add support for integrating with fern

Author: iamcodemaker

README.md

@@ -94,3 +94,4 @@ shall be dual licensed as above, without any additional terms or conditions.
 ## See Also
 
 - [`wasm-bindgen-console-logger`](https://github.com/blm768/wasm-bindgen-console-logger)
+- [`fern`](https://github.com/daboross/fern) (use with `console_log::log`)

src/lib.rs

@@ -28,6 +28,12 @@
 //! | `warn!()`  | `console.warn()`  |
 //! | `error!()` | `console.error()` |
 //! 
+//! # Getting Fancy
+//!
+//! The feature set provided by this crate is intentionally very basic. If you need more flexible
+//! formatting of log messages (timestamps, file and line info, etc.) this crate can be used with
+//! the [`fern`] logger via the [`console_log::log`] function.
+//!
 //! # Code Size
 //! 
 //! [Twiggy] reports this library adding about 180Kb to the size of a minimal wasm binary in a
@@ -74,6 +80,8 @@
 //! the shims generated by `wasm-bindgen`, not the location of the logger call.
 //!
 //! [Twiggy]: https://github.com/rustwasm/twiggy
+//! [`console_log::log`]: fn.log.html
+//! [`fern`]: https://docs.rs/fern
 
 use log::{Log, Level, Record, Metadata, SetLoggerError};
 use web_sys::console;
@@ -92,21 +100,36 @@ impl Log for WebConsoleLogger {
             return;
         }
 
-        // pick the console.log() variant for the appropriate logging level
-        let console_log = match record.level() {
-            Level::Error => console::error_1,
-            Level::Warn => console::warn_1,
-            Level::Info => console::info_1,
-            Level::Debug => console::log_1,
-            Level::Trace => console::debug_1,
-        };
-
-        console_log(&format!("{}", record.args()).into());
+        log(record);
     }
 
     fn flush(&self) {}
 }
 
+/// Print a `log::Record` to the browser's console at the appropriate level.
+///
+/// This function is useful for integrating with the [`fern`](https://crates.io/crates/fern) logger
+/// crate.
+///
+/// ## Example
+/// ```rust,ignore
+/// fern::Dispatch::new()
+///     .chain(fern::Output::call(console_log::log))
+///     .apply()?;
+/// ```
+pub fn log(record: &Record) {
+    // pick the console.log() variant for the appropriate logging level
+    let console_log = match record.level() {
+        Level::Error => console::error_1,
+        Level::Warn => console::warn_1,
+        Level::Info => console::info_1,
+        Level::Debug => console::log_1,
+        Level::Trace => console::debug_1,
+    };
+
+    console_log(&format!("{}", record.args()).into());
+}
+
 /// Initializes the global logger setting `max_log_level` to the given value.
 ///
 /// ## Example