From 66b451424408ce0ca1669c73e2e6895f04590c09 Mon Sep 17 00:00:00 2001
From: christophe-g <christophe.geiser@e-smile.org>
Date: Sat, 4 Feb 2017 18:12:50 +0100
Subject: [PATCH 1/2] sort function handled undefined, null or empty string
 values

---
 array-datasource.js | 8 +-------
 1 file changed, 1 insertion(+), 7 deletions(-)

diff --git a/array-datasource.js b/array-datasource.js
index a326521..6b17c78 100644
--- a/array-datasource.js
+++ b/array-datasource.js
@@ -19,13 +19,7 @@ function ArrayDataSource(arr) {
   }
 
   function _compare(a, b) {
-    if (a < b) {
-      return -1;
-    }
-    if (a > b) {
-      return 1;
-    }
-    return 0;
+    return (a===undefined)-(b===undefined) ||  (a==='')-(b==='') || (a===null)-(b===null) || +(a>b)||-(a<b);
   }
 
   function _sort(items, sortOrder) {

From 7316726f10cf85e620d850fa7ce33feb94b57065 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Sauli=20T=C3=A4hk=C3=A4p=C3=A4=C3=A4?= <sauli@vaadin.com>
Date: Fri, 21 Apr 2017 21:00:52 +0300
Subject: [PATCH 2/2] Add tests for empty sorting

---
 test/sorting.html | 44 ++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 44 insertions(+)

diff --git a/test/sorting.html b/test/sorting.html
index 2ccc666..8bc2e78 100644
--- a/test/sorting.html
+++ b/test/sorting.html
@@ -129,6 +129,50 @@
           expect(columnSort.direction).to.eql('desc');
         });
       });
+
+      describe('sorting empty values', function() {
+        beforeEach(function() {
+        });
+
+        it('should sort null values', function(done) {
+          grid.items = [{value: 'foo'}, {value: null}, {value: 'bar'}];
+
+          grid.push('sortOrder', {path: 'value', direction: 'asc'});
+
+          grid.async(function() {
+            expect(grid.$.list.items[0]).to.eql({value: 'bar'});
+            expect(grid.$.list.items[1]).to.eql({value: 'foo'});
+            expect(grid.$.list.items[2]).to.eql({value: null});
+            done();
+          }, 100);
+        });
+
+        it('should sort undefined values', function(done) {
+          grid.items = [{value: 'foo'}, {value: undefined}, {value: 'bar'}];
+
+          grid.push('sortOrder', {path: 'value', direction: 'asc'});
+
+          grid.async(function() {
+            expect(grid.$.list.items[0]).to.eql({value: 'bar'});
+            expect(grid.$.list.items[1]).to.eql({value: 'foo'});
+            expect(grid.$.list.items[2]).to.eql({value: undefined});
+            done();
+          }, 100);
+        });
+
+        it('should sort empty string values', function(done) {
+          grid.items = [{value: 'foo'}, {value: ''}, {value: 'bar'}];
+
+          grid.push('sortOrder', {path: 'value', direction: 'asc'});
+
+          grid.async(function() {
+            expect(grid.$.list.items[0]).to.eql({value: 'bar'});
+            expect(grid.$.list.items[1]).to.eql({value: 'foo'});
+            expect(grid.$.list.items[2]).to.eql({value: ''});
+            done();
+          }, 100);
+        });
+      })
     });
   </script>