Add no-observers rule

Author: RobbieTheWagner

config/recommended.js

@@ -83,13 +83,14 @@ module.exports = {
 
     // Ember Suave and Netguru Rules
     'ship-shape/avoid-leaking-state-in-components': 'error',
-    'ship-shape/order-in-components': 'error',
-    'ship-shape/order-in-controllers': 'error',
-    'ship-shape/order-in-models': 'error',
     'ship-shape/no-direct-property-access': 'error',
     'ship-shape/no-empty-attrs': 'error',
+    'ship-shape/no-observers': 'error',
     'ship-shape/no-on-calls-in-components': 'error',
     'ship-shape/no-side-effects': 'error',
+    'ship-shape/order-in-components': 'error',
+    'ship-shape/order-in-controllers': 'error',
+    'ship-shape/order-in-models': 'error',
     'ship-shape/prefer-destructuring': 'error',
     'ship-shape/query-params-on-top': 'error',
     'ship-shape/require-access-in-comments': 'error',

lib/rules/no-observers.js

@@ -0,0 +1,27 @@
+'use strict';
+
+var ember = require('../../lib/utils/ember');
+
+//------------------------------------------------------------------------------
+// General rule - Don't use observers
+//------------------------------------------------------------------------------
+
+module.exports = function(context) {
+
+  var message = 'Don\'t use observers if possible';
+
+  var report = function(node) {
+    context.report(node, message);
+  };
+
+  return {
+    CallExpression: function(node) {
+      var callee = node.callee;
+
+      if(ember.isModule(node, 'observer')) {
+        report(node);
+      }
+    }
+  };
+
+};

tests/lib/rules/no-observers.js

@@ -0,0 +1,35 @@
+'use strict';
+
+// ------------------------------------------------------------------------------
+// Requirements
+// ------------------------------------------------------------------------------
+
+var rule = require('../../../lib/rules/no-observers');
+var RuleTester = require('eslint').RuleTester;
+
+// ------------------------------------------------------------------------------
+// Tests
+// ------------------------------------------------------------------------------
+
+var eslintTester = new RuleTester();
+eslintTester.run('no-observers', rule, {
+  valid: [
+    {
+      code: 'export default Controller.extend();',
+      parserOptions: {ecmaVersion: 6, sourceType: "module"},
+    },
+    {
+      code: 'export default Controller.extend({actions: {},});',
+      parserOptions: {ecmaVersion: 6, sourceType: "module"},
+    }
+  ],
+  invalid: [
+    {
+      code: 'Ember.observer("text", function() {});',
+      parserOptions: {ecmaVersion: 6, sourceType: "module"},
+      errors: [{
+        message: 'Don\'t use observers if possible',
+      }],
+    }
+  ]
+});