More decl_error! migrations (#4427)

* Update assets to `decl_error`

* Update aura to `decl_error`

* Update authority discovery to `decl_error`

* Update collective to `decl_error`

* Update evm to `decl_error!`

* Fix error with replace

* Revert "Update authority discovery to `decl_error`"

This reverts commit 26e8f3c56656963d847e984c6f2c8e1f88014899.

* Revert "Update aura to `decl_error`"

This reverts commit 8f17c44ca8375a4a755710aaab7ad4d9522c4376.

* Update democracy to `decl_error`

* Update finality-tracker to `decl_error`

* Update grandpa to `decl_error`

* `assert` to `ensure` in dispatchable function

substrate/frame/finality-tracker/src/lib.rs

@@ -19,9 +19,9 @@
 #![cfg_attr(not(feature = "std"), no_std)]
 
 use sp_inherents::{InherentIdentifier, ProvideInherent, InherentData, MakeFatalError};
-use sp_runtime::traits::{One, Zero, SaturatedConversion};
+use sp_runtime::traits::{One, Zero, SaturatedConversion, ModuleDispatchError};
 use sp_std::{prelude::*, result, cmp, vec};
-use frame_support::{decl_module, decl_storage};
+use frame_support::{decl_module, decl_storage, decl_error, ensure};
 use frame_support::traits::Get;
 use frame_system::{ensure_none, Trait as SystemTrait};
 use sp_finality_tracker::{INHERENT_IDENTIFIER, FinalizedInherentData};
@@ -56,8 +56,18 @@ decl_storage! {
 	}
 }
 
+decl_error! {
+	pub enum Error {
+		/// Final hint must be updated only once in the block
+		AlreadyUpdated,
+		/// Finalized height above block number
+		BadHint,
+	}
+}
+
 decl_module! {
 	pub struct Module<T: Trait> for enum Call where origin: T::Origin {
+		type Error = Error;
 		/// The number of recent samples to keep from this chain. Default is 101.
 		const WindowSize: T::BlockNumber = T::WindowSize::get();
 
@@ -67,11 +77,11 @@ decl_module! {
 		/// Hint that the author of this block thinks the best finalized
 		/// block is the given number.
 		fn final_hint(origin, #[compact] hint: T::BlockNumber) {
-			ensure_none(origin)?;
-			assert!(!<Self as Store>::Update::exists(), "Final hint must be updated only once in the block");
-			assert!(
+			ensure_none(origin).map_err(|e| e.as_str())?;
+			ensure!(!<Self as Store>::Update::exists(), Error::AlreadyUpdated);
+			ensure!(
 				frame_system::Module::<T>::block_number() >= hint,
-				"Finalized height above block number",
+				Error::BadHint,
 			);
 			<Self as Store>::Update::put(hint);
 		}