bug(#25): fix issue with filterBy

src/app/pipes/array/order-by.spec.ts

@@ -14,6 +14,17 @@ describe('OrderByPipe', () => {
     pipe = new OrderByPipe();
   });
 
+  it ('should return dates in order asc', () => {
+    const a = new Date();
+    const b = new Date();
+    expect(pipe.transform([a, b], '+')).toEqual([a, b]);
+  });
+
+  it ('should return numbers in order asc', () => {
+    const numbers = [0, -1, 345, 1234, 1337, -3];
+    expect(pipe.transform(numbers, '+')).toEqual([-3, -1, 0, 345, 1234, 1337]);
+  });
+
   it('should not do anything in-case of not an array', () => {
     expect(pipe.transform('foo')).toEqual('foo');
     expect(pipe.transform(null)).toEqual(null);

src/app/pipes/array/order-by.ts

@@ -31,23 +31,25 @@ export class OrderByPipe implements PipeTransform {
 
       if (config.length === 1) {
         switch (sign) {
-          case '+': return out.sort();
-          case '-': return out.sort().reverse();
+          case '+': return out.sort(OrderByPipe.simpleSort.bind(this));
+          case '-': return out.sort(OrderByPipe.simpleSort.bind(this)).reverse();
         }
       }
 
       return out.sort(OrderByPipe.orderCompare.bind(this, prop, asc));
     }
 
     // default sort by value
-    return out.sort((a, b) => {
-      return isString(a) && isString(b)
-        ? a.toLowerCase().localeCompare(b.toLowerCase())
-        : a - b;
-    });
+    return out.sort(OrderByPipe.simpleSort.bind(this));
   }
 
-  static orderCompare(prop: string, asc: boolean, a: any, b: any) {
+  private static simpleSort(a: any, b: any) {
+    return isString(a) && isString(b)
+      ? a.toLowerCase().localeCompare(b.toLowerCase())
+      : a - b;
+  }
+
+  private static orderCompare(prop: string, asc: boolean, a: any, b: any) {
     const first = extractDeepPropertyByMapKey(a, prop),
           second = extractDeepPropertyByMapKey(b, prop);
 
@@ -65,7 +67,7 @@ export class OrderByPipe implements PipeTransform {
       : second - first;
   }
 
-  static extractFromConfig(config: any) {
+  private static extractFromConfig(config: any) {
     const sign = config.substr(0, 1);
     const prop = config.replace(/^[-+]/, '');
     const asc = sign !== '-';