update node modules

node_modules/abab/lib/atob.js

@@ -1,81 +1,78 @@
-'use strict';
+"use strict";
 
 /**
- * Implementation of atob() according to the HTML spec, except that instead of
- * throwing INVALID_CHARACTER_ERR we return null.
+ * Implementation of atob() according to the HTML and Infra specs, except that
+ * instead of throwing INVALID_CHARACTER_ERR we return null.
  */
-function atob(input) {
-  // WebIDL requires DOMStrings to just be converted using ECMAScript
-  // ToString, which in our case amounts to calling String().
-  input = String(input);
-  // "Remove all space characters from input."
-  input = input.replace(/[ \t\n\f\r]/g, '');
-  // "If the length of input divides by 4 leaving no remainder, then: if
-  // input ends with one or two U+003D EQUALS SIGN (=) characters, remove
-  // them from input."
-  if (input.length % 4 == 0 && /==?$/.test(input)) {
-    input = input.replace(/==?$/, '');
+function atob(data) {
+  // Web IDL requires DOMStrings to just be converted using ECMAScript
+  // ToString, which in our case amounts to using a template literal.
+  data = `${data}`;
+  // "Remove all ASCII whitespace from data."
+  data = data.replace(/[ \t\n\f\r]/g, "");
+  // "If data's length divides by 4 leaving no remainder, then: if data ends
+  // with one or two U+003D (=) code points, then remove them from data."
+  if (data.length % 4 === 0) {
+    data = data.replace(/==?$/, "");
   }
-  // "If the length of input divides by 4 leaving a remainder of 1, throw an
-  // INVALID_CHARACTER_ERR exception and abort these steps."
+  // "If data's length divides by 4 leaving a remainder of 1, then return
+  // failure."
   //
-  // "If input contains a character that is not in the following list of
-  // characters and character ranges, throw an INVALID_CHARACTER_ERR
-  // exception and abort these steps:
+  // "If data contains a code point that is not one of
   //
-  // U+002B PLUS SIGN (+)
-  // U+002F SOLIDUS (/)
-  // U+0030 DIGIT ZERO (0) to U+0039 DIGIT NINE (9)
-  // U+0041 LATIN CAPITAL LETTER A to U+005A LATIN CAPITAL LETTER Z
-  // U+0061 LATIN SMALL LETTER A to U+007A LATIN SMALL LETTER Z"
-  if (input.length % 4 == 1 || !/^[+/0-9A-Za-z]*$/.test(input)) {
+  // U+002B (+)
+  // U+002F (/)
+  // ASCII alphanumeric
+  //
+  // then return failure."
+  if (data.length % 4 === 1 || /[^+/0-9A-Za-z]/.test(data)) {
     return null;
   }
-  // "Let output be a string, initially empty."
-  var output = '';
-  // "Let buffer be a buffer that can have bits appended to it, initially
-  // empty."
+  // "Let output be an empty byte sequence."
+  let output = "";
+  // "Let buffer be an empty buffer that can have bits appended to it."
   //
   // We append bits via left-shift and or.  accumulatedBits is used to track
   // when we've gotten to 24 bits.
-  var buffer = 0;
-  var accumulatedBits = 0;
-  // "While position does not point past the end of input, run these
-  // substeps:"
-  for (var i = 0; i < input.length; i++) {
-    // "Find the character pointed to by position in the first column of
-    // the following table. Let n be the number given in the second cell of
-    // the same row."
+  let buffer = 0;
+  let accumulatedBits = 0;
+  // "Let position be a position variable for data, initially pointing at the
+  // start of data."
+  //
+  // "While position does not point past the end of data:"
+  for (let i = 0; i < data.length; i++) {
+    // "Find the code point pointed to by position in the second column of
+    // Table 1: The Base 64 Alphabet of RFC 4648. Let n be the number given in
+    // the first cell of the same row.
     //
-    // "Append to buffer the six bits corresponding to number, most
-    // significant bit first."
+    // "Append to buffer the six bits corresponding to n, most significant bit
+    // first."
     //
-    // atobLookup() implements the table from the spec.
+    // atobLookup() implements the table from RFC 4648.
     buffer <<= 6;
-    buffer |= atobLookup(input[i]);
-    // "If buffer has accumulated 24 bits, interpret them as three 8-bit
-    // big-endian numbers. Append the three characters with code points
-    // equal to those numbers to output, in the same order, and then empty
-    // buffer."
+    buffer |= atobLookup(data[i]);
     accumulatedBits += 6;
-    if (accumulatedBits == 24) {
+    // "If buffer has accumulated 24 bits, interpret them as three 8-bit
+    // big-endian numbers. Append three bytes with values equal to those
+    // numbers to output, in the same order, and then empty buffer."
+    if (accumulatedBits === 24) {
       output += String.fromCharCode((buffer & 0xff0000) >> 16);
       output += String.fromCharCode((buffer & 0xff00) >> 8);
       output += String.fromCharCode(buffer & 0xff);
       buffer = accumulatedBits = 0;
     }
-    // "Advance position by one character."
+    // "Advance position by 1."
   }
-  // "If buffer is not empty, it contains either 12 or 18 bits. If it
-  // contains 12 bits, discard the last four and interpret the remaining
-  // eight as an 8-bit big-endian number. If it contains 18 bits, discard the
-  // last two and interpret the remaining 16 as two 8-bit big-endian numbers.
-  // Append the one or two characters with code points equal to those one or
-  // two numbers to output, in the same order."
-  if (accumulatedBits == 12) {
+  // "If buffer is not empty, it contains either 12 or 18 bits. If it contains
+  // 12 bits, then discard the last four and interpret the remaining eight as
+  // an 8-bit big-endian number. If it contains 18 bits, then discard the last
+  // two and interpret the remaining 16 as two 8-bit big-endian numbers. Append
+  // the one or two bytes with values equal to those one or two numbers to
+  // output, in the same order."
+  if (accumulatedBits === 12) {
     buffer >>= 4;
     output += String.fromCharCode(buffer);
-  } else if (accumulatedBits == 18) {
+  } else if (accumulatedBits === 18) {
     buffer >>= 2;
     output += String.fromCharCode((buffer & 0xff00) >> 8);
     output += String.fromCharCode(buffer & 0xff);
@@ -89,21 +86,22 @@ function atob(input) {
  */
 function atobLookup(chr) {
   if (/[A-Z]/.test(chr)) {
-    return chr.charCodeAt(0) - 'A'.charCodeAt(0);
+    return chr.charCodeAt(0) - "A".charCodeAt(0);
   }
   if (/[a-z]/.test(chr)) {
-    return chr.charCodeAt(0) - 'a'.charCodeAt(0) + 26;
+    return chr.charCodeAt(0) - "a".charCodeAt(0) + 26;
   }
   if (/[0-9]/.test(chr)) {
-    return chr.charCodeAt(0) - '0'.charCodeAt(0) + 52;
+    return chr.charCodeAt(0) - "0".charCodeAt(0) + 52;
   }
-  if (chr == '+') {
+  if (chr === "+") {
     return 62;
   }
-  if (chr == '/') {
+  if (chr === "/") {
     return 63;
   }
   // Throw exception; should not be hit in tests
+  return undefined;
 }
 
 module.exports = atob;