From 323e6771829df243077f3d02301a3a281e4e02da Mon Sep 17 00:00:00 2001
From: Niko Matsakis <niko@alum.mit.edu>
Date: Sun, 7 Aug 2022 03:01:39 -0400
Subject: [PATCH] enable logging of salsa events by default

and add logging to tests
---
 components/salsa-2022/src/database.rs | 7 +++++--
 salsa-2022-tests/Cargo.toml           | 3 ++-
 salsa-2022-tests/tests/hello_world.rs | 1 +
 3 files changed, 8 insertions(+), 3 deletions(-)

diff --git a/components/salsa-2022/src/database.rs b/components/salsa-2022/src/database.rs
index fd6b1b72..c6077f45 100644
--- a/components/salsa-2022/src/database.rs
+++ b/components/salsa-2022/src/database.rs
@@ -1,11 +1,14 @@
-use crate::{storage::HasJarsDyn, Event, Runtime};
+use crate::{storage::HasJarsDyn, DebugWithDb, Event, Runtime};
 
 pub trait Database: HasJarsDyn + AsSalsaDatabase {
     /// This function is invoked at key points in the salsa
     /// runtime. It permits the database to be customized and to
     /// inject logging or other custom behavior.
+    ///
+    /// By default, the event is logged at level debug using
+    /// the standard `log` facade.
     fn salsa_event(&self, event_fn: Event) {
-        #![allow(unused_variables)]
+        log::debug!("salsa_event: {:?}", event_fn.debug(self));
     }
 
     fn salsa_runtime(&self) -> &Runtime;
diff --git a/salsa-2022-tests/Cargo.toml b/salsa-2022-tests/Cargo.toml
index edd31a4e..d703b211 100644
--- a/salsa-2022-tests/Cargo.toml
+++ b/salsa-2022-tests/Cargo.toml
@@ -9,4 +9,5 @@ edition = "2021"
 salsa = { path = "../components/salsa-2022", package = "salsa-2022" }
 expect-test = "1.4.0"
 parking_lot = "0.12.1"
-
+test-log = "0.2.11"
+env_logger = "*"
diff --git a/salsa-2022-tests/tests/hello_world.rs b/salsa-2022-tests/tests/hello_world.rs
index 1c03a822..c12ea5de 100644
--- a/salsa-2022-tests/tests/hello_world.rs
+++ b/salsa-2022-tests/tests/hello_world.rs
@@ -5,6 +5,7 @@
 use salsa_2022_tests::{HasLogger, Logger};
 
 use expect_test::expect;
+use test_log::test;
 
 #[salsa::jar(db = Db)]
 struct Jar(MyInput, MyTracked, final_result, intermediate_result);