add unit test for links

tx-pool/src/component/links.rs

@@ -72,13 +72,17 @@ impl TxLinksMap {
             relation_ids.insert(id);
         }
         // for direct parents, we don't store children in links map
-        // so filter those not in links map now, they maybe removed from tx-pool now
+        // so filter those not in links map, they maybe removed from tx-pool now
         if relation == Relation::DirectParents {
             relation_ids.retain(|id| self.inner.contains_key(id));
         }
         relation_ids
     }
 
+    pub fn add_link(&mut self, short_id: ProposalShortId, links: TxLinks) {
+        self.inner.insert(short_id, links);
+    }
+
     pub fn calc_ancestors(&self, short_id: &ProposalShortId) -> HashSet<ProposalShortId> {
         self.calc_relative_ids(short_id, Relation::Parents)
     }

tx-pool/src/component/pool_map.rs

@@ -511,12 +511,14 @@ impl PoolMap {
             self.links.add_child(parent, short_id.clone());
         }
 
-        let links = TxLinks {
-            parents,
-            direct_parents,
-            children: Default::default(),
-        };
-        self.links.inner.insert(short_id, links);
+        self.links.add_link(
+            short_id,
+            TxLinks {
+                parents,
+                direct_parents,
+                children: Default::default(),
+            },
+        );
 
         Ok(true)
     }

tx-pool/src/component/tests/mod.rs

@@ -1,5 +1,6 @@
 mod chunk;
 mod entry;
+mod links;
 mod orphan;
 mod pending;
 mod proposed;