fixes #61

README.md

@@ -55,6 +55,12 @@ Default value: `true`
 
 Whether you want to run bower install task itself (e.g. you might not want to do this each time on CI server).
 
+#### options.prune
+Type: `Boolean`
+Default value: `true`
+
+Whether you want to run bower prune task itself (e.g. you might not want to do this each time on CI server).
+
 #### options.cleanTargetDir
 Type: `Boolean`
 Default value: `false`

tasks/bower_task.js

@@ -32,6 +32,15 @@ module.exports = function(grunt) {
     callback();
   }
 
+  function prune(options,callback) {
+    bower.commands.prune([], options.bowerOptions)
+      .on('log', function(result) {
+        log(['bower', result.id.cyan, result.message].join(' '));
+      })
+      .on('error',fail)
+      .on('end',callback);
+  }
+
   function install(options, callback) {
     bower.commands.install([], options.bowerOptions)
       .on('log', function(result) {
@@ -62,6 +71,7 @@ module.exports = function(grunt) {
         targetDir: './lib',
         layout: 'byType',
         install: true,
+        prune: true,
         verbose: false,
         copy: true,
         bowerOptions: {}
@@ -97,6 +107,12 @@ module.exports = function(grunt) {
       });
     }
 
+    if (options.prune) {
+      add('Pruned bower packages', function(callback) {
+        prune(options,callback);
+        });
+    }
+
     if (options.copy) {
       add('Copied packages to ' + targetDir.grey, function(callback) {
         copy(options, callback);