From 02cd1a0dea2f8394b23af80f5bfe39e477bd3783 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Stefan=20M=C3=BCller?= <stefan.mueller@aksdb.de>
Date: Thu, 23 Apr 2026 18:18:36 +0200
Subject: [PATCH] Fix several minor issues in AppendGraph::are_adjacent(), unit
 tests, and formatting

---
 src/models/append_graph.rs | 28 +++++++++++++---------------
 1 file changed, 13 insertions(+), 15 deletions(-)

diff --git a/src/models/append_graph.rs b/src/models/append_graph.rs
index 4a76fe6..2423463 100644
--- a/src/models/append_graph.rs
+++ b/src/models/append_graph.rs
@@ -21,6 +21,7 @@ struct IncidenceEntry {
     next: Option<Incidence>,
     neighbor: Vertex,
 }
+
 struct VertexNeighborIterator<'a> {
     graph: &'a AppendGraph,
     incidence: Option<Incidence>,
@@ -85,7 +86,7 @@ impl GraphTopology for AppendGraph {
     }
 
     fn are_adjacent(&self, v1: Self::Vertex, v2: Self::Vertex) -> bool {
-        self.neighbors(v1).find(|&x| x == v2).is_some()
+        self.neighbors(v1).any(|x| x == v2)
     }
 
     fn vertices(&self) -> impl Iterator<Item = Self::Vertex> {
@@ -183,9 +184,8 @@ mod tests {
     fn are_adjacent_vertex_self() {
         let mut graph = AppendGraph::new();
         let v = graph.add_vertex();
-        assert_eq!(
-            graph.are_adjacent(v, v),
-            false,
+        assert!(
+            !graph.are_adjacent(v, v),
             "should not be adjacent to itself"
         );
     }
@@ -290,11 +290,11 @@ mod tests {
         assert_eq!(
             graph.neighbors(vertices[4]).count(),
             4,
-            "unexpected vertex count"
+            "unexpected neighbor count"
         );
 
         // Expects each neighbor to appear exactly once. This will not work if there are multiple edges.
-        let neighbors: Vec<Vertex> = vec![vertices[1], vertices[2], vertices[7], vertices[8]];
+        let neighbors = vec![vertices[1], vertices[2], vertices[7], vertices[8]];
         for v in graph.neighbors(vertices[4]) {
             assert_eq!(
                 neighbors.iter().filter(|&x| *x == v).count(),
@@ -313,9 +313,8 @@ mod tests {
         assert_eq!(graph.vertex_count(), 1, "unexpected vertex count");
         assert_eq!(graph.edge_count(), 1, "unexpected edge count");
         assert_eq!(graph.degree(v), 2, "unexpected degree");
-        assert_eq!(
+        assert!(
             graph.are_adjacent(v, v),
-            true,
             "vertex with loop edge should be adjacent to itself"
         );
         let mut neighbors = graph.neighbors(v);
@@ -334,10 +333,10 @@ mod tests {
 
     #[test]
     fn multiple_edges() {
-        let mult = 3;
+        let k = 3;
         let mut graph = AppendGraph::new();
         let vertices = [graph.add_vertex(), graph.add_vertex()];
-        for _ in 0..mult {
+        for _ in 0..k {
             graph.add_edge(vertices[0], vertices[1]);
         }
         assert_eq!(
@@ -345,18 +344,17 @@ mod tests {
             vertices.len(),
             "unexpected vertex count"
         );
-        assert_eq!(graph.edge_count(), mult, "unexpected edge count");
+        assert_eq!(graph.edge_count(), k, "unexpected edge count");
         for v in vertices {
-            assert_eq!(graph.degree(v), mult, "unexpected degree of {v:?}");
+            assert_eq!(graph.degree(v), k, "unexpected degree of {v:?}");
         }
-        assert_eq!(
+        assert!(
             graph.are_adjacent(vertices[0], vertices[1]),
-            true,
             "should be adjacent"
         );
         for i in 0..2 {
             let mut neighbors = graph.neighbors(vertices[i]);
-            for j in 0..mult {
+            for j in 0..k {
                 assert_eq!(
                     neighbors.next(),
                     Some(vertices[1 - i]),