Tweaks to readme

README.md

@@ -198,7 +198,7 @@ You can also specify a callback that returns a string or a regular expression. T
 ```js
 const options = {
   files: 'path/to/file',
-  from: (file) => RegExp(`${foo('SomePattern[A-Za-z-]+', file)}`, g);,
+  from: (file) => new RegExp(file, 'g'),
   to: 'bar',
 };
 ```
@@ -220,10 +220,7 @@ This callback provides for an extra argument above the String replace method, wh
 const options = {
   files: 'path/to/file',
   from: /SomePattern[A-Za-z-]+/g,
-  to: (...args)  => {
-    const file = args.pop();
-    return file;
-  },
+  to: (...args) => args.pop(),
 };
 ```
 

lib/helpers/make-replacements.js

@@ -28,8 +28,8 @@ module.exports = function makeReplacements(contents, from, to, file) {
 
   //Make replacements
   from.forEach((item, i) => {
-    //`from` callback is called with a filename argument
-    //and returns string or regexp
+
+    //Call function if given, passing the filename
     if (typeof item === 'function') {
       item = item(file);
     }
@@ -39,9 +39,10 @@ module.exports = function makeReplacements(contents, from, to, file) {
     if (replacement === null) {
       return;
     }
+
+    //Call function if given, appending the filename
     if (typeof replacement === 'function') {
       const original = replacement;
-      //`to` callback is called with an additional filename argument
       replacement = (...args) => original(...args, file);
     }