logwise 0.5.1

an opinionated logging library for Rust
Documentation 
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// SPDX-License-Identifier: MIT OR Apache-2.0
use crate::log_record::LogRecord;
use crate::logger::Logger;

/**
A reference logger that logs to stderr.
 */
#[derive(Debug, Clone)]
pub struct StdErrorLogger {}

// ============================================================================
// BOILERPLATE TRAIT IMPLEMENTATIONS
// ============================================================================
//
// Design decisions for StdErrorLogger trait implementations:
//
// - Debug/Clone: Already derived - appropriate for zero-sized struct
// - Copy: Implemented - safe for zero-sized struct with no heap allocation
// - PartialEq/Eq: Implemented - all instances are equivalent (zero-sized)
// - Hash: Implemented - consistent with Eq, enables use as hash map keys
// - Default: Implemented - provides convenient zero-argument constructor
// - Display: NOT implemented - no meaningful string representation for stderr logger
// - From/Into: NOT implemented - no obvious conversions
// - Send/Sync: Automatically implemented - zero-sized struct is always thread-safe

impl Copy for StdErrorLogger {}

impl PartialEq for StdErrorLogger {
    fn eq(&self, _other: &Self) -> bool {
        // All instances of a zero-sized struct are equal
        true
    }
}

impl Eq for StdErrorLogger {}

impl std::hash::Hash for StdErrorLogger {
    fn hash<H: std::hash::Hasher>(&self, _state: &mut H) {
        // Zero-sized struct has no data to hash - this is consistent with Eq
    }
}

impl Default for StdErrorLogger {
    fn default() -> Self {
        Self::new()
    }
}

impl StdErrorLogger {
    pub const fn new() -> Self {
        Self {}
    }
}

impl Logger for StdErrorLogger {
    fn finish_log_record(&self, record: LogRecord) {
        #[cfg(not(target_arch = "wasm32"))]
        {
            use std::io::Write;
            let mut lock = std::io::stderr().lock();
            for part in record.parts {
                lock.write_all(part.as_bytes())
                    .expect("Can't log to stderr");
            }
            lock.write_all(b"\n").expect("Can't log to stderr");
        }
        #[cfg(target_arch = "wasm32")]
        {
            use crate::Level;
            let msg = record.parts.join("");
            match record.level() {
                Level::Trace => {
                    web_sys::console::trace_1(&msg.into());
                }
                Level::DebugInternal => {
                    web_sys::console::debug_1(&msg.into());
                }
                Level::Info => {
                    web_sys::console::info_1(&msg.into());
                }
                Level::Analytics => {
                    web_sys::console::info_1(&msg.into());
                }
                Level::PerfWarn => {
                    web_sys::console::warn_1(&msg.into());
                }
                Level::Warning => {
                    web_sys::console::warn_1(&msg.into());
                }
                Level::Error => {
                    if msg == "DEBUGME" {
                        panic!("DEBUGME")
                    }
                    web_sys::console::error_1(&msg.into());
                }
                Level::Panic => {
                    web_sys::console::error_1(&msg.into());
                }
                Level::Mandatory => {
                    web_sys::console::log_1(&msg.into());
                }
                Level::Profile => {
                    web_sys::console::log_1(&msg.into());
                }
            }
        }
    }

    fn finish_log_record_async<'s>(
        &'s self,
        record: LogRecord,
    ) -> std::pin::Pin<Box<dyn std::future::Future<Output = ()> + Send + 's>> {
        Box::pin(async move {
            //todo: this locks, which is maybe not what we want?
            self.finish_log_record(record)
        })
    }

    fn prepare_to_die(&self) {
        //nothing to do since we are unbuffered
    }
}