deleteAll returns number of deleted records

The number is returned as `data.ctx` to `cb(null, data)`.

lib/connectors/memory.js

@@ -545,17 +545,20 @@ Memory.prototype.destroyAll = function destroyAll(model, where, callback) {
   }
   var cache = this.collection(model);
   var filter = null;
+  var count = 0;
   if (where) {
     filter = applyFilter({where: where});
     Object.keys(cache).forEach(function (id) {
       if (!filter || filter(this.fromDb(model, cache[id]))) {
+        count++;
         delete cache[id];
       }
     }.bind(this));
   } else {
+    count = Object.keys(cache).length;
     this.collection(model, {});
   }
-  this.saveToFile(null, callback);
+  this.saveToFile({ count: count }, callback);
 };
 
 Memory.prototype.count = function count(model, callback, where) {

test/basic-querying.test.js

@@ -602,25 +602,6 @@ describe('basic-querying', function () {
 
   });
 
-  describe('destroyAll with where option', function () {
-
-    before(seed);
-
-    it('should only delete instances that satisfy the where condition', function (done) {
-      User.destroyAll({name: 'John Lennon'}, function () {
-        User.find({where: {name: 'John Lennon'}}, function (err, data) {
-          should.not.exist(err);
-          data.length.should.equal(0);
-          User.find({where: {name: 'Paul McCartney'}}, function (err, data) {
-            should.not.exist(err);
-            data.length.should.equal(1);
-            done();
-          });
-        });
-      });
-    });
-
-  });
 
   describe('updateAll ', function () {
 

test/manipulation.test.js

@@ -735,6 +735,59 @@ describe('manipulation', function () {
     it('should destroy filtered set of records');
   });
 
+  describe('deleteAll/destroyAll', function () {
+    beforeEach(function clearOldData(done) {
+      Person.deleteAll(done);
+    });
+
+    beforeEach(function createTestData(done) {
+      Person.create([
+        { name: 'John' },
+        { name: 'Jane' }
+      ], done);
+    });
+
+    it('should only delete instances that satisfy the where condition', function (done) {
+      Person.deleteAll({name: 'John'}, function (err, data) {
+        if (err) return done(err);
+        data.count.should.equal(1);
+        Person.find({where: {name: 'John'}}, function (err, data) {
+          if (err) return done(err);
+          data.should.have.length(0);
+          Person.find({where: {name: 'Jane'}}, function (err, data) {
+            if (err) return done(err);
+            data.should.have.length(1);
+            done();
+          });
+        });
+      });
+    });
+
+    it('should report zero deleted instances', function (done) {
+      Person.deleteAll({name: 'does-not-match'}, function (err, data) {
+        if (err) return done(err);
+        data.count.should.equal(0);
+        Person.count(function(err, count) {
+          if (err) return done(err);
+          count.should.equal(2);
+          done();
+        });
+      });
+    });
+
+    it('should delete all instances when "where" is not provided', function(done) {
+      Person.deleteAll(function (err, data) {
+        if (err) return done(err);
+        data.count.should.equal(2);
+        Person.count(function(err, count) {
+          if (err) return done(err);
+          count.should.equal(0);
+          done();
+        });
+      });
+    });
+  });
+
   describe('initialize', function () {
     it('should initialize object properly', function () {
       var hw = 'Hello word',