Do reset a HasMany's collection when the relation gets 'set' with som…

…ething that isn't a Collection. Regression from PaulUithol#90; fixes PaulUithol#100.

backbone-relational.js

@@ -755,10 +755,20 @@
 				this.related = attr;
 			}
 			// Otherwise, 'attr' should be an array of related object ids.
-			// Re-use the current 'this.related' if it is a Backbone.Collection.
+			// Re-use the current 'this.related' if it is a Backbone.Collection, and remove any current entries.
+			// Otherwise, create a new collection.
 			else {
-				var coll = this.related instanceof Backbone.Collection ? this.related : new this.collectionType();
-				this.setRelated( this.prepareCollection( coll ) );
+				var coll;
+
+				if ( this.related instanceof Backbone.Collection ) {
+					coll = this.related;
+					coll.reset( [], { silent: true } );
+				}
+				else {
+					coll = this.prepareCollection( new this.collectionType() );
+				}
+
+				this.setRelated( coll );
 				this.findRelated( options );
 			}
 

test/tests.js

@@ -38,10 +38,15 @@ $(document).ready(function() {
 
 		return url;
 	};
-
-
+
+
+	/**
+	 * 'Zoo'
+	 */
+
 	window.Zoo = Backbone.RelationalModel.extend({
-		relations: [{
+		relations: [
+			{
 				type: Backbone.HasMany,
 				key: 'animals',
 				relatedModel: 'Animal',
@@ -50,7 +55,13 @@ $(document).ready(function() {
 					key: 'livesIn',
 					includeInJSON: 'id'
 				}
-			}]
+			},
+			{ // A simple HasMany without recursive relation
+				type: Backbone.HasMany,
+				key: 'visitors',
+				relatedModel: 'Visitor'
+			}
+		]
 	});
 
 	window.Animal = Backbone.RelationalModel.extend({
@@ -68,6 +79,12 @@ $(document).ready(function() {
 		model: Animal
 	});
 
+	window.Visitor = Backbone.RelationalModel.extend();
+
+
+	/**
+	 * House/Person/Job/Company
+	 */
 
 	window.House = Backbone.RelationalModel.extend({
 		relations: [{
@@ -86,7 +103,8 @@ $(document).ready(function() {
 	});
 
 	window.Person = Backbone.RelationalModel.extend({
-		relations: [{
+		relations: [
+			{
 				// Create a cozy, recursive, one-to-one relationship
 				type: Backbone.HasOne,
 				key: 'likesALot',
@@ -151,6 +169,7 @@ $(document).ready(function() {
 	});
 
 
+
 	window.Node = Backbone.RelationalModel.extend({
 		relations: [{
 				type: Backbone.HasOne,
@@ -1114,7 +1133,7 @@ $(document).ready(function() {
 				});
 
 			// Add job1 and job2 to the 'Person' side of the relation
-			var jobs = person1.get('jobs');
+			var jobs = person1.get( 'jobs' );
 
 			jobs.add( job1 );
 			ok( jobs.length === 1, "jobs.length is 1" );
@@ -1169,6 +1188,23 @@ $(document).ready(function() {
 			ok( ourHouse.get( 'occupants' ).id === undefined );
 		});
 
+
+		test( "Setting a new collection or array of ids updates the relation", function() {
+			var zoo = new Zoo();
+
+			var visitors =  [
+				{ name: 'Paul' }
+			];
+
+			zoo.set( 'visitors', visitors );
+
+			equal( zoo.get( 'visitors' ).length, 1 );
+
+			zoo.set( 'visitors', [] );
+
+			equal( zoo.get( 'visitors' ).length, 0 );
+		});
+
 		test( "Setting a custom collection in 'collectionType' uses that collection for instantiation", function() {
 			var zoo = new Zoo();
 
@@ -1188,7 +1224,7 @@ $(document).ready(function() {
 			ok( zoo.get( 'animals' ) instanceof AnimalCollection );
 		});
 
-		test( "Settings a new collection maintains that collection's current 'models'", function() {
+		test( "Setting a new collection maintains that collection's current 'models'", function() {
 			var zoo = new Zoo();
 
 			var animals = new AnimalCollection([
@@ -1211,7 +1247,7 @@ $(document).ready(function() {
 			equal( zoo.get( 'animals' ).length, 3 );
 		});
 
-		test( "Models found in 'findRelated' are all added in one go (and 'sort' will only be called once)", function() {
+		test( "Models found in 'findRelated' are all added in one go (so 'sort' will only be called once)", function() {
 			var count = 0,
 				sort = Backbone.Collection.prototype.sort;