Follow up of pull request #626 (#627)

* Fix ReDoS in dice_coefficient

Fix ReDos in `dice_coefficient.js`

This related issue addresses #613

* Repaired a test for Dice coefficient

Co-authored-by: Yeting Li <[email protected]>

Author: Hugo-ter-Doest

lib/natural/distance/dice_coefficient.js

@@ -51,7 +51,7 @@ function intersect (set1, set2) {
 function sanitize (str) {
   // Turn characters to lower string, remove space at the beginning and end,
   // replace multiple spaces in the middle by single spaces
-  return str.toLowerCase().replace(/^\s+|\s+$/g, '').replace(/s+/g, ' ')
+  return str.toLowerCase().replace(/\s+/g, ' ').replace(/^\s+|\s+$/g, '')
 }
 
 function diceCoefficient (str1, str2) {

spec/dice_coefficient_spec.js

@@ -32,6 +32,6 @@ describe('dice', function () {
   it('should compare complete texts', function () {
     const text1 = require('./test_data/Wikipedia_EN_FrenchRevolution.json').text
     const text2 = require('./test_data/Wikipedia_EN_InfluenceOfTheFrenchRevolution.json').text
-    expect(dice(text1, text2)).toBe(0.7897503285151117)
+    expect(dice(text1, text2)).toBe(0.7939374395356337)
   })
 })