Fixing the imports stored for cache invalidation to have the path and mtime again.

Closes #123

Author: Zoramite

lib/middleware.js

@@ -196,10 +196,30 @@ module.exports = less.middleware = function(source, options){
                 return next(err);
               }
 
+              // Determine the imports used and check modified times.
+              var imports = [];
+              output.imports.forEach(function(imported) {
+                var currentImport = {
+                    path: imported,
+                    mtime: null
+                };
+
+                imports.push(currentImport);
+
+                // Update the mtime of the import async.
+                fs.stat(imported, function(err, lessStats){
+                  if (err) {
+                    return error(err);
+                  }
+
+                  currentImport.mtime = lessStats.mtime;
+                });
+              });
+
               // Store the less paths for simple cache invalidation.
               lessFiles[lessPath] = {
                 mtime: Date.now(),
-                imports: output.imports
+                imports: imports
               };
 
               if(output.map) {

test/fixtures/cacheFile-exp.json

@@ -1,9 +1,18 @@
 {
    "{$}/import.less": {
       "imports": [
-         "{$}/import-header.less",
-         "{$}/import-widget.less",
-         "{$}/import-color.less"
+        {
+          "path": "{$}/import-header.less",
+          "mtime": null
+        },
+        {
+          "path": "{$}/import-widget.less",
+          "mtime": null
+        },
+        {
+          "path": "{$}/import-color.less",
+          "mtime": null
+        }
       ]
    }
 }

test/fixtures/cacheFile-exp2.json

@@ -1,7 +1,10 @@
 {
    "{$}/import.less": {
       "imports": [
-         "{$}/import-color.less"
+        {
+          "path": "{$}/import-color.less",
+          "mtime": null
+        }
       ]
    }
 }

test/test-middleware.js

@@ -202,6 +202,14 @@ describe('middleware', function(){
     }
 
     var checkCacheFile = function(cacheFile, expectedFile){
+      var sortByPath = function(a, b) {
+        var keyA = a.path;
+        var keyB = b.path;
+        if(keyA < keyB) return -1;
+        if(keyA > keyB) return 1;
+        return 0;
+      };
+
       return function(){
         // Force cacheFile write.
         middleware._saveCacheToFile();
@@ -212,13 +220,13 @@ describe('middleware', function(){
         for (var file in cacheFileExpected) {
           assert(cacheFileOutput[file] != undefined);
 
-          var expectedImports = cacheFileExpected[file].imports.sort();
-          var outputImports = cacheFileOutput[file].imports.sort();
+          var expectedImports = cacheFileExpected[file].imports.sort(sortByPath);
+          var outputImports = cacheFileOutput[file].imports.sort(sortByPath);
 
           assert.equal(outputImports.length, expectedImports.length);
 
           for (var i = 0; i < expectedImports.length; i++) {
-            assert.equal(expectedImports[i], outputImports[i]);
+            assert.equal(expectedImports[i].path, outputImports[i].path);
           }
         }
       }