Added showPlusSign option to currency filter

Resolve #76

Author: freearhey

README.md

@@ -248,6 +248,7 @@ export default {
   * `{String} [decimalSeparator] - default: '.'`
   * `{Boolean} [symbolOnLeft] - default: true`
   * `{Boolean} [spaceBetweenAmountAndSymbol] - default: false`
+  * `{Boolean} [showPlusSign] - default: false`
 
 + Example:
 
@@ -284,6 +285,12 @@ export default {
   ```js
   {{ amount | currency('$', 0, { spaceBetweenAmountAndSymbol: true }) }} // 12345 => $ 12,345
   ```
+
+  Show the plus sign if the value is greater than zero:
+
+  ```js
+  {{ amount | currency('$', 0, { showPlusSign: true }) }} // 12345 => +$12,345
+  ```
   Use multiple options:
 
   ```js
@@ -468,7 +475,8 @@ var Vue2FiltersConfig = {
     thousandsSeparator: ',',
     decimalSeparator: '.',
     symbolOnLeft: true,
-    spaceBetweenAmountAndSymbol: false
+    spaceBetweenAmountAndSymbol: false,
+    showPlusSign: false
   },
   pluralize: {
     includeNumber: false

src/other/currency.js

@@ -14,7 +14,7 @@ function currency (value, symbol, decimals, options) {
   symbol = util.exist(symbol) ? symbol : globalOptions.symbol
   decimals = util.exist(decimals) ? decimals : globalOptions.decimalDigits
   options = options || globalOptions
-  var thousandsSeparator, symbolOnLeft, spaceBetweenAmountAndSymbol
+  var thousandsSeparator, symbolOnLeft, spaceBetweenAmountAndSymbol, showPlusSign
   var digitsRE = /(\d{3})(?=\d)/g
   value = parseFloat(value)
   if (!isFinite(value) || (!value && value !== 0)) return ''
@@ -23,6 +23,7 @@ function currency (value, symbol, decimals, options) {
   thousandsSeparator = options.thousandsSeparator != null ? options.thousandsSeparator : ','
   symbolOnLeft = options.symbolOnLeft != null ? options.symbolOnLeft : true
   spaceBetweenAmountAndSymbol = options.spaceBetweenAmountAndSymbol != null ? options.spaceBetweenAmountAndSymbol : false
+  showPlusSign = options.showPlusSign != null ? options.showPlusSign : false
   var number = Math.abs(value)
   var stringified = toFixed(number, decimals)
   stringified = options.decimalSeparator
@@ -47,7 +48,8 @@ function currency (value, symbol, decimals, options) {
     : head +
       _int.slice(i).replace(digitsRE, '$1' + thousandsSeparator) + _float + symbol
   var sign = value < 0 ? '-' : ''
-  return sign + symbol
+  var plusSign = (value > 0 && showPlusSign) ? '+' : ''
+  return plusSign + sign + symbol
 }
 
 function toFixed(num, precision) {

test/filters.spec.js

@@ -145,6 +145,9 @@ describe('Filters', function() {
     expect(filter(1234, '$', 0, {spaceBetweenAmountAndSymbol: true})).toBe('$ 1,234')
     expect(filter(1234, '$', 0, {symbolOnLeft: false,spaceBetweenAmountAndSymbol: true})).toBe('1,234 $')
     expect(filter(-12345, 'VND', 0, {symbolOnLeft: true})).toBe('-VND12,345')
+    expect(filter(12345, 'VND', 0, {showPlusSign: true})).toBe('+VND12,345')
+    expect(filter(-12345, 'VND', 0, {showPlusSign: true})).toBe('-VND12,345')
+    expect(filter(0, 'VND', 0, {showPlusSign: true})).toBe('VND0')
     // round up
     expect(filter(4514.275)).toBe('$4,514.28')
     expect(filter(9446.975)).toBe('$9,446.98')
@@ -158,11 +161,12 @@ describe('Filters', function() {
         thousandsSeparator: ',',
         decimalSeparator: '|',
         symbolOnLeft: false,
-        spaceBetweenAmountAndSymbol: true
+        spaceBetweenAmountAndSymbol: true,
+        showPlusSign: true
       }
     })
 
-    expect(filter(1234)).toBe('1,234|000 @')
+    expect(filter(1234)).toBe('+1,234|000 @')
   })
 
   it('pluralize', function() {