add some docs about .debug()

Author: machty

addon/-task-property.js

@@ -514,6 +514,28 @@ objectAssign(TaskProperty.prototype, propertyModifiers, {
    * @param {Number} n The maximum number of concurrently running tasks
    * @instance
    */
+
+  /**
+   * Adds this task to a TaskGroup so that concurrency constraints
+   * can be shared between multiple tasks.
+   *
+   * [See the Task Group docs for more information](/#/docs/task-groups)
+   *
+   * @method group
+   * @memberof TaskProperty
+   * @param {String} groupPath A path to the TaskGroup property
+   * @instance
+   */
+
+  /**
+   * Logs lifecycle events to aid in debugging unexpected Task behavior.
+   * Presently only logs cancelation events and the reason for the cancelation,
+   * e.g. "TaskInstance 'doStuff' was canceled because the object it lives on was destroyed or unrendered"
+   *
+   * @method debug
+   * @memberof TaskProperty
+   * @instance
+   */
 });
 
 function defaultDebugCallback(payload) {

tests/dummy/app/docs/testing-debugging/template.hbs

@@ -121,3 +121,19 @@
   functions (Chrome's implementation only became spec-compliant around June, 2016).
 </p>
 
+<h4>Unexpected Cancelation</h4>
+
+<p>
+  Sometimes it's not obvious why a Task was canceled; in these cases you
+  can use the <code>.debug()</code> Task Modifier on a specific task e.g.
+  <code>nameOfTask: task(...).debug()</code>,
+  which will provide some logging about the task's lifecycle, e.g.
+  <code>TaskInstance 'nameOfTask' was canceled because the object it lives on was destroyed or unrendered </code>.
+</p>
+
+<p>
+  To enable lifecycle logging on ALL ember-concurrency tasks, you can enable the <code>DEBUG_TASKS</code>
+  flag on <code>EmberENV</code> in your project's <code>config/environment.js</code> file.
+</p>
+
+