feat(currencyFilter): trim whitespace around an empty currency symbol

In most locales, this won't make a difference (since they do not have
whitespace around their currency symbols). In locales where there is a
whitespace separating the currency symbol from the number, it makes
sense to also remove such whitespace if the user specified an empty
currency symbol (indicating they just want the number).

Fixes angular#15018
Closes angular#15085

Closes angular#15105

Author: gkalpak

src/ng/filter/filters.js

@@ -68,11 +68,14 @@ function currencyFilter($locale) {
       fractionSize = formats.PATTERNS[1].maxFrac;
     }
 
+    // If the currency symbol is empty, trim whitespace around the symbol
+    var currencySymbolRe = !currencySymbol ? /\s*\u00A4\s*/g : /\u00A4/g;
+
     // if null or undefined pass it through
     return (amount == null)
         ? amount
         : formatNumber(amount, formats.PATTERNS[1], formats.GROUP_SEP, formats.DECIMAL_SEP, fractionSize).
-            replace(/\u00A4/g, currencySymbol);
+            replace(currencySymbolRe, currencySymbol);
   };
 }
 

test/ng/filter/filtersSpec.js

@@ -186,6 +186,19 @@ describe('filters', function() {
 
       expect(currency(1.07)).toBe('$1.1');
     }));
+
+    it('should trim whitespace around the currency symbol if it is empty',
+      inject(function($locale) {
+        var pattern = $locale.NUMBER_FORMATS.PATTERNS[1];
+        pattern.posPre = pattern.posSuf = '     \u00A4     ';
+        pattern.negPre = pattern.negSuf = '  -  \u00A4  -  ';
+
+        expect(currency(+1.07, '$')).toBe('     $     1.07     $     ');
+        expect(currency(-1.07, '$')).toBe('  -  $  -  1.07  -  $  -  ');
+        expect(currency(+1.07, '')).toBe('1.07');
+        expect(currency(-1.07, '')).toBe('  --  1.07  --  ');
+      })
+    );
   });
 
   describe('number', function() {