11 unstable releases (3 breaking)
0.4.4 | Oct 20, 2021 |
---|---|
0.4.3 | Sep 27, 2021 |
0.4.2 | Aug 3, 2021 |
0.4.1 | Jul 26, 2021 |
0.1.1 | May 27, 2021 |
#133 in Rust patterns
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Used in 281 crates
(27 directly)
40KB
677 lines
flex-error
flex-error
is a lightweight Rust library that uses macros and traits to switch between different error tracing implementations and no_std. The library currently supports 3 modes via Cargo feature flags: eyre_tracer
(default), anyhow_tracer
, and string_tracer
(no_std).
The library separates out several concepts as traits: ErrorDetail
, ErrorTrace
, and ErrorSource
.
- The
ErrorDetail
is responsible to structured metadata information about a specific error. - The
ErrorTracer
is responsible for tracing error chains and backtraces. - The
ErrorSource
allows generic conversion of external error types into an ErrorDetail with optional ErrorTrace. - An application error is of type
ErrorReport<ErrorDetail, ErrorTracer>
, which holds both the error details and trace.
With the separation of concerns, flex-error
allows applications to easily switch between different error reporting implementations, such as eyre
and anyhow
, by implementing ErrorTracer
for the respective reporters.
flex-error
defines a define_error!
macro that define custom Detail
types and error types as alias to ErrorReport<Detail, DefaultTracer>
. The DefaultTracer
type is set globally by the feature flag, so that application error types do not have to be over-generalized. The trade off is that it is not possible to use multiple ErrorTracer
implementations at the same time across different crates that use flex-error
.
Demo
The flex-error-demo-full directory contains a demo program that reports error using eyre
. When run with RUST_BACKTRACE=1
, it should produce something like follows:
$ RUST_BACKTRACE=1 cargo run flex-error-demo-full
Error:
0: error caused by foo: Foo has failed
1: system error
2: error1
Location:
flex-error/flex-error/src/tracer_impl/eyre.rs:25
---------------------------------- BACKTRACE -----------------------------------
⋮ 5 frames hidden ⋮
6: flex_error::tracer_impl::eyre::<impl flex_error::tracer::ErrorTracer<E> for eyre::Report>::new_trace::h471dd777954521dc
at flex-error/flex-error/src/tracer_impl/eyre.rs:25
7: flex_error::tracer::<impl flex_error::source::ErrorSource<Tracer> for flex_error::source::StdError<E>>::error_details::hba2719390b7121af
at flex-error/flex-error/src/tracer.rs:26
8: flex_error::report::ErrorReport<Detail,Trace>::trace_from::h39963733bcaf4442
at flex-error/flex-error/src/report.rs:32
9: flex_error_demo_full::foo::system_error::h9d131e83ad96a9bb
at flex-error/flex-error/src/macros.rs:111
10: flex_error_demo_full::main::hb0f615a97c840949
at flex-error/flex-error-demo-full/src/main.rs:50
License
Copyright © 2021 Informal Systems
Licensed under the Apache License, Version 2.0 (the "License"); you may not use the files in this repository except in compliance with the License. You may obtain a copy of the License at
https://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software distributed under the License is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the License for the specific language governing permissions and limitations under the License.
Dependencies
~75KB