update

1 files changed, 51 insertions, 2 deletions

diff --git a/node_modules/source-map/lib/base64.js b/node_modules/source-map/lib/base64.js
index b9ca3199..8aa86b30 100644
--- a/node_modules/source-map/lib/base64.js
+++ b/node_modules/source-map/lib/base64.js
@@ -5,14 +5,63 @@
  * http://opensource.org/licenses/BSD-3-Clause
  */
 
-const intToCharMap = "ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/".split("");
+var intToCharMap = 'ABCDEFGHIJKLMNOPQRSTUVWXYZabcdefghijklmnopqrstuvwxyz0123456789+/'.split('');
 
 /**
  * Encode an integer in the range of 0 to 63 to a single base 64 digit.
  */
-exports.encode = function(number) {
+exports.encode = function (number) {
   if (0 <= number && number < intToCharMap.length) {
     return intToCharMap[number];
   }
   throw new TypeError("Must be between 0 and 63: " + number);
 };
+
+/**
+ * Decode a single base 64 character code digit to an integer. Returns -1 on
+ * failure.
+ */
+exports.decode = function (charCode) {
+  var bigA = 65;     // 'A'
+  var bigZ = 90;     // 'Z'
+
+  var littleA = 97;  // 'a'
+  var littleZ = 122; // 'z'
+
+  var zero = 48;     // '0'
+  var nine = 57;     // '9'
+
+  var plus = 43;     // '+'
+  var slash = 47;    // '/'
+
+  var littleOffset = 26;
+  var numberOffset = 52;
+
+  // 0 - 25: ABCDEFGHIJKLMNOPQRSTUVWXYZ
+  if (bigA <= charCode && charCode <= bigZ) {
+    return (charCode - bigA);
+  }
+
+  // 26 - 51: abcdefghijklmnopqrstuvwxyz
+  if (littleA <= charCode && charCode <= littleZ) {
+    return (charCode - littleA + littleOffset);
+  }
+
+  // 52 - 61: 0123456789
+  if (zero <= charCode && charCode <= nine) {
+    return (charCode - zero + numberOffset);
+  }
+
+  // 62: +
+  if (charCode == plus) {
+    return 62;
+  }
+
+  // 63: /
+  if (charCode == slash) {
+    return 63;
+  }
+
+  // Invalid base64 digit.
+  return -1;
+};