Migrate custom error trait impls to thiserror
#1856
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core/src/events.rs
Outdated
| @@ -376,7 +376,8 @@ impl<T: Config> EventDetails<T> { | |||
| .map(|f| scale_decode::Field::new(f.ty.id, f.name.as_deref())); | |||
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| let decoded = | |||
| scale_value::scale::decode_as_fields(bytes, &mut fields, self.metadata.types())?; | |||
| scale_value::scale::decode_as_fields(bytes, &mut fields, self.metadata.types()) | |||
| .map_err(Into::<scale_decode::Error>::into)?; | |||
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I'm curious what has changed that makes these new .map_errs necessary?
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decode_as_fields returns DecodeError and although scale_decode::Error implements From<DecodeError> compiler needs an explicit cast
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I don't get why that would be the case though offhand, when it wasn't before? Also, out of interest, can you use Into::into or do you need the explicit type there too?
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No idea either.
Fails to infer the type without explicit annotation
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I had a look and there was a missing From impl for scale_decode::visitor::DecodeError (confusingly similar name!); adding that let the Into's go away :)
Co-authored-by: Niklas Adolfsson <niklasadolfsson1@gmail.com>
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Looks good to me.
Would be good if you could double-check whether we should use #[error(transparent)] from every wrapped error type to avoid duplicate stuff in the display impl.
Such Decode error: Decode error <some message> but I'm not sure I could be wrong :P
| @@ -5,14 +5,15 @@ | |||
| //! A Polkadot-JS account loader. | |||
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| use base64::Engine; | |||
| use core::fmt::Display; | |||
| use crypto_secretbox::{ | |||
| aead::{Aead, KeyInit}, | |||
| Key, Nonce, XSalsa20Poly1305, | |||
| }; | |||
| use serde::Deserialize; | |||
| use subxt_core::utils::AccountId32; | |||
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| // TODO: when `codec::Error` implements `core::Error` | ||
| // remove this impl and replace it by thiserror #[from] | ||
| impl From<codec::Error> for Error { | ||
| fn from(err: codec::Error) -> Error { | ||
| Error::Codec(err) | ||
| } | ||
| } |
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Why does not implementing core::Error stop you from using #[from] here?
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error[E0599]: the method `as_dyn_error` exists for reference `&Error`, but its trait bounds were not satisfied
--> core/src/error.rs:17:13
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17 | Codec(#[from] codec::Error),
| ^^^^ method cannot be called on `&Error` due to unsatisfied trait bounds
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::: /home/niklasad1/.cargo/registry/src/index.crates.io-6f17d22bba15001f/parity-scale-codec-3.6.12/src/error.rs:26:1
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26 | pub struct Error {
| ---------------- doesn't satisfy `parity_scale_codec::Error: AsDynError<'_>` or `parity_scale_codec::Error: StdError`
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= note: the following trait bounds were not satisfied:
`parity_scale_codec::Error: StdError`
which is required by `parity_scale_codec::Error: AsDynError<'_>`
`&parity_scale_codec::Error: StdError`
which is required by `&parity_scale_codec::Error: AsDynError<'_>`It's probably because codec::Error/no_std doesn't implement core::error::Error/StdError and thus the from impl bounds isn't satisfied.
| impl From<bip39::Error> for Error { | ||
| fn from(err: bip39::Error) -> Self { | ||
| Error::Phrase(err) | ||
| } | ||
| } |
| Error::Hex(e) => write!(f, "Cannot parse hex string: {e}"), | ||
| } | ||
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| impl From<hex::FromHexError> for Error { |
| Error::Hex(e) => write!(f, "Cannot parse hex string: {e}"), | ||
| Error::Signature(e) => write!(f, "Signature error: {e}"), | ||
| } | ||
| impl From<schnorrkel::SignatureError> for Error { |
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Use #[from] instead of the below manual From impls?
Description
Migrates Error trait impls to
thiserroras it now supports nostd