageMap;
 
@@ -428,7 +428,7 @@ pub(crate) mod tests {
 				next_validators_set_id: 0,
 				last_signal_block: scheduled_at,
 			};
-			let scheduled_change = ScheduledChange {
+			let scheduled_change = AuraScheduledChange {
 				validators: validators_addresses(1),
 				prev_signal_block: None,
 			};

bridges/modules/ethereum/src/verification.rs

@@ -16,7 +16,7 @@
 
 use crate::error::Error;
 use crate::validators::{Validators, ValidatorsConfiguration};
-use crate::{AuraConfiguration, ChainTime, ImportContext, PoolConfiguration, ScheduledChange, Storage};
+use crate::{AuraConfiguration, AuraScheduledChange, ChainTime, ImportContext, PoolConfiguration, Storage};
 use bp_eth_poa::{
 	public_to_address, step_validator, Address, AuraHeader, HeaderId, Receipt, SealedEmptyStep, H256, H520, U128, U256,
 };
@@ -341,7 +341,7 @@ fn find_next_validators_signal<S: Storage>(storage: &S, context: &ImportContext<
 	// if parent schedules validators set change, then it may be our set
 	// else we'll start with last known change
 	let mut current_set_signal_block = context.last_signal_block();
-	let mut next_scheduled_set: Option<ScheduledChange> = None;
+	let mut next_scheduled_set: Option<AuraScheduledChange> = None;
 
 	loop {
 		// if we have reached block that signals finalized change, then
@@ -456,7 +456,7 @@ mod tests {
 			});
 			ScheduledChanges::<DefaultInstance>::insert(
 				header.header.parent_hash,
-				ScheduledChange {
+				AuraScheduledChange {
 					validators: signalled_set,
 					prev_signal_block: None,
 				},