chore/error: remove from str conversion and add deprecation notificat… (#7472)

* chore/error: remove from str conversion and add deprecation notifications

* fixup changes

* fix test looking for gone ::Msg variant

* another test fix

* one is duplicate, the other is not, so duplicates reported are n-1

* darn spaces

Co-authored-by: Andronik Ordian <write@reusable.software>

* remove pointless doc comments of error variants without any value

* low hanging fruits (for a tall person)

* moar error type variants

* avoid the storage modules for now

They are in need of a refactor, and the pain is rather large
removing all String error and DefaultError occurences.

* chore remove pointless error generic

* fix test for mocks, add a bunch of non_exhaustive

* max line width

* test fixes due to error changes

* fin

* error outputs... again

* undo stderr adjustments

* Update client/consensus/slots/src/lib.rs

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* remove closure clutter

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* more error types

* introduce ApiError

* extract Mock error

* ApiError refactor

* even more error types

* the last for now

* chore unused deps

* another extraction

* reduce should panic, due to extended error messages

* error test happiness

* shift error lines by one

* doc tests

* white space

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* Into -> From

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* remove pointless codec

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

* avoid pointless self import

Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

Co-authored-by: Bernhard Schuster <bernhard@parity.io>
Co-authored-by: Andronik Ordian <write@reusable.software>
Co-authored-by: Bastian Köcher <bkchr@users.noreply.github.com>

substrate/primitives/api/test/tests/decl_and_impl.rs

@@ -17,6 +17,7 @@
 
 use sp_api::{
 	RuntimeApiInfo, decl_runtime_apis, impl_runtime_apis, mock_impl_runtime_apis,
+	ApiError,
 	ApiExt,
 };
 use sp_runtime::{traits::{GetNodeBlockType, Block as BlockT}, generic::BlockId};
@@ -103,17 +104,27 @@ mock_impl_runtime_apis! {
 		}
 
 		#[advanced]
-		fn same_name(_: &BlockId<Block>) -> std::result::Result<NativeOrEncoded<()>, String> {
+		fn same_name(_: &BlockId<Block>) ->
+			std::result::Result<
+				NativeOrEncoded<()>,
+				ApiError
+			>
+		{
 			Ok(().into())
 		}
 
 		#[advanced]
-		fn wild_card(at: &BlockId<Block>, _: u32) -> std::result::Result<NativeOrEncoded<()>, String> {
+		fn wild_card(at: &BlockId<Block>, _: u32) ->
+			std::result::Result<
+				NativeOrEncoded<()>,
+				ApiError
+			>
+		{
 			if let BlockId::Number(1337) = at {
 				// yeah
 				Ok(().into())
 			} else {
-				Err("Ohh noooo".into())
+				Err(ApiError::new("MockApi", codec::Error::from("Ohh noooo")))
 			}
 		}
 	}
@@ -197,5 +208,8 @@ fn mock_runtime_api_works_with_advanced() {
 
 	Api::<Block>::same_name(&mock, &BlockId::Number(0)).unwrap();
 	mock.wild_card(&BlockId::Number(1337), 1).unwrap();
-	assert_eq!(String::from("Ohh noooo"), mock.wild_card(&BlockId::Number(1336), 1).unwrap_err());
+	assert_eq!(
+		ApiError::new("MockApi", ::codec::Error::from("Ohh noooo")),
+		mock.wild_card(&BlockId::Number(1336), 1).unwrap_err()
+	);
 }

substrate/primitives/api/test/tests/ui/mock_advanced_block_id_by_value.rs

@@ -1,4 +1,5 @@
 use substrate_test_runtime_client::runtime::Block;
+use sp_api::ApiError;
 
 sp_api::decl_runtime_apis! {
 	pub trait Api {
@@ -11,7 +12,7 @@ struct MockApi;
 sp_api::mock_impl_runtime_apis! {
 	impl Api<Block> for MockApi {
 		#[advanced]
-		fn test(&self, _: BlockId<Block>) -> Result<sp_core::NativeOrEncoded<()>, String> {
+		fn test(&self, _: BlockId<Block>) -> Result<sp_core::NativeOrEncoded<()>, ApiError> {
 			Ok(().into())
 		}
 	}

substrate/primitives/api/test/tests/ui/mock_advanced_block_id_by_value.stderr

@@ -1,13 +1,13 @@
 error: `BlockId` needs to be taken by reference and not by value!
-  --> $DIR/mock_advanced_block_id_by_value.rs:11:1
+  --> $DIR/mock_advanced_block_id_by_value.rs:12:1
    |
-11 | / sp_api::mock_impl_runtime_apis! {
-12 | |     impl Api<Block> for MockApi {
-13 | |         #[advanced]
-14 | |         fn test(&self, _: BlockId<Block>) -> Result<sp_core::NativeOrEncoded<()>, String> {
+12 | / sp_api::mock_impl_runtime_apis! {
+13 | |     impl Api<Block> for MockApi {
+14 | |         #[advanced]
+15 | |         fn test(&self, _: BlockId<Block>) -> Result<sp_core::NativeOrEncoded<()>, ApiError> {
 ...  |
-17 | |     }
-18 | | }
+18 | |     }
+19 | | }
    | |_^
    |
    = note: this error originates in a macro (in Nightly builds, run with -Z macro-backtrace for more info)

substrate/primitives/api/test/tests/ui/mock_advanced_missing_blockid.rs

@@ -1,4 +1,5 @@
 use substrate_test_runtime_client::runtime::Block;
+use sp_api::ApiError;
 
 sp_api::decl_runtime_apis! {
 	pub trait Api {
@@ -11,7 +12,7 @@ struct MockApi;
 sp_api::mock_impl_runtime_apis! {
 	impl Api<Block> for MockApi {
 		#[advanced]
-		fn test(&self) -> Result<sp_core::NativeOrEncoded<()>, String> {
+		fn test(&self) -> Result<sp_core::NativeOrEncoded<()>, ApiError> {
 			Ok(().into())
 		}
 	}

substrate/primitives/api/test/tests/ui/mock_advanced_missing_blockid.stderr

@@ -1,5 +1,5 @@
 error: If using the `advanced` attribute, it is required that the function takes at least one argument, the `BlockId`.
-  --> $DIR/mock_advanced_missing_blockid.rs:14:3
+  --> $DIR/mock_advanced_missing_blockid.rs:15:3
    |
-14 |         fn test(&self) -> Result<sp_core::NativeOrEncoded<()>, String> {
+15 |         fn test(&self) -> Result<sp_core::NativeOrEncoded<()>, ApiError> {
    |         ^^

substrate/primitives/api/test/tests/ui/mock_only_one_error_type.stderr

@@ -10,16 +10,16 @@ error: First error type was declared here.
 17 |         type Error = u32;
    |                      ^^^
 
-error[E0277]: the trait bound `u32: std::convert::From<std::string::String>` is not satisfied
+error[E0277]: the trait bound `u32: std::convert::From<sp_api_hidden_includes_DECL_RUNTIME_APIS::sp_api::ApiError>` is not satisfied
    --> $DIR/mock_only_one_error_type.rs:17:16
     |
 17  |         type Error = u32;
-    |                      ^^^ the trait `std::convert::From<std::string::String>` is not implemented for `u32`
+    |                      ^^^ the trait `std::convert::From<sp_api_hidden_includes_DECL_RUNTIME_APIS::sp_api::ApiError>` is not implemented for `u32`
     |
    ::: $WORKSPACE/primitives/api/src/lib.rs
     |
-    |     type Error: std::fmt::Debug + From<String>;
-    |                                   ------------ required by this bound in `sp_api_hidden_includes_DECL_RUNTIME_APIS::sp_api::ApiErrorExt`
+    |     type Error: std::fmt::Debug + From<ApiError>;
+    |                                   -------------- required by this bound in `sp_api_hidden_includes_DECL_RUNTIME_APIS::sp_api::ApiErrorExt`
     |
     = help: the following implementations were found:
               <u32 as std::convert::From<bool>>