Crate tracing_unwrap

Expand description

This crate provides .unwrap_or_log() and .expect_or_log() methods on Result and Option types that log failed unwraps to a tracing::Subscriber. This is useful when, for example, you are logging to syslog or a database, and you want your unwrap failures to show up there instead of being printed to stderr.

Its API aims to mirror Rust’s std — see all the supported methods below. Failed unwraps are logged at a level of ERROR.

§Usage

Add the following to your Cargo.toml:

tracing-unwrap = "1.0"

Next, bring the ResultExt and/or OptionExt traits into scope, and make use of the new logging methods.

use tracing_unwrap::ResultExt;

tracing_subscriber::fmt().init();
let not_great: Result<(), _> = Result::Err("not terrible");

// Logs the failed unwrap and panics
not_great.unwrap_or_log();

§Methods

`std` method	`tracing-unwrap` form	trait
`Result::ok()`	`Result::ok_or_log()`	`ResultExt`
`Result::unwrap()`	`Result::unwrap_or_log()`	`ResultExt`
`Result::expect(msg)`	`Result::expect_or_log(msg)`	`ResultExt`
`Result::unwrap_err()`	`Result::unwrap_err_or_log()`	`ResultExt`
`Result::expect_err(msg)`	`Result::expect_err_or_log(msg)`	`ResultExt`
`Option::unwrap()`	`Option::unwrap_or_log()`	`OptionExt`
`Option::expect(msg)`	`Option::expect_or_log(msg)`	`OptionExt`
`Option::unwrap_none()`^†	`Option::unwrap_none_or_log()`	`OptionExt`
`Option::expect_none(msg)`^†	`Option::expect_none_or_log(msg)`	`OptionExt`

†: no longer in std, see rust-lang/rust#62633

§Features

panic-quiet: causes failed unwraps to panic with an empty message.
This feature is enabled by default — if you’d like the unwrap error message to also show in the panic message, disable default features in your Cargo.toml as follows:
tracing-unwrap = { version = "1.0", default-features = false }
log-location: calls std::panic::Location::caller() to determine the location of a failed unwrap.

Traits§

OptionExt: Extension trait for Option types.
ResultExt: Extension trait for Result types.