fix(ListWrapper): follow JS semantics

modules/angular2/test/facade/collection_spec.js

@@ -5,12 +5,68 @@ import {List, ListWrapper} from 'angular2/src/facade/collection';
 
 export function main() {
   describe('ListWrapper', () => {
+    var l: List;
+
     describe('splice', () => {
-      it('should remove sublist of given length and return it',  () => {
+      it('should remove sublist of given length and return it', () => {
         var list = [1, 2, 3, 4, 5, 6];
         expect(ListWrapper.splice(list, 1, 3)).toEqual([2, 3, 4]);
         expect(list).toEqual([1, 5, 6]);
       });
+
+      it('should support negative start', () => {
+        var list = [1, 2, 3, 4, 5, 6];
+        expect(ListWrapper.splice(list, -5, 3)).toEqual([2, 3, 4]);
+        expect(list).toEqual([1, 5, 6]);
+      });
+    });
+
+    describe('fill', () => {
+      beforeEach(() => {
+        l = [1, 2, 3, 4];
+      });
+
+      it('should fill the whole list if neither start nor end are specified', () => {
+        ListWrapper.fill(l, 9);
+        expect(l).toEqual([9, 9, 9, 9]);
+      });
+
+      it('should fill up to the end if end is not specified', () => {
+        ListWrapper.fill(l, 9, 1);
+        expect(l).toEqual([1, 9, 9, 9]);
+      });
+
+      it('should support negative start', () => {
+        ListWrapper.fill(l, 9, -1);
+        expect(l).toEqual([1, 2, 3, 9]);
+      });
+
+      it('should support negative end', () => {
+        ListWrapper.fill(l, 9, -2, -1);
+        expect(l).toEqual([1, 2, 9, 4]);
+      });
+    });
+
+    describe('slice', () => {
+      beforeEach(() => {
+        l = [1, 2, 3, 4];
+      });
+
+      it('should return the whole list if neither start nor end are specified', () => {
+        expect(ListWrapper.slice(l)).toEqual([1, 2, 3, 4]);
+      });
+
+      it('should return up to the end if end is not specified', () => {
+        expect(ListWrapper.slice(l, 1)).toEqual([2, 3, 4]);
+      });
+
+      it('should support negative start', () => {
+        expect(ListWrapper.slice(l, -1)).toEqual([4]);
+      });
+
+      it('should support negative end', () => {
+        expect(ListWrapper.slice(l, -3, -1)).toEqual([2, 3]);
+      });
     });
  });
 }