Add an dbg! equivalent to gloo-console (#158)

* console dbg!

* fix name

* fmt

crates/console/src/console_dbg.rs

@@ -0,0 +1,23 @@
+/// A macro similar to [`dbg!`].
+///
+/// See the [stdlib documentation][std::dbg] to learn more. This macro calls `console.log`
+/// instead of `eprintln!`
+#[macro_export]
+macro_rules! console {
+    () => {
+        $crate::log!(::std::format!("[{}:{}]", ::std::file!(), ::std::line!()));
+    };
+    ($val:expr $(,)?) => {
+        // Use of `match` here is intentional because it affects the lifetimes
+        // of temporaries - https://stackoverflow.com/a/48732525/1063961
+        match $val {
+            tmp => {
+                $crate::log!(::std::format!("[{}:{}] {} =", ::std::file!(), ::std::line!(), ::std::stringify!($val)), &tmp);
+                tmp
+            }
+        }
+    };
+    ($($val:expr),+ $(,)?) => {
+        ($($crate::dbg!($val)),+,)
+    };
+}

crates/console/src/lib.rs

@@ -17,6 +17,7 @@
 
 #![deny(missing_docs, missing_debug_implementations)]
 
+mod console_dbg;
 mod counter;
 #[doc(hidden)]
 pub mod externs;