Don't reorder core plugins

Author: giuseppeg

CHANGELOG.md

@@ -1,5 +1,13 @@
 ### HEAD
 
+* Pin core plugins order:
+
+  `postcss-easy-import`
+  [ user plugins ]
+  [ encapsulation plugins ]
+  `autoprefixer`
+  `postcss-reporter`
+* Add experimental `encapsulate` option/feature
 * CLI flags override config file options
 * Input file is now linted (previously only imported files were passed through
   the linting tools)

lib/index.js

@@ -133,9 +133,14 @@ function mergeOptions(options) {
   // but remove any duplicates so that it respects the new order
   if (!isEmpty(options.use)) {
     var plugins = difference(mergedOpts.use, options.use);
-    mergedOpts.use = plugins.concat(options.use);
+    // Remove core plugins. Can't reorder them
+    var userPlugins = difference(options.use, [
+      'postcss-easy-import',
+      'autoprefixer',
+      'postcss-reporter'
+    ]);
+    mergedOpts.use = plugins.concat(userPlugins);
   }
-
   return mergedOpts;
 }
 

test/options.js

@@ -63,7 +63,7 @@ describe('re-ordering the `use` array of postcss plugins', function() {
 
   it('should allow reordering of use array and remove duplicates', function() {
     var opts = mergeOptions({
-      use: ['postcss-at2x', 'postcss-calc']
+      use: ['postcss-at2x', 'postcss-easy-import', 'postcss-calc']
     });
 
     expect(opts.use).to.eql([