DEV: Add test for opening drafts from Activity screen (#8401)

Follow-up to 520d54d85f.

test/javascripts/acceptance/user-drafts-stream-test.js.es6

@@ -12,3 +12,11 @@ QUnit.test("Stream", async assert => {
     "draft removed, list length diminished by one"
   );
 });
+
+QUnit.test("Stream - resume draft", async assert => {
+  await visit("/u/eviltrout/activity/drafts");
+  assert.ok(find(".user-stream-item").length > 0, "has drafts");
+
+  await click(".user-stream-item .resume-draft");
+  assert.equal(find(".d-editor-input").val(), "dum de dum da ba.");
+});