feat(currencyFilter): allow fractionSize to be specified

It should pass through the currency number pattern from the current locale

Closes angular#5674

Author: park9140

src/ng/filter/filters.js

@@ -11,6 +11,9 @@
  *
  * @param {number} amount Input to filter.
  * @param {string=} symbol Currency symbol or identifier to be displayed.
+ * @param {(number|string)=} fractionSize Number of decimal places to round the number to.
+ * If this is not provided then the fraction size is computed from the current locale's number
+ * formatting pattern. In the case of the default locale, it will be 3.
  * @returns {string} Formatted number.
  *
  *
@@ -51,9 +54,10 @@
 currencyFilter.$inject = ['$locale'];
 function currencyFilter($locale) {
   var formats = $locale.NUMBER_FORMATS;
-  return function(amount, currencySymbol){
+  return function(amount, currencySymbol, fractionSize){
     if (isUndefined(currencySymbol)) currencySymbol = formats.CURRENCY_SYM;
-    return formatNumber(amount, formats.PATTERNS[1], formats.GROUP_SEP, formats.DECIMAL_SEP, 2).
+    return formatNumber(amount, formats.PATTERNS[1], formats.GROUP_SEP, formats.DECIMAL_SEP,
+      fractionSize).
                 replace(/\u00A4/g, currencySymbol);
   };
 }
@@ -108,7 +112,6 @@ function currencyFilter($locale) {
    </example>
  */
 
-
 numberFilter.$inject = ['$locale'];
 function numberFilter($locale) {
   var formats = $locale.NUMBER_FORMATS;

test/ng/filter/filtersSpec.js

@@ -131,6 +131,18 @@ describe('filters', function() {
       expect(currency(0.008)).toBe('$0.01');
       expect(currency(0.003)).toBe('$0.00');
     });
+
+    it("should pass through the currency number format pattern from the current locale", inject(function($locale) {
+      $locale.NUMBER_FORMATS.PATTERNS[1].maxFrac = 1;
+      expect(currency(123.123, '$')).toBe('$123.1');
+      $locale.NUMBER_FORMATS.PATTERNS[1].maxFrac = 3;
+      expect(currency(123.123, '$')).toBe('$123.123');
+    }));
+
+    it('should handle overriding the default locale fractionSize', function() {
+      expect(currency(0.008, "$", 3)).toBe('$0.008');
+      expect(currency(0.008, "$", 0)).toBe('$0');
+    });
   });