starting unit test for visitor gateway

src/Visitor/VisitorGateway.php

@@ -41,6 +41,9 @@ class VisitorGateway extends NodeVisitorAbstract implements State\VisitorContext
      */
     public function __construct(array $visitor, ReflectionContext $ref, GraphContext $grf, Graph $g)
     {
+        if (!count($visitor)) {
+            throw new \InvalidArgumentException("The visitors list cannot be empty");
+        }
         $this->graphCtx = $grf;
         $this->graph = $g;
         $this->reflectionCtx = $ref;

tests/Visitor/VisitorGatewayTest.php

@@ -0,0 +1,71 @@
+<?php
+
+/*
+ * Mondrian
+ */
+
+namespace Trismegiste\Mondrian\Tests\Visitor;
+
+use Trismegiste\Mondrian\Visitor\VisitorGateway;
+
+/**
+ * VisitorGatewayTest tests the VisitorGateway
+ */
+class VisitorGatewayTest extends \PHPUnit_Framework_TestCase
+{
+
+    protected $sut;
+    protected $reflectionCtx;
+    protected $graphCtx;
+    protected $graph;
+
+    private function buildVisitor(array $visitor = [])
+    {
+        $this->sut = new VisitorGateway($visitor, $this->reflectionCtx, $this->graphCtx, $this->graph);
+    }
+
+    protected function setUp()
+    {
+        $this->reflectionCtx = $this->getMock('Trismegiste\Mondrian\Transform\ReflectionContext');
+        $this->graphCtx = $this->getMockBuilder('Trismegiste\Mondrian\Transform\GraphContext')
+                ->disableOriginalConstructor()
+                ->getMock();
+        $this->graph = $this->getMock('Trismegiste\Mondrian\Graph\Graph');
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testEmpty()
+    {
+        $this->buildVisitor();
+    }
+
+    /**
+     * @expectedException \InvalidArgumentException
+     */
+    public function testBadState()
+    {
+        $this->buildVisitor(['sfd']);
+    }
+
+    public function testStateKey()
+    {
+        $state0 = $this->getMock('Trismegiste\Mondrian\Visitor\State\State');
+        $state0->expects($this->exactly(2))
+                ->method('getName')
+                ->will($this->returnValue('key0'));
+        $state0->expects($this->once())
+                ->method('setContext');
+
+        $state1 = $this->getMock('Trismegiste\Mondrian\Visitor\State\State');
+        $state1->expects($this->once())
+                ->method('getName')
+                ->will($this->returnValue('key1'));
+        $state1->expects($this->once())
+                ->method('setContext');
+
+        $this->buildVisitor([$state0, $state1]);
+    }
+
+}