From f98477913292e5de63621578964502772bcf7dca Mon Sep 17 00:00:00 2001
From: Bryan Chen <xlchen1291@gmail.com>
Date: Tue, 5 Oct 2021 21:20:12 +1300
Subject: [PATCH] implement dispatch_as

---
 bin/node/runtime/src/lib.rs  |  3 ++-
 frame/contracts/src/tests.rs |  1 +
 frame/proxy/src/tests.rs     |  1 +
 frame/utility/src/lib.rs     | 39 ++++++++++++++++++++++++++++++++++++
 4 files changed, 43 insertions(+), 1 deletion(-)

diff --git a/bin/node/runtime/src/lib.rs b/bin/node/runtime/src/lib.rs
index b115087d514d0..5919d510d5f3a 100644
--- a/bin/node/runtime/src/lib.rs
+++ b/bin/node/runtime/src/lib.rs
@@ -222,8 +222,9 @@ impl frame_system::Config for Runtime {
 impl pallet_randomness_collective_flip::Config for Runtime {}
 
 impl pallet_utility::Config for Runtime {
-	type Event = Event;
+type Event = Event;
 	type Call = Call;
+	type PalletsOrigin = OriginCaller;
 	type WeightInfo = pallet_utility::weights::SubstrateWeight<Runtime>;
 }
 
diff --git a/frame/contracts/src/tests.rs b/frame/contracts/src/tests.rs
index b2141ca18b0b1..1fde2c338093a 100644
--- a/frame/contracts/src/tests.rs
+++ b/frame/contracts/src/tests.rs
@@ -244,6 +244,7 @@ impl pallet_timestamp::Config for Test {
 impl pallet_utility::Config for Test {
 	type Event = Event;
 	type Call = Call;
+	type PalletsOrigin = OriginCaller;
 	type WeightInfo = ();
 }
 parameter_types! {
diff --git a/frame/proxy/src/tests.rs b/frame/proxy/src/tests.rs
index d319ebb1a5ab0..c38d3de03b90f 100644
--- a/frame/proxy/src/tests.rs
+++ b/frame/proxy/src/tests.rs
@@ -96,6 +96,7 @@ impl pallet_balances::Config for Test {
 impl pallet_utility::Config for Test {
 	type Event = Event;
 	type Call = Call;
+	type PalletsOrigin = OriginCaller;
 	type WeightInfo = ();
 }
 parameter_types! {
diff --git a/frame/utility/src/lib.rs b/frame/utility/src/lib.rs
index 54de87c4740c8..88d9048f63541 100644
--- a/frame/utility/src/lib.rs
+++ b/frame/utility/src/lib.rs
@@ -96,6 +96,9 @@ pub mod pallet {
 			+ IsSubType<Call<Self>>
 			+ IsType<<Self as frame_system::Config>::Call>;
 
+		/// The caller origin, overarching type of all pallets origins.
+		type PalletsOrigin: Parameter + Into<<Self as frame_system::Config>::Origin>;
+
 		/// Weight information for extrinsics in this pallet.
 		type WeightInfo: WeightInfo;
 	}
@@ -110,6 +113,8 @@ pub mod pallet {
 		BatchCompleted,
 		/// A single item within a Batch of dispatches has completed with no error.
 		ItemCompleted,
+		/// A call was dispatched. \[result\]
+		DsipatchAsDone(DispatchResult),
 	}
 
 	#[pallet::extra_constants]
@@ -323,6 +328,40 @@ pub mod pallet {
 			let base_weight = T::WeightInfo::batch_all(calls_len as u32);
 			Ok(Some(base_weight + weight).into())
 		}
+
+		/// Dispatches a function call with a provided origin.
+		///
+		/// The dispatch origin for this call must be _Root_.
+		///
+		/// # <weight>
+		/// - O(1).
+		/// - Limited storage reads.
+		/// - One DB write (event).
+		/// - Weight of derivative `call` execution + 10,000.
+		/// # </weight>
+		#[pallet::weight({
+			let dispatch_info = call.get_dispatch_info();
+			(
+				dispatch_info.weight
+					.saturating_add(10_000)
+					// AccountData for inner call origin accountdata.
+					.saturating_add(T::DbWeight::get().reads_writes(1, 1)),
+				dispatch_info.class,
+			)
+		})]
+		pub fn dispatch_as(
+			origin: OriginFor<T>,
+			as_origin: T::PalletsOrigin,
+			call: Box<<T as Config>::Call>,
+		) -> DispatchResult {
+			ensure_root(origin)?;
+
+			let res = call.dispatch_bypass_filter(as_origin.into());
+
+			Self::deposit_event(Event::DsipatchAsDone(res.map(|_| ()).map_err(|e| e.error)));
+			// Sudo user does not pay a fee.
+			Ok(())
+		}
 	}
 }