From 2e62e78901b0814aca4260de120b2765d9123df6 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Christian=20L=C3=BCck?= <christian@clue.engineering>
Date: Sat, 28 Sep 2019 00:04:36 +0200
Subject: [PATCH] Fix returning directed loop edges & adjacent vertices from
 vertex twice

---
 src/Vertex.php       | 26 ++++++++++++++++++++++----
 tests/VertexTest.php | 26 ++++++++++++++++++++++++++
 2 files changed, 48 insertions(+), 4 deletions(-)

diff --git a/src/Vertex.php b/src/Vertex.php
index 13e5b9cf..4701c5ae 100644
--- a/src/Vertex.php
+++ b/src/Vertex.php
@@ -229,9 +229,18 @@ public function getEdges()
     public function getEdgesOut()
     {
         $that = $this;
+        $prev = null;
 
-        return $this->getEdges()->getEdgesMatch(function (Edge $edge) use ($that) {
-            return $edge->hasVertexStart($that);
+        return $this->getEdges()->getEdgesMatch(function (Edge $edge) use ($that, &$prev) {
+            $ret = $edge->hasVertexStart($that);
+
+            // skip duplicate directed loop edges
+            if ($edge === $prev && $edge instanceof EdgeDirected) {
+                $ret = false;
+            }
+            $prev = $edge;
+
+            return $ret;
         });
     }
 
@@ -243,9 +252,18 @@ public function getEdgesOut()
     public function getEdgesIn()
     {
         $that = $this;
+        $prev = null;
+
+        return $this->getEdges()->getEdgesMatch(function (Edge $edge) use ($that, &$prev) {
+            $ret = $edge->hasVertexTarget($that);
+
+            // skip duplicate directed loop edges
+            if ($edge === $prev && $edge instanceof EdgeDirected) {
+                $ret = false;
+            }
+            $prev = $edge;
 
-        return $this->getEdges()->getEdgesMatch(function (Edge $edge) use ($that) {
-            return $edge->hasVertexTarget($that);
+            return $ret;
         });
     }
 
diff --git a/tests/VertexTest.php b/tests/VertexTest.php
index 69103e39..3451aaa5 100644
--- a/tests/VertexTest.php
+++ b/tests/VertexTest.php
@@ -75,6 +75,32 @@ public function testEdges()
         $this->assertEquals(array($v3, $v4), $this->vertex->getVerticesEdgeFrom()->getVector());
     }
 
+    public function testUndirectedLoopEdgeReturnsEdgeTwiceInAndOut()
+    {
+        $edge = $this->vertex->createEdge($this->vertex);
+
+        $this->assertEquals(array($edge, $edge), $this->vertex->getEdges()->getVector());
+        $this->assertEquals(array($edge, $edge), $this->vertex->getEdgesIn()->getVector());
+        $this->assertEquals(array($edge, $edge), $this->vertex->getEdgesOut()->getVector());
+
+        $this->assertEquals(array($this->vertex, $this->vertex), $this->vertex->getVerticesEdge()->getVector());
+        $this->assertEquals(array($this->vertex, $this->vertex), $this->vertex->getVerticesEdgeTo()->getVector());
+        $this->assertEquals(array($this->vertex, $this->vertex), $this->vertex->getVerticesEdgeFrom()->getVector());
+    }
+
+    public function testDirectedLoopEdgeReturnsEdgeTwiceUndirectedAndOnceEachInAndOut()
+    {
+        $edge = $this->vertex->createEdgeTo($this->vertex);
+
+        $this->assertEquals(array($edge, $edge), $this->vertex->getEdges()->getVector());
+        $this->assertEquals(array($edge), $this->vertex->getEdgesIn()->getVector());
+        $this->assertEquals(array($edge), $this->vertex->getEdgesOut()->getVector());
+
+        $this->assertEquals(array($this->vertex, $this->vertex), $this->vertex->getVerticesEdge()->getVector());
+        $this->assertEquals(array($this->vertex), $this->vertex->getVerticesEdgeTo()->getVector());
+        $this->assertEquals(array($this->vertex), $this->vertex->getVerticesEdgeFrom()->getVector());
+    }
+
     public function testBalance()
     {
         $this->vertex->setBalance(10);