alternate implementation, support decimals, extra tests, benchmarking

.npmignore

@@ -1 +1,2 @@
 test
+benchmark/

README.md

@@ -17,16 +17,21 @@ var commaNumber = require('comma-number')
 commaNumber(1000) // "1,000"
 commaNumber(-1000) // "-1,000"
 commaNumber(-1000, '.') // "-1.000"
+
+commaNumber(1000.12) // "1,000.12"
+commaNumber(-1000.12) // "-1,000.12"
+commaNumber('-1000,12', '.', ',') // "-1.000,12"
 ```
 
 ## API
 
-### commaNumber(number, [separator=','])
+### commaNumber(number, [separator=','], [decimalChar='.'])
 
 **Parameters:**
 
 * number : {(Number|String)} Number to format
 * separator : {String} Value used to separate numbers
+* decimalChar : {String} Value used to separate the decimal value
 
 **Returns:**
 

benchmark/original.js

@@ -0,0 +1,45 @@
+/**
+ * Comma number formatter
+ * @param {Number} number Number to format
+ * @param {String} [separator=','] Value used to separate numbers
+ * @returns {String} Comma formatted number
+ */
+module.exports = function commaNumber (number, separator) {
+  separator = typeof separator === 'undefined' ? ',' : ('' + separator)
+
+  // Convert to number if it's a non-numeric value
+  if (typeof number !== 'number') {
+    number = Number(number)
+  }
+
+  // NaN => 0
+  if (isNaN(number)) {
+    number = 0
+  }
+
+  // Return Infinity immediately
+  if (!isFinite(number)) {
+    return '' + number
+  }
+
+  var stringNumber = ('' + Math.abs(number))
+    .split('')
+    .reverse()
+
+  var result = []
+  for (var i = 0; i < stringNumber.length; i++) {
+    if (i && i % 3 === 0) {
+      result.push(separator)
+    }
+    result.push(stringNumber[i])
+  }
+
+  // Handle negative numbers
+  if (number < 0) {
+    result.push('-')
+  }
+
+  return result
+    .reverse()
+    .join('')
+}

benchmark/run.js

@@ -0,0 +1,84 @@
+require('console.table')
+var comma = require('../')
+  , Benchmark = require('benchmark')
+
+Benchmark.options.initCount  = 10
+Benchmark.options.minSamples = 10
+
+// useful when altering things because it runs once per.
+// Benchmark.options.initCount = 1
+// Benchmark.options.minSamples = 1
+// Benchmark.options.minTime = -1
+// Benchmark.options.maxTime = -1
+
+inputs = [
+  '1',
+  '12',
+  '123',
+  '1234',
+  '12345',
+  '123456',
+  '1234567',
+  '12345678',
+  '123456789',
+  '1234567890',
+  '12345678901',
+  '123456789012',
+
+  1,
+  12,
+  123,
+  1234,
+  12345,
+  123456,
+  1234567,
+  12345678,
+  123456789,
+  1234567890,
+  12345678901,
+  123456789012
+]
+
+var methods = [
+  require('./original'),
+  comma
+]
+
+var suite = new Benchmark.Suite
+  , headers = [' ', 'original', 'alternate']
+  , results = []
+
+for (var i = 0; i < inputs.length; i++) {
+  var input = inputs[i]
+    , name = typeof input === 'string' ? '\'' + input + '\'' : input
+
+  results.push([name])
+
+  suite.add(name, methods[0].bind(null, input))
+  suite.add(name, methods[1].bind(null, input))
+}
+
+var columns = methods.length + 1
+  , row = 0
+
+suite.on('cycle', function(event) {
+  var it = event.target
+    , which = results[row].length === 1 ? ' original' : 'alternate'
+
+  console.log(which,'completed',it.name)
+
+  results[row].push(comma(it.hz.toFixed(2)) + ' (+-' + it.stats.rme.toFixed(2) + '%)')
+
+  if (results[row].length === columns) {
+    return row++
+  }
+})
+
+suite.on('complete', function() {
+  console.log()
+  console.table(headers, results)
+})
+
+suite.run({
+  async: false
+})

lib/index.js

@@ -2,44 +2,74 @@
  * Comma number formatter
  * @param {Number} number Number to format
  * @param {String} [separator=','] Value used to separate numbers
+ * @param {String} [decimalChar='.'] Decimal character
  * @returns {String} Comma formatted number
  */
-module.exports = function commaNumber (number, separator) {
-  separator = typeof separator === 'undefined' ? ',' : ('' + separator)
+module.exports = function commaNumber (number, separator, decimalChar) {
 
-  // Convert to number if it's a non-numeric value
+  // get the stringNumber based on type, or, return '0' for invalid types
+  var stringNumber
+  switch(typeof number) {
+    case 'string': stringNumber = number         ; break
+    case 'number': stringNumber = String(number) ; break
+    default      : return '0' // object, undefined, function, array, ...
+  }
+
+  // strip off decimal value to append to final result at the bottom
+  decimalChar = typeof decimalChar === 'undefined' ? '.' : String(decimalChar)
+  var decimal = stringNumber.lastIndexOf(decimalChar)
+  if (decimal > -1) {
+    number = stringNumber.slice(0, decimal)
+    decimal = stringNumber.slice(decimal)
+    stringNumber = number
+  } else {
+    decimal = null
+  }
+
+  // ensure we have an actual number
   if (typeof number !== 'number') {
     number = Number(number)
   }
 
+  // when it doesn't need a separator then return it (w/decimal, if exists)
+  if (-1000 < number && number < 1000) {
+    return decimal ? stringNumber + decimal : stringNumber
+  }
+
   // NaN => 0
   if (isNaN(number)) {
-    number = 0
+    return '0'
   }
 
   // Return Infinity immediately
-  if (!isFinite(number)) {
-    return '' + number
+  if (!isFinite(number) ) {
+    return stringNumber
   }
 
-  var stringNumber = ('' + Math.abs(number))
-    .split('')
-    .reverse()
+  // below here we split the number at spots to add a separator.
+  // then, combine it with the separator and add decimal value (if exists)
+
+  var start = stringNumber[0] === '-' ? 1 : 0  // start after minus sign
+    , count = stringNumber.length - start - 1  // count digits after first
+    , strings = []                             // hold string parts
+    , i = (count % 3) + 1 + start              // index for first separator
 
-  var result = []
-  for (var i = 0; i < stringNumber.length; i++) {
-    if (i && i % 3 === 0) {
-      result.push(separator)
-    }
-    result.push(stringNumber[i])
+  // grab string content before where the first separator belongs
+  strings.push(stringNumber.slice(0, i))
+
+  // split remaining string in groups of 3 where a separator belongs
+  for (; i < stringNumber.length; i += 3) {
+    strings.push(stringNumber.substr(i, 3))
   }
 
-  // Handle negative numbers
-  if (number < 0) {
-    result.push('-')
+  // finally, combine groups with the separator
+  separator = typeof separator === 'undefined' ? ',' : String(separator)
+  stringNumber = strings.join(separator)
+
+  // if there's a decimal value then append it
+  if (decimal) {
+    stringNumber += decimal
   }
 
-  return result
-    .reverse()
-    .join('')
+  return stringNumber
 }

package.json

@@ -27,6 +27,8 @@
   },
   "homepage": "https://github.com/cesarandreu/comma-number#readme",
   "devDependencies": {
+    "benchmark": "^2.1.2",
+    "console.table": "^0.7.0",
     "standard": "^4.5.4",
     "tape": "^4.0.0"
   }