feat(promise-helpers): assert that argument is an array

addon/-cancelable-promise-helpers.js

@@ -1,3 +1,4 @@
+import { assert } from '@ember/debug';
 import RSVP, { Promise } from 'rsvp';
 import TaskInstance from './-task-instance';
 import { yieldableSymbol } from './utils';
@@ -23,6 +24,9 @@ function * resolver(value) {
  * [Check out the "Awaiting Multiple Child Tasks example"](/docs/examples/joining-tasks)
  */
 export const all = (things) => {
+  // Extra assertion here to circumvent the `things.length` short circuit.
+  assert(`'all' expects an array.`, Array.isArray(things));
+
   if (things.length === 0) {
     return things;
   }
@@ -105,6 +109,7 @@ function getValues(obj) {
 function taskAwareVariantOf(obj, method, getItems) {
   return function(thing) {
     let items = getItems(thing);
+    assert(`'${method}' expects an array.`, Array.isArray(items));
     let defer = RSVP.defer();
 
     obj[method](thing).then(defer.resolve, defer.reject);

package.json

@@ -48,6 +48,7 @@
     "ember-maybe-import-regenerator": "^0.1.6",
     "ember-notify": "^5.3.0",
     "ember-qunit": "4.1.2",
+    "ember-qunit-assert-helpers": "^0.2.2",
     "ember-resolver": "^4.0.0",
     "ember-sinon": "^2.1.0",
     "ember-source": "~3.6.0",

tests/unit/cancelable-promise-helpers-test.js

@@ -113,6 +113,15 @@ module('Unit: cancelable promises test helpers', function() {
     assert.equal(childTask.get('concurrency'), 0);
   });
 
+  test("all throws an assertion, if something other than an array is passed", function (assert) {
+    assert.expectAssertion(() => {
+      all();
+    }, /'all' expects an array/);
+    assert.expectAssertion(() => {
+      all(RSVP.Promise.resolve());
+    }, /'all' expects an array/);
+  });
+
   test("allSettled behaves like Promise.allSettled", function(assert) {
     assert.expect(6);
 
@@ -230,6 +239,15 @@ module('Unit: cancelable promises test helpers', function() {
     assert.equal(childTask.get('concurrency'), 0);
   });
 
+  test("allSettled throws an assertion, if something other than an array is passed", function (assert) {
+    assert.expectAssertion(() => {
+      allSettled();
+    }, /'allSettled' expects an array/);
+    assert.expectAssertion(() => {
+      allSettled(RSVP.Promise.resolve());
+    }, /'allSettled' expects an array/);
+  });
+
   test("hash", function(assert) {
     assert.expect(1);
 
@@ -308,6 +326,15 @@ module('Unit: cancelable promises test helpers', function() {
     assert.equal(obj.get('child.concurrency'), 0);
   });
 
+  test("race throws an assertion, if something other than an array is passed", function (assert) {
+    assert.expectAssertion(() => {
+      race();
+    }, /'race' expects an array/);
+    assert.expectAssertion(() => {
+      race(RSVP.Promise.resolve());
+    }, /'race' expects an array/);
+  });
+
   test("yieldable helpers work with null/undefined values", function(assert) {
     assert.expect(1);