add context to replace function

Author: smartin85

README.md

@@ -133,7 +133,10 @@ module.exports = {
         loader: 'string-replace-loader',
         options: {
           search: '^Hello, (.*)!$',
-          replace: (match, p1, offset, string) => `Bonjour, ${p1.toUpperCase()}!`,
+          replace(match, p1, offset, string) {
+            console.log(`Replace "${match}" in file "${this.resource}".`)
+            return `Bonjour, ${p1.toUpperCase()}!`
+          },
           flags: 'g'
         }
       }

lib/processChunk.js

@@ -8,7 +8,7 @@ function processChunk (source, map) {
   let newSource = source
 
   for (const options of optionsArray) {
-    newSource = replace(newSource, options)
+    newSource = replace(newSource, options, this)
   }
 
   this.callback(null, newSource, map)

lib/replace.js

@@ -1,5 +1,5 @@
 
-function replace (source, options) {
+function replace (source, options, context) {
   const { replace, flags, strict } = options
   let search
   if (options.search instanceof RegExp) {
@@ -15,7 +15,7 @@ function replace (source, options) {
     throw new Error('Replace failed (strict mode) : options.search and options.replace are required')
   }
 
-  const newSource = source.replace(search, replace)
+  const newSource = source.replace(search, typeof replace === 'function' ? replace.bind(context) : replace)
 
   if (strict && (newSource === source)) {
     throw new Error('Replace failed (strict mode) : ' + options.search + ' → ' + options.replace)