Merge pull request #93 from universal-ember/thennable-trackedTask

Make trackedTask reactively thennable, so that integrations with thennables are automatically reactive

reactiveweb/src/ember-concurrency.ts

@@ -157,11 +157,16 @@ export class State<Args extends any[], Return, LocalTask extends TaskIsh<Args, R
 
         if (key === 'value') {
           /**
-           * getter than falls back to the previous task's value
+           * getter that falls back to the previous task's value
            */
           return taskRunner.value;
         }
 
+        // We can be thennable, but we'll want to entangle with tracked data
+        if (key === 'then') {
+          get(taskRunner.currentTask, 'isRunning');
+        }
+
         /**
          * If the key is anything other than value, query on the currentTask
          */

tests/test-app/tests/utils/ember-concurrency/rendering-test.gts

@@ -7,6 +7,7 @@ import { setupRenderingTest } from 'ember-qunit';
 
 import { restartableTask, timeout } from 'ember-concurrency';
 import { trackedTask } from 'reactiveweb/ember-concurrency';
+import { trackedFunction } from 'reactiveweb/function';
 
 let version = '^3.0.0';
 
@@ -71,6 +72,47 @@ module('useTask', function () {
       window.onerror = onError;
     });
 
+    test('is reactively thennable', async function (assert) {
+      class Test {
+        @tracked input = 'Hello there';
+
+        _search = restartableTask(async (input: string) => {
+          await timeout(100);
+          assert.step('resolved rt');
+
+          return input;
+        });
+        search = trackedTask(this, this._search, () => [this.input]);
+
+        wrappedSearch = trackedFunction(this, async () => {
+          let result = await this.search;
+
+          assert.step(`tf:${result}`);
+
+          return String(result);
+        });
+      }
+
+      let ctx = new Test();
+
+      render(<template>{{ctx.wrappedSearch.value}}</template>);
+
+      // This could introduce flakiness / timing issues
+      await timeout(10);
+
+      assert.dom().hasNoText();
+
+      await settled();
+
+      assert.dom().hasText('Hello there');
+      assert.verifySteps(['resolved rt', 'tf:Hello there', 'tf:Hello there'], 'tracked function over-dirties due to consuming a task');
+
+      ctx.input = 'General Kenobi';
+      await settled();
+      assert.dom().hasText('General Kenobi');
+      assert.verifySteps(['resolved rt', 'tf:General Kenobi', 'tf:General Kenobi'], 'tracked function over-dirties due to consuming a task');
+    });
+
     test('error', async function (assert) {
       setupOnerror((error: any) => {
         assert.ok(