Add simple test for cache

src/setup/cache.rs

@@ -74,3 +74,80 @@ where
       .map_err(std::convert::Into::into)
   }
 }
+
+#[cfg(test)]
+mod test {
+  use super::{Add, AddResult, Cache, Logger};
+  use crate::async_utils::{join, run};
+  use crate::resources::{FromArtifact, FromResource, Resource};
+  use async_trait::async_trait;
+  use std::fmt::Debug;
+  use std::rc::{Rc, Weak};
+
+  #[derive(Debug, PartialEq, Eq, Hash)]
+  struct TestResource<T>(&'static str, T);
+  impl<T> Resource for TestResource<T> {
+    type Artifact = ();
+  }
+
+  #[derive(Debug, Hash, PartialEq, Eq)]
+  enum Resources {
+    A(Rc<TestResource<&'static str>>),
+    B(Rc<TestResource<()>>),
+  }
+  impl FromResource<TestResource<&'static str>> for Resources {
+    fn from_resource(
+      inner: &Rc<TestResource<&'static str>>,
+    ) -> (Self, Weak<TestResource<&'static str>>) {
+      (Self::A(Rc::clone(&inner)), Rc::downgrade(&inner))
+    }
+  }
+  impl FromResource<TestResource<()>> for Resources {
+    fn from_resource(inner: &Rc<TestResource<()>>) -> (Self, Weak<TestResource<()>>) {
+      (Self::B(Rc::clone(&inner)), Rc::downgrade(&inner))
+    }
+  }
+
+  #[derive(Clone)]
+  struct Artifacts;
+  impl<V> FromArtifact<TestResource<V>> for Artifacts {
+    fn from_artifact(_from: ()) -> Self {
+      Self
+    }
+    #[allow(clippy::unused_unit)]
+    fn into_artifact(self) -> () {
+      #[allow(clippy::unused_unit)]
+      ()
+    }
+  }
+
+  struct Inner;
+
+  #[async_trait(?Send)]
+  impl<T: Debug + 'static> Add<TestResource<T>> for Inner {
+    async fn add(
+      &self,
+      logger: &Rc<Logger>,
+      resource: Rc<TestResource<T>>,
+      force_run: bool,
+    ) -> AddResult<TestResource<T>> {
+      Ok(((), resource.0 != "reached"))
+    }
+  }
+
+  #[test]
+  fn test() {
+    let log = Rc::new(slog::Logger::root(slog::Discard, slog::o!()));
+
+    let cache: Cache<_, Resources, Artifacts> = Cache::new(Inner);
+    run(async {
+      let reached = cache.add(&log, Rc::new(TestResource("reached", ())), false);
+      let a = cache.add(&log, Rc::new(TestResource("a", ())), false);
+      let b = cache.add(&log, Rc::new(TestResource("b", ())), false);
+      let (reached, a, b) = join!(reached, a, b);
+      assert_eq!(((), false), reached.unwrap());
+      assert_eq!(((), true), a.unwrap());
+      assert_eq!(((), true), b.unwrap());
+    })
+  }
+}