diff: Sort exported port changes first

Author: jonnor

examples/real-life.yml

@@ -38,7 +38,7 @@
     ledchain SHOWN -> IN dummy(Forward)
     ledchain READY -> IN dummyB(Forward)
   diff: |
+    - OUTPORT=ledchain.PIXELSET:PIXELSET
     - "true" -> HWSPI ledchain
     + "2" -> PINDATA ledchain
     + "3" -> PINCLK ledchain
-    - OUTPORT=ledchain.PIXELSET:PIXELSET

src/diff.coffee

@@ -230,15 +230,15 @@ calculateDiff = (from, to) ->
   # this is just the basics/dry-fact view. Any heuristics etc is applied afterwards
   changes = []
 
+  # exported port changes
+  changes = changes.concat portChanges(from.inports, to.inports, 'inport')
+  changes = changes.concat portChanges(from.outports, to.outports, 'outport')
+
   # nodes added/removed
   changes = changes.concat processChanges(from.processes, to.processes)
 
   # edges added/removed
   changes = changes.concat connectionChanges(from.connections, to.connections)
-  
-  # exported port changes
-  changes = changes.concat portChanges(from.inports, to.inports, 'inport')
-  changes = changes.concat portChanges(from.outports, to.outports, 'outport')
 
   # FIXME: diff graph properties
   # TODO: support diffing of groups