Custom RPC for Merkle Mountain Range pallet (#8137)

* Add MMR custom RPC.

* Change RuntimeApi to avoid hardcoding leaf type.

* Properly implement the new RuntimeAPI and wire up RPC.

* Extract Offchain DB as separate execution extension.

* Enable offchain DB access for offchain calls.

* Fix offchain_election tests.

* Skip block initialisation for proof generation.

* Fix integration test setup.

* Fix offchain tests. Not sure how I missed them earlier 🤷.

* Fix long line.

* One more test missing.

* Update mock for multi-phase.

* Address review grumbbles.

* Address review grumbles.

* Fix line width of a comment

substrate/primitives/runtime/src/offchain/http.rs

@@ -518,7 +518,7 @@ mod tests {
 	use super::*;
 	use sp_io::TestExternalities;
 	use sp_core::offchain::{
-		OffchainExt,
+		OffchainWorkerExt,
 		testing,
 	};
 
@@ -526,7 +526,7 @@ mod tests {
 	fn should_send_a_basic_request_and_get_response() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let request: Request = Request::get("http://localhost:1234");
@@ -567,7 +567,7 @@ mod tests {
 	fn should_send_a_post_request() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let pending = Request::default()

substrate/primitives/runtime/src/offchain/storage.rs

@@ -104,7 +104,7 @@ mod tests {
 	use super::*;
 	use sp_io::TestExternalities;
 	use sp_core::offchain::{
-		OffchainExt,
+		OffchainDbExt,
 		testing,
 	};
 
@@ -112,7 +112,7 @@ mod tests {
 	fn should_set_and_get() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain));
 
 		t.execute_with(|| {
 			let val = StorageValue::persistent(b"testval");
@@ -134,7 +134,7 @@ mod tests {
 	fn should_mutate() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain));
 
 		t.execute_with(|| {
 			let val = StorageValue::persistent(b"testval");

substrate/primitives/runtime/src/offchain/storage_lock.rs

@@ -453,7 +453,7 @@ pub trait BlockNumberProvider {
 #[cfg(test)]
 mod tests {
 	use super::*;
-	use sp_core::offchain::{testing, OffchainExt};
+	use sp_core::offchain::{testing, OffchainWorkerExt, OffchainDbExt};
 	use sp_io::TestExternalities;
 
 	const VAL_1: u32 = 0u32;
@@ -463,7 +463,8 @@ mod tests {
 	fn storage_lock_write_unlock_lock_read_unlock() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain.clone()));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let mut lock = StorageLock::<'_, Time>::new(b"lock_1");
@@ -493,7 +494,8 @@ mod tests {
 	fn storage_lock_and_forget() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain.clone()));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let mut lock = StorageLock::<'_, Time>::new(b"lock_2");
@@ -517,7 +519,8 @@ mod tests {
 	fn storage_lock_and_let_expire_and_lock_again() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain.clone()));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let sleep_until = offchain::timestamp().add(Duration::from_millis(500));
@@ -549,7 +552,8 @@ mod tests {
 	fn extend_active_lock() {
 		let (offchain, state) = testing::TestOffchainExt::new();
 		let mut t = TestExternalities::default();
-		t.register_extension(OffchainExt::new(offchain));
+		t.register_extension(OffchainDbExt::new(offchain.clone()));
+		t.register_extension(OffchainWorkerExt::new(offchain));
 
 		t.execute_with(|| {
 			let lock_expiration = Duration::from_millis(300);