fix(sortPipe): sort order not guaranteed when all items are equal

Author: dlabrecq

src/app/list/basic-list/list.component.html

@@ -34,7 +34,7 @@
   <!-- items -->
   <div class="list-pf-item {{item?.itemStyleClass}}"
        [ngClass]="{'active': item.selected || item.isItemExpanded}"
-       *ngFor="let item of (config.usePinItems ? (items | sortArray: 'showPin': true) : items); let i = index">
+       *ngFor="let item of (config.usePinItems ? (items | sortArray: 'showPin') : items); let i = index">
     <div class="list-pf-container">
       <!-- pin -->
       <div class="pfng-list-pin-container" *ngIf="config.usePinItems">

src/app/pipe/sort-array/examples/sort-array-example.component.html

@@ -53,7 +53,7 @@ <h5>Sort Array Descending by "name"</h5>
     <div class="col-sm-12">
       <h5>Sort Array Ascending by "name", Then Sort Descending by "pin"</h5>
       <div class="col-md-12"
-           *ngFor="let item of (items3 | sortArray: 'name' | sortArray: 'pin': true)">
+           *ngFor="let item of (items3 | sortArray: 'name' | sortArray: 'pin')">
         <div class="row">
           <div class="col-md-3">
             <span>{{item.name}}</span><strong *ngIf="item.pin"> (pinned)</strong>

src/app/pipe/sort-array/sort-array.pipe.spec.ts

@@ -63,7 +63,7 @@ describe('Sort array pipe', () => {
 
   it('should sort array by "name", then sort array by "pin"', () => {
     let sortedItems = pipe.transform(items, 'name');
-    sortedItems = pipe.transform(sortedItems, 'pin', true);
+    sortedItems = pipe.transform(sortedItems, 'pin');
     expect(sortedItems[0].name).toBe('Holly Nichols');
   });
 });

src/app/pipe/sort-array/sort-array.pipe.ts

@@ -1,5 +1,6 @@
 import { Pipe, PipeTransform } from '@angular/core';
-import { isBoolean, isString } from 'util';
+
+import { orderBy } from 'lodash';
 
 /**
  * Sort array pipe
@@ -21,25 +22,10 @@ export class SortArrayPipe implements PipeTransform {
    */
   transform(arr: Array<any>, prop: any, descending: boolean = false): any {
     if (arr === undefined) {
-      return;
+      return arr;
     }
-    const m = descending ? -1 : 1;
-    return arr.sort((a: any, b: any): number => {
-      let x = a[prop];
-      let y = b[prop];
-
-      // Resolve undefined values for more predicable behavior
-      if (x === undefined && isBoolean(y)) {
-        x = false;
-      } else if (x === undefined && isString(y)) {
-        x = '';
-      }
-      if (y === undefined && isBoolean(x)) {
-        y = false;
-      } else if (y === undefined && isString(x)) {
-        y = '';
-      }
-      return (x === y) ? 0 : (x < y) ? -1 * m : 1 * m;
-    });
+    const sortOrder = descending ? 'desc' : 'asc';
+    const sortedArray = orderBy(arr, [prop], [sortOrder]);
+    return sortedArray;
   }
 }