From 14c2fd1edda09b77e7d22f22f0984965bb1fa6fe Mon Sep 17 00:00:00 2001
From: James Shubin <james@shubin.ca>
Date: Wed, 31 May 2017 17:20:54 -0400
Subject: [PATCH] resources: Add proper edge compare method

Might as well do this cleanly in one place.
---
 lib/main.go            |  6 +++---
 resources/autogroup.go |  1 +
 resources/edge.go      | 15 +++++++++++++++
 3 files changed, 19 insertions(+), 3 deletions(-)

diff --git a/lib/main.go b/lib/main.go
index 2d42ef4c..771a7217 100644
--- a/lib/main.go
+++ b/lib/main.go
@@ -493,9 +493,9 @@ func (obj *Main) Run() error {
 				return nil
 			}
 			edgeCmpFn := func(e1, e2 pgraph.Edge) (bool, error) {
-				edge1 := e1.(*resources.Edge)                                        // panic if wrong
-				edge2 := e2.(*resources.Edge)                                        // panic if wrong
-				return edge1.Name == edge2.Name && edge1.Notify == edge2.Notify, nil // simple cmp
+				edge1 := e1.(*resources.Edge) // panic if wrong
+				edge2 := e2.(*resources.Edge) // panic if wrong
+				return edge1.Compare(edge2), nil
 			}
 			// on success, this updates the receiver graph...
 			if err := oldGraph.GraphSync(newGraph, vertexCmpFn, vertexAddFn, vertexRemoveFn, edgeCmpFn); err != nil {
diff --git a/resources/autogroup.go b/resources/autogroup.go
index a9abf62b..ec304a81 100644
--- a/resources/autogroup.go
+++ b/resources/autogroup.go
@@ -146,6 +146,7 @@ func (ag *baseGrouper) vertexMerge(v1, v2 pgraph.Vertex) (v pgraph.Vertex, err e
 }
 
 func (ag *baseGrouper) edgeMerge(e1, e2 pgraph.Edge) pgraph.Edge {
+	// FIXME: should we merge the edge.Notify or edge.refresh values?
 	return e1 // noop
 }
 
diff --git a/resources/edge.go b/resources/edge.go
index b7207b76..7ccdaecb 100644
--- a/resources/edge.go
+++ b/resources/edge.go
@@ -30,6 +30,21 @@ func (obj *Edge) String() string {
 	return obj.Name
 }
 
+// Compare returns true if two edges are equivalent. Otherwise it returns false.
+func (obj *Edge) Compare(edge *Edge) bool {
+	if obj.Name != edge.Name {
+		return false
+	}
+	if obj.Notify != edge.Notify {
+		return false
+	}
+	// FIXME: should we compare this as well?
+	//if obj.refresh != edge.refresh {
+	//	return false
+	//}
+	return true
+}
+
 // Refresh returns the pending refresh status of this edge.
 func (obj *Edge) Refresh() bool {
 	return obj.refresh