removed "use strict"; to avoid influencing not-strict modules

1 files changed, 12 insertions, 4 deletions

diff --git a/lib/rewire.js b/lib/rewire.js
index ae23fb1..2a51e26 100644
--- a/lib/rewire.js
+++ b/lib/rewire.js
@@ -1,9 +1,9 @@
-"use strict"; // run code in ES5 strict mode

-

 var Module = require("module"),

+    fs = require("fs"),

     __get__ = require("./__get__.js"),

     __set__ = require("./__set__.js"),

     getImportGlobalsSrc = require("./getImportGlobalsSrc.js"),

+    detectStrictMode = require("./detectStrictMode.js"),

 

     moduleWrapper0 = Module.wrapper[0], // caching original wrapper

     moduleWrapper1 = Module.wrapper[1], // caching original wrapper

@@ -21,7 +21,8 @@ function rewire(parentModule, filename, cache) {
     var testModule,

         nodeRequire,

         prepend,

-        append;

+        append,

+        src;

 

     /**

      * Proxies the first require call in order to draw back all changes.

@@ -63,7 +64,14 @@ function rewire(parentModule, filename, cache) {
     append = "module.exports.__set__ = " + __set__.toString() + "; ";

     append += "module.exports.__get__ = " + __get__.toString() + "; ";

 

-    // Apply prepend and append

+    // Check if the module uses the strict mode.

+    // If so we must ensure that "use strict"; stays at the beginning of the module.

+    src = fs.readFileSync(filename, "utf8");

+    if (detectStrictMode(src) === true) {

+        prepend = ' "use strict"; ' + prepend;

+    }

+

+    // Apply prepend and appends

     Module.wrapper[0] = moduleWrapper0 + prepend;

     Module.wrapper[1] = append + moduleWrapper1;