Crate anyhow_auto_context 

anyhow-auto-context

Automatic context for anyhow errors based on scope and location.

Usage

With Option

use anyhow_auto_context::auto_context;

fn main() -> anyhow::Result<()> {
    let expected_some = None;
    auto_context!(expected_some)
}

$ cargo run --example option
Error: expected_some in option::main at examples/option.rs:6:5

With Result

use anyhow::Result;
use anyhow_auto_context::auto_context;

fn main() -> Result<()> {
    auto_context!(foo())
}

fn foo() -> Result<()> {
    auto_context!(bar())
}

fn bar() -> Result<()> {
    anyhow::bail!("my error")
}

$ cargo run --example result
Error: foo() in result::main at examples/result.rs:6:5

Caused by:
    0: bar() in result::foo at examples/result.rs:10:5
    1: my error

With additional context

The optional context arguments follow format! semantics and are evaluated only on the error path.

use anyhow::Result;
use anyhow_auto_context::auto_context;

fn main() -> Result<()> {
    for i in 1..100 {
        auto_context!(not_42(i), "i = {i}")?;
    }
    Ok(())
}

fn not_42(n: usize) -> Result<()> {
    anyhow::ensure!(n != 42, "Unexpected 42");
    Ok(())
}

$ cargo run --example context
Error: not_42(i) in context::main at examples/context.rs:7:9 with i = 42

Caused by:
    Unexpected 42

Contributing

• please run .pre-commit.sh before sending a PR, it will check everything

License

This project is licensed under the MIT license.

Macros

auto_context

Adds automatic anyhow context based on scope and location.