Added strict mode

README.md

@@ -87,6 +87,31 @@ module.exports = {
 }
 ```
 
+### Strict mode replacement:
+
+You can set strict mode to ensure that the replacement was done:
+
+In your `webpack.config.js`:
+
+```javascript
+module.exports = {
+  // ...
+  module: {
+    loaders: [
+      {
+        test: /fileInWhichJQueryIsUndefined\.js$/,
+        loader: 'string-replace',
+        query: {
+          search: 'jQuery',
+          replace: 'window.$',
+          strict: true
+        }
+      }
+    ]
+  }
+}
+```
+
 ## Contributing:
 
 Feel free to open issues to propose stuff and participate. Pull requests are also welcome.

index.js

@@ -7,10 +7,21 @@ function processOptions(source, options) {
       options.search = new RegExp(options.search, options.flags);
     }
 
-    source = source.replace(options.search, options.replace);
+    newSource = source.replace(options.search, options.replace);
+    if (options.strict === true && newSource === source) {
+      throw new Error('Cannot replace ' + options.search + ' → ' + options.replace);
+    }
   }
 
-  return source;
+  if (options.strict === true && _.isUndefined(options.search)) {
+    throw new Error('Cannot replace: search option is not defined → ' + JSON.stringify(options));
+  }
+
+  if (options.strict === true && _.isUndefined(options.replace)) {
+    throw new Error('Cannot replace: replace option is not defined → ' + JSON.stringify(options));
+  }
+
+  return newSource;
 }
 
 module.exports = function (source) {
@@ -20,6 +31,7 @@ module.exports = function (source) {
 
   if (_.isArray(options.multiple)) {
     options.multiple.forEach(function (suboptions) {
+      suboptions.strict = !_.isUndefined(suboptions.strict) ? suboptions.strict : options.strict;
       source = processOptions(source, suboptions);
     });
   } else {