Close #323 PR: fix #307 - grunt-watch spawn:false compatibility fix.

lib/configwriter.js

@@ -6,8 +6,22 @@ var _ = require('lodash');
 var deepMerge = function (origCfg, cfg) {
   var outCfg = origCfg;
 
+// If the newly generated part is already in the config file
+// with the same destination update only the source part, instead of add the whole block again.
+// This way the same targets wont be regenerated multiple times if usemin is called
+// multiple times which can happen with grunt-watcher spawn:false mode (#307)
+
   if (origCfg.files && cfg.files) {
-    outCfg.files = _.union(origCfg.files, cfg.files);
+    var done = false;
+    for (var i = 0; i < origCfg.files.length; i++) {
+      if (outCfg.files[i].dest === cfg.files[0].dest) {
+        outCfg.files[i].src = cfg.files[0].src;
+        done = true;
+      }
+    }
+    if (!done) {
+      outCfg.files = _.union(origCfg.files, cfg.files);
+    }
   } else if (cfg.files) {
     outCfg.files = cfg.files;
   }

test/test-config-writer.js

@@ -402,5 +402,24 @@ describe('ConfigWriter', function () {
         assert.deepEqual(names, ['concat', 'uglify']);
       });
     });
+
+    it('should not add the same block multiple times though we call process() explicitly 2 times.', function () {
+      var flow = new Flow({steps: {js: ['concat', 'uglifyjs']}});
+
+      var file = helpers.createFile('foo', 'app', blocks);
+      var c = new ConfigWriter(flow, {input: 'app', dest: 'destination', staging: '.tmp'});
+      var config = c.process(file);
+      config = c.process(file, config);  // This second process is intentional. Details are in issue #307.
+      var expected = helpers.normalize({
+        concat: {generated: {files: [
+          {dest: '.tmp/concat/scripts/site.js', src: ['app/foo.js', 'app/bar.js', 'app/baz.js']}
+        ]}},
+        uglify: {generated: {files: [
+          {dest: 'destination/scripts/site.js', src: ['.tmp/concat/scripts/site.js']}
+        ]}}
+      });
+
+      assert.deepEqual(config, expected);
+    });
   });
 });