Custom invalid characters (#57)

README.md

@@ -96,8 +96,11 @@ Sanitize `inputString` by removing or replacing invalid characters.
 
 Options:
 
- * `options.replacement`: *optional, string/function, default: `""`*. If passed
+* `options.replacement`: *optional, string/function, default: `""`*. If passed
  as a string, it's used as the replacement for invalid characters. If passed as
  a function, the function will be called with the invalid characters and it's
  return value will be used as the replacement. See [`String.prototype.replace`](https://developer.mozilla.org/en-US/docs/Web/JavaScript/Reference/Global_Objects/String/replace)
  for more info.
+* `options.additionalInvalids`: *optional, array of strings, default:* `[]`  
+  Any additional strings or characters that should be considered invalid and be replaced. This will not override the default invalid characters, only specify additional ones.  
+  If a string containing a mix of valid and invalid characters is supplied, all occurences of the whole string will be replaced.

index.d.ts

@@ -2,6 +2,7 @@ declare function sanitize(
   input: string,
   options?: {
     replacement?: string | ((substring: string) => string);
+    additionalInvalids?: string[];
   }
 ): string;
 

index.js

@@ -5,6 +5,7 @@
  * Replaces characters in strings that are illegal/unsafe for filenames.
  * Unsafe characters are either removed or replaced by a substitute set
  * in the optional `options` object.
+ * Additionally, more invalid characters can be passed using the `additionalInvalids` attribute of the optional `options` object.
  *
  * Illegal Characters on Various Operating Systems
  * / ? < > \ : * | "
@@ -24,7 +25,7 @@
  * http://unix.stackexchange.com/questions/32795/what-is-the-maximum-allowed-filename-and-folder-size-with-ecryptfs
  *
  * @param  {String} input   Original filename
- * @param  {Object} options {replacement: String | Function }
+ * @param  {Object} options {replacement: String | Function, additionalInvalids: String[] }
  * @return {String}         Sanitized filename
  */
 
@@ -36,11 +37,26 @@ var reservedRe = /^\.+$/;
 var windowsReservedRe = /^(con|prn|aux|nul|com[0-9]|lpt[0-9])(\..*)?$/i;
 var windowsTrailingRe = /[\. ]+$/;
 
-function sanitize(input, replacement) {
+function sanitize(input, replacement, invalids) {
   if (typeof input !== 'string') {
     throw new Error('Input must be string');
   }
-  var sanitized = input
+  if (typeof replacement === 'string' && invalids.indexOf(replacement) !== -1) {
+    throw new Error(`The replacement string can't be part of options.additionalInvalids or contain substrings which are part of options.additionalInvalids!`);
+  }
+  var sanitized = input;
+  while (invalids.some(invalid => sanitized.includes(invalid))) {
+    let counter = 0;
+    for (const invalid of invalids) {
+      sanitized = sanitized.split(invalid).join(replacement);
+    }
+    if (counter > 1000) {
+      throw new Error(`Illeagal replacement function. Make sure that replacements generated by your function do not contain any of the strings specified in options.additionalInvalids!`);
+    } else {
+      counter++;
+    }
+  }
+  sanitized = sanitized
     .replace(illegalRe, replacement)
     .replace(controlRe, replacement)
     .replace(reservedRe, replacement)
@@ -51,9 +67,10 @@ function sanitize(input, replacement) {
 
 module.exports = function (input, options) {
   var replacement = (options && options.replacement) || '';
-  var output = sanitize(input, replacement);
+  var invalids = (options && options.additionalInvalids) || [];
+  var output = sanitize(input, replacement, invalids);
   if (replacement === '') {
     return output;
   }
-  return sanitize(output, '');
+  return sanitize(output, '', []);
 };