From b3b6a92145380ebe685bd2410db32fdee4a97e9b Mon Sep 17 00:00:00 2001
From: Nick Mathewson <nickm@torproject.org>
Date: Tue, 7 Dec 2021 19:52:49 -0500
Subject: [PATCH] Add a few tests to tor-config.

---
 Cargo.lock                       | 24 +++++++++++++++++
 crates/tor-config/Cargo.toml     |  1 +
 crates/tor-config/src/lib.rs     | 24 ++++++++++++++++-
 crates/tor-config/src/mut_cfg.rs | 45 ++++++++++++++++++++++++++++++++
 crates/tor-dirmgr/src/lib.rs     |  5 ++--
 5 files changed, 95 insertions(+), 4 deletions(-)

diff --git a/Cargo.lock b/Cargo.lock
index aa56c4116..9b17008e5 100644
--- a/Cargo.lock
+++ b/Cargo.lock
@@ -2595,6 +2595,7 @@ dependencies = [
  "shellexpand",
  "thiserror",
  "tracing",
+ "tracing-test",
 ]
 
 [[package]]
@@ -2979,6 +2980,29 @@ dependencies = [
  "tracing-log",
 ]
 
+[[package]]
+name = "tracing-test"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "3eb7bda2e93bbc9c5b247034acc6a4b3d04f033a3d4b8fc1cb87d4d1c7c7ebd7"
+dependencies = [
+ "lazy_static",
+ "tracing-core",
+ "tracing-subscriber",
+ "tracing-test-macro",
+]
+
+[[package]]
+name = "tracing-test-macro"
+version = "0.2.1"
+source = "registry+https://github.com/rust-lang/crates.io-index"
+checksum = "4801dca35e4e2cee957c469bd4a1c370fadb7894c0d50721a40eba3523e6e91c"
+dependencies = [
+ "lazy_static",
+ "quote",
+ "syn",
+]
+
 [[package]]
 name = "try-lock"
 version = "0.2.3"
diff --git a/crates/tor-config/Cargo.toml b/crates/tor-config/Cargo.toml
index 5311a6648..79808bc1c 100644
--- a/crates/tor-config/Cargo.toml
+++ b/crates/tor-config/Cargo.toml
@@ -25,3 +25,4 @@ directories = { version = "4.0.1", optional = true }
 
 [dev-dependencies]
 dirs = "4.0.0"
+tracing-test = "0.2.1"
diff --git a/crates/tor-config/src/lib.rs b/crates/tor-config/src/lib.rs
index 0a96431f9..b58b86797 100644
--- a/crates/tor-config/src/lib.rs
+++ b/crates/tor-config/src/lib.rs
@@ -69,9 +69,31 @@ impl Reconfigure {
                 })
             }
             Reconfigure::WarnOnFailures => {
-                tracing::warn!("Cannot change field {} on a running client", field.as_ref());
+                tracing::warn!("Cannot change {} on a running client.", field.as_ref());
                 Ok(())
             }
         }
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use tracing_test::traced_test;
+
+    #[test]
+    #[traced_test]
+    fn reconfigure_helpers() {
+        let how = Reconfigure::AllOrNothing;
+        let err = how.cannot_change("the_laws_of_physics").unwrap_err();
+        assert_eq!(
+            err.to_string(),
+            "Cannot change the_laws_of_physics on a running client.".to_owned()
+        );
+
+        let how = Reconfigure::WarnOnFailures;
+        let ok = how.cannot_change("stuff");
+        assert!(ok.is_ok());
+        assert!(logs_contain("Cannot change stuff on a running client."));
+    }
+}
diff --git a/crates/tor-config/src/mut_cfg.rs b/crates/tor-config/src/mut_cfg.rs
index 73a101d20..792b13fed 100644
--- a/crates/tor-config/src/mut_cfg.rs
+++ b/crates/tor-config/src/mut_cfg.rs
@@ -66,3 +66,48 @@ impl<T> From<T> for MutCfg<T> {
         MutCfg::new(config)
     }
 }
+
+#[cfg(test)]
+mod test {
+    use super::*;
+
+    #[test]
+    fn basic_constructors() {
+        let m = MutCfg::new(7_u32);
+        assert_eq!(*m.get(), 7);
+        let m: MutCfg<u32> = MutCfg::default();
+        assert_eq!(*m.get(), 0);
+        let m: MutCfg<u32> = 100.into();
+        assert_eq!(*m.get(), 100);
+    }
+
+    #[test]
+    fn mutate_with_existing_ref() {
+        let m = MutCfg::new(100_u32);
+        let old_ref = m.get();
+        m.replace(101);
+        assert_eq!(*old_ref, 100);
+        assert_eq!(*m.get(), 101);
+    }
+
+    #[test]
+    fn check_and_replace() {
+        let m = MutCfg::new(100_u32);
+        let different_100 = Arc::new(100_u32);
+        // won't replace, since it is a different arc.
+        assert!(!m.check_and_replace(&different_100, 200));
+        let old_100 = m.get();
+        assert_eq!(*old_100, 100);
+        assert!(m.check_and_replace(&old_100, 200));
+        assert_eq!(*m.get(), 200);
+    }
+
+    #[test]
+    fn map_and_replace() {
+        let m = MutCfg::new(100_u32);
+        let m_old = m.get();
+        m.map_and_replace(|old_val| **old_val * 20);
+        assert_eq!(*m.get(), 2000);
+        assert_eq!(*m_old, 100);
+    }
+}
diff --git a/crates/tor-dirmgr/src/lib.rs b/crates/tor-dirmgr/src/lib.rs
index 05e90d03f..89c51df41 100644
--- a/crates/tor-dirmgr/src/lib.rs
+++ b/crates/tor-dirmgr/src/lib.rs
@@ -443,9 +443,8 @@ impl<R: Runtime> DirMgr<R> {
             // was no current netdir.)
             self.netdir_consensus_changed.store(true, Ordering::SeqCst);
 
-            // TODO(nickm): need to make sure that notify gets called.  But
-            // first I should probably refactor notify() to be more like the
-            // backend for tor-events.
+            // TODO(nickm): need to make sure that notify gets called.  But first I should probably
+            // refactor notify() to be more like the backend for tor-events.
         }
 
         Ok(())