barebones

.eslintrc.js

@@ -1,5 +1,6 @@
 module.exports = {
   root: true,
+  parser: "babel-eslint",
   parserOptions: {
     ecmaVersion: 2017,
     sourceType: 'module'

README.md

@@ -1,9 +1,84 @@
 # ember-concurrency-decorators
 
-This README outlines the details of collaborating on this Ember addon.
+## EXPERIMENTAL
+
+Babel support for decorator syntax has been fidgety, so expect a bit
+of a bumpy ride. Also, the API of this addon is still pre-Alpha.
+Probably don't use this in prod code.
+
+## Overview
+
+This Ember Addon let's you use the
+[decorator syntax](https://github.com/tc39/proposal-decorators)
+for declaring/configuring
+[ember-concurrency](https://ember-concurrency.com) tasks.
+
+Classic syntax (without decorators):
+
+```js
+import { task } from 'ember-concurrency';
+export default Ember.Component.extend({
+  doStuff: task(function * () {
+    // ...
+  }).restartable()
+});
+
+// elsewhere:
+this.get('doStuff').perform();
+```
+
+With decorator syntax
+
+```js
+import { restartableTask } from 'ember-concurrency-decorators';
+export default Ember.Component.extend({
+  @restartableTask
+  doStuff: function * () {
+    // ...
+  }
+});
+
+// elsewhere:
+this.get('doStuff').perform();
+// `doStuff` is still a Task object that can be `.perform()`ed
+```
+
+There's actually an even nicer syntax that's on the horizon, but
+is NOT YET SUPPORTED due to a [Babel bug](https://github.com/babel/babylon/issues/13).
+
+```js
+export default Ember.Component.extend({
+  // THIS SYNTAX IS NOT YET SUPPORTED, BUT SOON!
+  @restartableTask
+  *doStuff() {
+    // ...
+  }
+});
+```
+
+When this Babel issue is addressed, this syntax should Just Work with
+this addon.
 
 ## Installation
 
+```
+ember install ember-concurrency-decorators
+npm install --save babel-plugin-transform-decorators-legacy
+```
+
+Then you'll need to enable the decorator transpilation plugin in your
+`ember-cli-build.js` file:
+
+```
+  var app = new EmberApp({
+    babel: {
+      plugins: ['transform-decorators-legacy']
+    }
+  });
+```
+
+## Working on this repo
+
 * `git clone <repository-url>` this repository
 * `cd ember-concurrency-decorators`
 * `npm install`

addon/index.js

@@ -0,0 +1,54 @@
+import { task as ecTask } from 'ember-concurrency';
+
+function extractValue(desc) {
+  return desc.value ||
+    (typeof desc.initializer === 'function' && desc.initializer());
+}
+
+function isDescriptor(item) {
+  return item &&
+    typeof item === 'object' &&
+    'writable' in item &&
+    'enumerable' in item &&
+    'configurable' in item;
+}
+
+function handleDescriptor(callback, target, key, desc, params = []) {
+  return {
+    enumerable: desc.enumerable,
+    configurable: desc.configurable,
+    writeable: desc.writeable,
+    initializer: function() {
+      if (!desc.writable) {
+        throw new Error('ember-concurrency-decorators does not support using getters and setters');
+      }
+
+      let value = extractValue(desc);
+      return callback(value, params);
+    }
+  };
+}
+
+function decorator(callback) {
+  return function(...params) {
+    // determine if user called as @task('blah', 'blah') or @task
+    if (isDescriptor(params[params.length - 1])) {
+      return handleDescriptor(callback, ...arguments);
+    } else {
+      return function(/* target, key, desc */) {
+        return handleDescriptor(callback, ...arguments, params);
+      };
+    }
+  };
+}
+
+
+function taskify(value) {
+  return (typeof value === 'function') ? ecTask(value) : value;
+}
+
+export const task = decorator(v => taskify(v));
+export const restartableTask = decorator(v => taskify(v).restartable());
+export const dropTask = decorator(v => taskify(v).drop());
+export const keepLatestTask = decorator(v => taskify(v).keepLatest());
+export const enqueueTask = decorator(v => taskify(v).enqueue());

ember-cli-build.js

@@ -3,7 +3,9 @@ const EmberAddon = require('ember-cli/lib/broccoli/ember-addon');
 
 module.exports = function(defaults) {
   var app = new EmberAddon(defaults, {
-    // Add options here
+    babel: {
+      plugins: ['transform-decorators-legacy']
+    }
   });
 
   /*

package.json

@@ -1,6 +1,6 @@
 {
   "name": "ember-concurrency-decorators",
-  "version": "0.0.0",
+  "version": "0.0.1",
   "description": "The default blueprint for ember-cli addons.",
   "keywords": [
     "ember-addon"
@@ -21,6 +21,8 @@
     "ember-cli-babel": "^6.0.0"
   },
   "devDependencies": {
+    "babel-eslint": "^7.2.3",
+    "babel-plugin-transform-decorators-legacy": "^1.3.4",
     "broccoli-asset-rev": "^2.4.5",
     "ember-ajax": "^3.0.0",
     "ember-cli": "2.13.1",
@@ -33,6 +35,7 @@
     "ember-cli-shims": "^1.1.0",
     "ember-cli-sri": "^2.1.0",
     "ember-cli-uglify": "^1.2.0",
+    "ember-concurrency": "^0.8.2",
     "ember-disable-prototype-extensions": "^1.1.0",
     "ember-export-application-global": "^2.0.0",
     "ember-load-initializers": "^1.0.0",

tests/unit/decorators-test.js

@@ -0,0 +1,46 @@
+/*eslint-disable*/
+
+import Ember from 'ember';
+import { timeout } from 'ember-concurrency';
+import {
+  task,
+  restartableTask,
+  dropTask,
+  keepLatestTask,
+  enqueueTask,
+  maxConcurrency
+} from 'ember-concurrency-decorators';
+import { module, test } from 'qunit';
+
+module('Unit: decorators');
+
+test("a plethora of decorators", function(assert) {
+  assert.expect(1);
+
+  let Obj = Ember.Object.extend({
+    @task
+    doStuff: function * () {
+      return 123;
+    },
+
+    @restartableTask
+    a: function * () { },
+
+    @keepLatestTask
+    b: function * () { },
+
+    @dropTask
+    c: function * () { },
+
+    @enqueueTask
+    d: function * () { },
+  });
+
+  let obj;
+  Ember.run(() => {
+    obj = Obj.create();
+    obj.get('doStuff').perform();
+  });
+  assert.equal(obj.get('doStuff.last.value'), 123);
+});
+