Add --cov code coverage option

1 files changed, 16 insertions, 0 deletions

diff --git a/lib/module.js b/lib/module.js
index d806a4ae82..308fd4e8e3 100644
--- a/lib/module.js
+++ b/lib/module.js
@@ -347,6 +347,22 @@ Module.prototype._compile = function(content, filename) {
   // remove shebang
   content = content.replace(/^\#\!.*/, '');
 
+  // add coverage
+  if (process.cov) {
+    var lines = content.split('\n');
+
+    if (lines.length > 0) {
+      lines[0] = '__cov[__filename] = { 0: true}; ' + lines[0];
+    }
+
+    for (var i = 0; i < lines.length; i++) {
+      lines[i] =
+        lines[i].replace(/;$/, '; __cov[__filename][' + i + '] = true;');
+    }
+
+    content = lines.join('\n');
+  }
+
   function require(path) {
     return Module._load(path, self);
   }