ohno 0.3.5

High-quality Rust error handling.
Documentation 
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// Copyright (c) Microsoft Corporation.
// Licensed under the MIT License.

//! Tests for adding context to errors.

use ohno::{AppError, EnrichableExt, IntoAppError, app_err, enrich_err};

#[test]
fn enrich_err_ext_simple() {
    let err = app_err!("connection failed").enrich("database operation");
    let msg = err.to_string();
    let lines: Vec<_> = msg.lines().collect();
    assert_eq!(lines[0], "connection failed");
    assert!(lines[1].starts_with("> database operation"), "{msg}");
    assert!(lines[1].contains(file!()), "{msg}");
}

#[test]
fn enrich_err_ext_with() {
    let user_id = 123;
    let err = app_err!("not found").enrich_with(|| format!("failed to load user {user_id}"));
    let msg = err.to_string();
    let lines: Vec<_> = msg.lines().collect();
    assert_eq!(lines[0], "not found");
    assert!(lines[1].starts_with("> failed to load user 123"), "{msg}");
    assert!(lines[1].contains(file!()), "{msg}");
}

#[test]
fn enrich_err_ext_multiple_layers() {
    let base = app_err!("timeout");
    let ctx1 = base.enrich("http request");
    let ctx2 = ctx1.enrich_with(|| "api call");
    let msg = ctx2.to_string();
    let lines: Vec<_> = msg.lines().collect();
    assert_eq!(lines[0], "timeout");
    assert!(lines[1].starts_with("> http request"), "{msg}");
    assert!(lines[1].contains(file!()), "{msg}");
    assert!(lines[2].starts_with("> api call"), "{msg}");
    assert!(lines[2].contains(file!()), "{msg}");
}

#[test]
fn enrich_err_on_result() {
    fn fail() -> Result<i32, AppError> {
        Err(app_err!("operation failed"))
    }

    let err = fail().into_app_err("additional context").unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("operation failed"));
    assert!(msg.contains("additional context"));
}

#[test]
fn enrich_err_macro_with_simple_message() {
    #[enrich_err("failed to process request")]
    fn fail() -> Result<i32, AppError> {
        Err(app_err!("invalid input"))
    }

    let err = fail().unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("invalid input"));
    assert!(msg.contains("failed to process request"));
    assert!(msg.contains(file!()), "{msg}");
}

#[test]
fn enrich_err_macro_with_format_args() {
    #[enrich_err("failed to parse value: {}", value)]
    fn parse_value(value: &str) -> Result<i32, AppError> {
        value.parse::<i32>().map_err(|e| app_err!("parse error: {}", e))
    }

    assert_eq!(parse_value("42").unwrap(), 42);

    let err = parse_value("abc").unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("parse error"));
    assert!(msg.contains("failed to parse value: abc"));
}

#[test]
fn enrich_err_macro_with_multiple_params() {
    #[enrich_err("operation {} failed for user {}", op_name, user_id)]
    fn perform_operation(op_name: &str, user_id: i32, should_fail: bool) -> Result<(), AppError> {
        if should_fail {
            return Err(app_err!("internal error"));
        }
        Ok(())
    }

    perform_operation("save", 123, false).unwrap();

    let err = perform_operation("delete", 456, true).unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("internal error"));
    assert!(msg.contains("operation delete failed for user 456"));
}

#[test]
fn enrich_err_macro_default_message() {
    #[enrich_err]
    fn some_operation(should_fail: bool) -> Result<i32, AppError> {
        if should_fail {
            return Err(app_err!("something went wrong"));
        }
        Ok(100)
    }

    assert_eq!(some_operation(false).unwrap(), 100);

    let err = some_operation(true).unwrap_err();
    let msg = err.to_string();
    assert!(msg.contains("something went wrong"));
    assert!(msg.contains("error in function some_operation"));
}