Cleanup

node_modules/validator/es/lib/isISIN.js

@@ -1,5 +1,11 @@
 import assertString from './util/assertString';
-var isin = /^[A-Z]{2}[0-9A-Z]{9}[0-9]$/;
+var isin = /^[A-Z]{2}[0-9A-Z]{9}[0-9]$/; // this link details how the check digit is calculated:
+// https://www.isin.org/isin-format/. it is a little bit
+// odd in that it works with digits, not numbers. in order
+// to make only one pass through the ISIN characters, the
+// each alpha character is handled as 2 characters within
+// the loop.
+
 export default function isISIN(str) {
   assertString(str);
 
@@ -7,32 +13,48 @@ export default function isISIN(str) {
     return false;
   }
 
-  var checksumStr = str.replace(/[A-Z]/g, function (character) {
-    return parseInt(character, 36);
-  });
-  var sum = 0;
-  var digit;
-  var tmpNum;
-  var shouldDouble = true;
+  var _double = true;
+  var sum = 0; // convert values
 
-  for (var i = checksumStr.length - 2; i >= 0; i--) {
-    digit = checksumStr.substring(i, i + 1);
-    tmpNum = parseInt(digit, 10);
+  for (var i = str.length - 2; i >= 0; i--) {
+    if (str[i] >= 'A' && str[i] <= 'Z') {
+      var value = str[i].charCodeAt(0) - 55;
+      var lo = value % 10;
+      var hi = Math.trunc(value / 10); // letters have two digits, so handle the low order
+      // and high order digits separately.
 
-    if (shouldDouble) {
-      tmpNum *= 2;
+      for (var _i = 0, _arr = [lo, hi]; _i < _arr.length; _i++) {
+        var digit = _arr[_i];
 
-      if (tmpNum >= 10) {
-        sum += tmpNum + 1;
-      } else {
-        sum += tmpNum;
+        if (_double) {
+          if (digit >= 5) {
+            sum += 1 + (digit - 5) * 2;
+          } else {
+            sum += digit * 2;
+          }
+        } else {
+          sum += digit;
+        }
+
+        _double = !_double;
       }
     } else {
-      sum += tmpNum;
-    }
+      var _digit = str[i].charCodeAt(0) - '0'.charCodeAt(0);
 
-    shouldDouble = !shouldDouble;
+      if (_double) {
+        if (_digit >= 5) {
+          sum += 1 + (_digit - 5) * 2;
+        } else {
+          sum += _digit * 2;
+        }
+      } else {
+        sum += _digit;
+      }
+
+      _double = !_double;
+    }
   }
 
-  return parseInt(str.substr(str.length - 1), 10) === (10000 - sum) % 10;
+  var check = Math.trunc((sum + 9) / 10) * 10 - sum;
+  return +str[str.length - 1] === check;
 }