trees over working links

1 files changed, 51 insertions, 0 deletions

diff --git a/src/swarm/topology/tests.rs b/src/swarm/topology/tests.rs
index 1b9c75d..ede3b6b 100644
--- a/src/swarm/topology/tests.rs
+++ b/src/swarm/topology/tests.rs
@@ -489,3 +489,54 @@ fn the_swarms_neighbours_count() {
     }
     assert!(affects_neighbours(&neighbours_path()));
 }
+
+/// The links members recorded: one either end recorded as unreached is out of the
+/// graph, both ways, even where the other end recorded it as reached; one recorded as
+/// reached is in, between members the graph has; the rest stays.
+#[test]
+fn recorded_links_change_the_graph() {
+    use crate::swarm::members::RecordedLinks;
+    let name = |n: &str| n.to_owned();
+    let set = |names: &[&str]| names.iter().map(|n| name(n)).collect::<BTreeSet<String>>();
+    let ring: BTreeMap<String, BTreeSet<String>> = [
+        ("a", set(&["b", "d"])),
+        ("b", set(&["a", "c"])),
+        ("c", set(&["b", "d"])),
+        ("d", set(&["c", "a"])),
+    ]
+    .into_iter()
+    .map(|(member, neighbours)| (name(member), neighbours))
+    .collect();
+    let recorded: BTreeMap<String, RecordedLinks> = [
+        (
+            name("a"),
+            RecordedLinks {
+                unreached: set(&["b"]),
+                reached: set(&["c", "stranger"]),
+            },
+        ),
+        (
+            name("b"),
+            RecordedLinks {
+                unreached: BTreeSet::new(),
+                reached: set(&["d"]),
+            },
+        ),
+        (
+            name("d"),
+            RecordedLinks {
+                unreached: set(&["b"]),
+                reached: BTreeSet::new(),
+            },
+        ),
+    ]
+    .into_iter()
+    .collect();
+    let changed = with_recorded(&ring, &recorded);
+    assert_eq!(changed[&name("a")], set(&["c", "d"]));
+    assert_eq!(changed[&name("b")], set(&["c"]));
+    assert_eq!(changed[&name("c")], set(&["a", "b", "d"]));
+    assert_eq!(changed[&name("d")], set(&["a", "c"]));
+    assert!(!changed.contains_key("stranger"));
+    assert_eq!(with_recorded(&ring, &BTreeMap::new()), ring);
+}