Started work on upgrading to 1.16.1. Not in a compilable state yet

remappedSrc/dan200/computercraft/shared/wired/InvariantChecker.java

@@ -0,0 +1,54 @@
+/*
+ * This file is part of ComputerCraft - http://www.computercraft.info
+ * Copyright Daniel Ratcliffe, 2011-2019. Do not distribute without permission.
+ * Send enquiries to dratcliffe@gmail.com
+ */
+
+package dan200.computercraft.shared.wired;
+
+import dan200.computercraft.ComputerCraft;
+
+/**
+ * Verifies certain elements of a network are "well formed".
+ *
+ * This adds substantial overhead to network modification, and so should only be enabled
+ * in a development environment.
+ */
+public final class InvariantChecker
+{
+    private static final boolean ENABLED = false;
+
+    private InvariantChecker() {}
+
+    public static void checkNode( WiredNode node )
+    {
+        if( !ENABLED ) return;
+
+        WiredNetwork network = node.network;
+        if( network == null )
+        {
+            ComputerCraft.log.error( "Node's network is null", new Exception() );
+            return;
+        }
+
+        if( network.nodes == null || !network.nodes.contains( node ) )
+        {
+            ComputerCraft.log.error( "Node's network does not contain node", new Exception() );
+        }
+
+        for( WiredNode neighbour : node.neighbours )
+        {
+            if( !neighbour.neighbours.contains( node ) )
+            {
+                ComputerCraft.log.error( "Neighbour is missing node", new Exception() );
+            }
+        }
+    }
+
+    public static void checkNetwork( WiredNetwork network )
+    {
+        if( !ENABLED ) return;
+
+        for( WiredNode node : network.nodes ) checkNode( node );
+    }
+}