Add unit test for IONode minimum audio port count

Verifies that Audio Input/Output nodes receive a minimum of 2 ports
when added to a graph with zero audio ports configured.

Author: mfisher31

test/audioroutingtests.cpp

@@ -1032,4 +1032,33 @@ BOOST_AUTO_TEST_CASE (AudioFeedbackPrevention)
     BOOST_REQUIRE (! feedbackAllowed);
 }
 
+BOOST_AUTO_TEST_CASE (IONodeMinimumAudioPortCount)
+{
+    // Test that Audio I/O nodes get a minimum port count when added to a graph with zero audio ports
+    // This prevents the bug where Audio Input/Output nodes appear with zero ports
+    
+    PreparedGraph fix;
+    GraphNode& graph = fix.graph;
+
+    fix.graph.clear();
+    graph.setNumPorts (PortType::Audio, 0, true, false);
+    graph.setNumPorts (PortType::Audio, 0, false, false);
+
+    // Verify graph starts with zero audio ports configured
+    BOOST_REQUIRE_EQUAL (graph.getNumPorts (PortType::Audio, true), 0);
+    BOOST_REQUIRE_EQUAL (graph.getNumPorts (PortType::Audio, false), 0);
+    
+    // Add Audio Input node - should set graph audio inputs to minimum 2 (stereo)
+    auto* audioIn = new IONode (IONode::audioInputNode);
+    graph.addNode (audioIn);
+    BOOST_REQUIRE_EQUAL (graph.getNumPorts (PortType::Audio, true), 2);
+    BOOST_REQUIRE_EQUAL (audioIn->getNumPorts(), 2);
+    
+    // Add Audio Output node - should set graph audio outputs to minimum 2 (stereo)
+    auto* audioOut = new IONode (IONode::audioOutputNode);
+    graph.addNode (audioOut);
+    BOOST_REQUIRE_EQUAL (graph.getNumPorts (PortType::Audio, false), 2);
+    BOOST_REQUIRE_EQUAL (audioOut->getNumPorts(), 2);
+}
+
 BOOST_AUTO_TEST_SUITE_END()