fix(iroh): Implement Clone for StaticProvider discovery

This is not very useful without Clone, it already is Arc<RwLock<T>> on
the inside to this clearly was intended.  Write a test demonstrating
why this is needed.

Author: flub

iroh/src/discovery/static_provider.rs

@@ -12,7 +12,7 @@ use iroh_base::{NodeAddr, NodeId, RelayUrl};
 use super::{Discovery, DiscoveryItem};
 
 /// A static discovery implementation that allows providing info for nodes manually.
-#[derive(Debug, Default)]
+#[derive(Debug, Default, Clone)]
 #[repr(transparent)]
 pub struct StaticProvider {
     nodes: Arc<RwLock<BTreeMap<NodeId, NodeInfo>>>,
@@ -170,3 +170,34 @@ impl Discovery for StaticProvider {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use iroh_base::SecretKey;
+    use testresult::TestResult;
+
+    use super::*;
+    use crate::Endpoint;
+
+    #[tokio::test]
+    async fn test_basic() -> TestResult {
+        let discovery = StaticProvider::new();
+
+        let _ep = Endpoint::builder()
+            .add_discovery({
+                let discovery = discovery.clone();
+                move |_| Some(discovery)
+            })
+            .bind()
+            .await?;
+
+        let key = SecretKey::from_bytes(&[0u8; 32]);
+        discovery.add_node_addr(NodeAddr {
+            node_id: key.public(),
+            relay_url: Some("https://example.com".parse()?),
+            direct_addresses: Default::default(),
+        });
+
+        Ok(())
+    }
+}