From 7a1800fd6866f7aac7ac27c9785f96bf1740a490 Mon Sep 17 00:00:00 2001
From: John Firebaugh <john.firebaugh@gmail.com>
Date: Wed, 27 Feb 2013 16:32:52 -0800
Subject: [PATCH] Delete orphaned relation members

---
 js/id/actions/delete_relation.js     | 15 +++++++
 test/spec/actions/delete_relation.js | 59 ++++++++++++++++++++++++++++
 2 files changed, 74 insertions(+)

diff --git a/js/id/actions/delete_relation.js b/js/id/actions/delete_relation.js
index 48c62f1e1..783f1533c 100644
--- a/js/id/actions/delete_relation.js
+++ b/js/id/actions/delete_relation.js
@@ -1,5 +1,11 @@
 // https://github.com/openstreetmap/potlatch2/blob/master/net/systemeD/halcyon/connection/actions/DeleteRelationAction.as
 iD.actions.DeleteRelation = function(relationId) {
+    function deleteEntity(entity, graph) {
+        return !graph.parentWays(entity).length &&
+            !graph.parentRelations(entity).length &&
+            !entity.hasInterestingTags();
+    }
+
     return function(graph) {
         var relation = graph.entity(relationId);
 
@@ -8,6 +14,15 @@ iD.actions.DeleteRelation = function(relationId) {
                 graph = graph.replace(parent.removeMember(relationId));
             });
 
+        _.uniq(_.pluck(relation.members, 'id')).forEach(function(memberId) {
+            graph = graph.replace(relation.removeMember(memberId));
+
+            var entity = graph.entity(memberId);
+            if (deleteEntity(entity, graph)) {
+                graph = iD.actions.DeleteMultiple([memberId])(graph);
+            }
+        });
+
         return graph.remove(relation);
     };
 };
diff --git a/test/spec/actions/delete_relation.js b/test/spec/actions/delete_relation.js
index c96909f3f..28219601a 100644
--- a/test/spec/actions/delete_relation.js
+++ b/test/spec/actions/delete_relation.js
@@ -14,4 +14,63 @@ describe("iD.actions.DeleteRelation", function () {
             graph  = action(iD.Graph([a, b, parent]));
         expect(graph.entity(parent.id).members).to.eql([{ id: b.id }]);
     });
+
+    it("deletes member nodes not referenced by another parent", function() {
+        var node     = iD.Node(),
+            relation = iD.Relation({members: [{id: node.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([node, relation]));
+        expect(graph.entity(node.id)).to.be.undefined;
+    });
+
+    it("does not delete member nodes referenced by another parent", function() {
+        var node     = iD.Node(),
+            way      = iD.Way({nodes: [node.id]}),
+            relation = iD.Relation({members: [{id: node.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([node, way, relation]));
+        expect(graph.entity(node.id)).not.to.be.undefined;
+    });
+
+    it("does not delete member nodes with interesting tags", function() {
+        var node     = iD.Node({tags: {highway: 'traffic_signals'}}),
+            relation = iD.Relation({members: [{id: node.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([node, relation]));
+        expect(graph.entity(node.id)).not.to.be.undefined;
+    });
+
+    it("deletes member ways not referenced by another parent", function() {
+        var way      = iD.Way(),
+            relation = iD.Relation({members: [{id: way.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([way, relation]));
+        expect(graph.entity(way.id)).to.be.undefined;
+    });
+
+    it("does not delete member ways referenced by another parent", function() {
+        var way       = iD.Way(),
+            relation1 = iD.Relation({members: [{id: way.id}]}),
+            relation2 = iD.Relation({members: [{id: way.id}]}),
+            action    = iD.actions.DeleteRelation(relation1.id),
+            graph     = action(iD.Graph([way, relation1, relation2]));
+        expect(graph.entity(way.id)).not.to.be.undefined;
+    });
+
+    it("does not delete member ways with interesting tags", function() {
+        var way      = iD.Node({tags: {highway: 'residential'}}),
+            relation = iD.Relation({members: [{id: way.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([way, relation]));
+        expect(graph.entity(way.id)).not.to.be.undefined;
+    });
+
+    it("deletes nodes of deleted member ways", function() {
+        var node     = iD.Node(),
+            way      = iD.Way({nodes: [node.id]}),
+            relation = iD.Relation({members: [{id: way.id}]}),
+            action   = iD.actions.DeleteRelation(relation.id),
+            graph    = action(iD.Graph([node, way, relation]));
+        expect(graph.entity(node.id)).to.be.undefined;
+    });
 });