Merge pull request #11466 from stefanpenner/fix-should-display

[Bugfix beta] ensure isTruthy is only attempted if the predicate is a…

packages/ember-metal/lib/computed.js

@@ -534,7 +534,7 @@ ComputedPropertyPrototype.teardown = function(obj, keyName) {
   @return {Ember.ComputedProperty} property descriptor instance
   @public
 */
-function computed(func) {
+export default function computed(func) {
   var args;
 
   if (arguments.length > 1) {

packages/ember-views/lib/streams/should_display.js

@@ -10,8 +10,16 @@ export default function shouldDisplay(predicate) {
     return new ShouldDisplayStream(predicate);
   }
 
-  var truthy = predicate && get(predicate, 'isTruthy');
-  if (typeof truthy === 'boolean') { return truthy; }
+  var type = typeof predicate;
+
+  if (type === 'boolean') { return predicate; }
+
+  if (type && type === 'object') {
+    var isTruthy = get(predicate, 'isTruthy');
+    if (typeof isTruthy === 'boolean') {
+      return isTruthy;
+    }
+  }
 
   if (isArray(predicate)) {
     return get(predicate, 'length') !== 0;

packages/ember-views/tests/streams/streams-test.js

@@ -0,0 +1,55 @@
+import shouldDisplay from 'ember-views/streams/should_display';
+import { defineProperty } from 'ember-metal/properties';
+import computed from 'ember-metal/computed';
+
+QUnit.module('shouldDisplay');
+
+QUnit.test('predicate permutations', function() {
+  equal(shouldDisplay(0), false, 'shouldDisplay(0)');
+  equal(shouldDisplay(-1), true, 'shouldDisplay(-1)');
+  equal(shouldDisplay(1), true, 'shouldDisplay(1)');
+  equal(shouldDisplay(Number(1)), true, 'shouldDisplay(Number(1))');
+  equal(shouldDisplay(Number(0)), false, 'shouldDisplay(Number(0))');
+  equal(shouldDisplay(Number(-1)), true, 'shouldDisplay(Number(-1))');
+  equal(shouldDisplay(Boolean(true)), true, 'shouldDisplay(Boolean(true))');
+  equal(shouldDisplay(Boolean(false)), false, 'shouldDisplay(Boolean(false))');
+  equal(shouldDisplay(NaN), false, 'shouldDisplay(NaN)');
+  equal(shouldDisplay('string'), true, 'shouldDisplay("string")');
+  equal(shouldDisplay(String('string')), true, 'shouldDisplay(String("string"))');
+  equal(shouldDisplay(Infinity), true, 'shouldDisplay(Infinity)');
+  equal(shouldDisplay(-Infinity), true, 'shouldDisplay(-Infinity)');
+  equal(shouldDisplay([]), false, 'shouldDisplay([])');
+  equal(shouldDisplay([1]), true, 'shouldDisplay([1])');
+  equal(shouldDisplay({}), true, 'shouldDisplay({})');
+  equal(shouldDisplay(true), true, 'shouldDisplay(true)');
+  equal(shouldDisplay(false), false, 'shouldDisplay(false)');
+  equal(shouldDisplay({ isTruthy: true }), true, 'shouldDisplay({ isTruthy: true })');
+  equal(shouldDisplay({ isTruthy: false }), false, 'shouldDisplay({ isTruthy: false })');
+
+  equal(shouldDisplay(function foo() {}), true, 'shouldDisplay(function (){})');
+
+  function falseFunction() { }
+  falseFunction.isTruthy = false;
+
+  equal(shouldDisplay(falseFunction), true, 'shouldDisplay(function.isTruthy = false)');
+
+  function trueFunction() { }
+  falseFunction.isTruthy = true;
+  equal(shouldDisplay(trueFunction), true, 'shouldDisplay(function.isTruthy = true)');
+
+  var truthyObj = { };
+  defineProperty(truthyObj, 'isTruthy', computed(() => true));
+  equal(shouldDisplay(truthyObj), true, 'shouldDisplay(obj.get("isTruthy") === true)');
+
+  var falseyObj = { };
+  defineProperty(falseyObj, 'isTruthy', computed(() => false));
+  equal(shouldDisplay(falseyObj), false, 'shouldDisplay(obj.get("isFalsey") === false)');
+
+  var falsyArray = [1];
+  falsyArray.isTruthy = false;
+  equal(shouldDisplay(falsyArray), false, '[1].isTruthy = false');
+
+  var falseyCPArray = [1];
+  defineProperty(falseyCPArray, 'isTruthy', computed(() => false));
+  equal(shouldDisplay(falseyCPArray), false, 'shouldDisplay([1].get("isFalsey") === true');
+});