BREAKING - Try-runtime: Use proper error types (#13993)

* Try-state: DispatchResult as return type

* try_state for the rest of the pallets

* pre_upgrade

* post_upgrade

* try_runtime_upgrade

* fixes

* bags-list fix

* fix

* update test

* warning fix

* ...

* final fixes 🤞

* warning..

* frame-support

* warnings

* Update frame/staking/src/migrations.rs

Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>

* fix

* fix warning

* nit fix

* merge fixes

* small fix

* should be good now

* missed these ones

* introduce TryRuntimeError and TryRuntimeResult

* fixes

* fix

* removed TryRuntimeResult & made some fixes

* fix testsg

* tests passing

* unnecessary imports

* Update frame/assets/src/migration.rs

Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>

---------

Co-authored-by: Liam Aharon <liam.aharon@hotmail.com>
Co-authored-by: Keith Yeung <kungfukeith11@gmail.com>

substrate/frame/election-provider-multi-phase/src/lib.rs

@@ -257,6 +257,9 @@ use sp_runtime::{
 };
 use sp_std::prelude::*;
 
+#[cfg(feature = "try-runtime")]
+use sp_runtime::TryRuntimeError;
+
 #[cfg(feature = "runtime-benchmarks")]
 mod benchmarking;
 #[cfg(test)]
@@ -883,7 +886,7 @@ pub mod pallet {
 		}
 
 		#[cfg(feature = "try-runtime")]
-		fn try_state(_n: T::BlockNumber) -> Result<(), &'static str> {
+		fn try_state(_n: T::BlockNumber) -> Result<(), TryRuntimeError> {
 			Self::do_try_state()
 		}
 	}
@@ -1579,7 +1582,7 @@ impl<T: Config> Pallet<T> {
 
 #[cfg(feature = "try-runtime")]
 impl<T: Config> Pallet<T> {
-	fn do_try_state() -> Result<(), &'static str> {
+	fn do_try_state() -> Result<(), TryRuntimeError> {
 		Self::try_state_snapshot()?;
 		Self::try_state_signed_submissions_map()?;
 		Self::try_state_phase_off()
@@ -1588,7 +1591,7 @@ impl<T: Config> Pallet<T> {
 	// [`Snapshot`] state check. Invariants:
 	// - [`DesiredTargets`] exists if and only if [`Snapshot`] is present.
 	// - [`SnapshotMetadata`] exist if and only if [`Snapshot`] is present.
-	fn try_state_snapshot() -> Result<(), &'static str> {
+	fn try_state_snapshot() -> Result<(), TryRuntimeError> {
 		if <Snapshot<T>>::exists() &&
 			<SnapshotMetadata<T>>::exists() &&
 			<DesiredTargets<T>>::exists()
@@ -1600,7 +1603,7 @@ impl<T: Config> Pallet<T> {
 		{
 			Ok(())
 		} else {
-			Err("If snapshot exists, metadata and desired targets should be set too. Otherwise, none should be set.")
+			Err("If snapshot exists, metadata and desired targets should be set too. Otherwise, none should be set.".into())
 		}
 	}
 
@@ -1608,28 +1611,34 @@ impl<T: Config> Pallet<T> {
 	// - All [`SignedSubmissionIndices`] are present in [`SignedSubmissionsMap`], and no more;
 	// - [`SignedSubmissionNextIndex`] is not present in [`SignedSubmissionsMap`];
 	// - [`SignedSubmissionIndices`] is sorted by election score.
-	fn try_state_signed_submissions_map() -> Result<(), &'static str> {
+	fn try_state_signed_submissions_map() -> Result<(), TryRuntimeError> {
 		let mut last_score: ElectionScore = Default::default();
 		let indices = <SignedSubmissionIndices<T>>::get();
 
 		for (i, indice) in indices.iter().enumerate() {
 			let submission = <SignedSubmissionsMap<T>>::get(indice.2);
 			if submission.is_none() {
-				return Err("All signed submissions indices must be part of the submissions map")
+				return Err(
+					"All signed submissions indices must be part of the submissions map".into()
+				)
 			}
 
 			if i == 0 {
 				last_score = indice.0
 			} else {
 				if last_score.strict_threshold_better(indice.0, Perbill::zero()) {
-					return Err("Signed submission indices vector must be ordered by election score")
+					return Err(
+						"Signed submission indices vector must be ordered by election score".into()
+					)
 				}
 				last_score = indice.0;
 			}
 		}
 
 		if <SignedSubmissionsMap<T>>::iter().nth(indices.len()).is_some() {
-			return Err("Signed submissions map length should be the same as the indices vec length")
+			return Err(
+				"Signed submissions map length should be the same as the indices vec length".into()
+			)
 		}
 
 		match <SignedSubmissionNextIndex<T>>::get() {
@@ -1637,7 +1646,8 @@ impl<T: Config> Pallet<T> {
 			next =>
 				if <SignedSubmissionsMap<T>>::get(next).is_some() {
 					return Err(
-						"The next submissions index should not be in the submissions maps already",
+						"The next submissions index should not be in the submissions maps already"
+							.into(),
 					)
 				} else {
 					Ok(())
@@ -1647,12 +1657,12 @@ impl<T: Config> Pallet<T> {
 
 	// [`Phase::Off`] state check. Invariants:
 	// - If phase is `Phase::Off`, [`Snapshot`] must be none.
-	fn try_state_phase_off() -> Result<(), &'static str> {
+	fn try_state_phase_off() -> Result<(), TryRuntimeError> {
 		match Self::current_phase().is_off() {
 			false => Ok(()),
 			true =>
 				if <Snapshot<T>>::get().is_some() {
-					Err("Snapshot must be none when in Phase::Off")
+					Err("Snapshot must be none when in Phase::Off".into())
 				} else {
 					Ok(())
 				},