FIX: `expandAllPinned` was not resetting after visiting a category

This resulted in a bug where if you saw a pinned topic in a category,
then went back to latest, the same topic would show an excerpt even
though it shouldn't on the latest view.

See:
https://meta.discourse.org/t/pinned-post-excerpt-no-longer-appears-after-refreshing-the-page/106222

.eslintrc

@@ -62,6 +62,7 @@
     "triggerEvent": true,
     "visible": true,
     "visit": true,
+    "pauseTest": true
   },
   "rules": {
     "block-scoped-var": 2,

app/assets/javascripts/discourse/routes/build-topic-route.js.es6

@@ -113,6 +113,7 @@ export default function(filter, extras) {
             model.get("for_period") ||
             (filter.indexOf("top/") >= 0 ? filter.split("/")[1] : ""),
           selected: [],
+          expandAllPinned: false,
           expandGloballyPinned: true
         };
 

test/javascripts/acceptance/topic-discovery-test.js.es6

@@ -1,5 +1,9 @@
 import { acceptance } from "helpers/qunit-helpers";
-acceptance("Topic Discovery");
+acceptance("Topic Discovery", {
+  settings: {
+    show_pinned_excerpt_desktop: true
+  }
+});
 
 QUnit.test("Visit Discovery Pages", async assert => {
   await visit("/");
@@ -59,3 +63,16 @@ QUnit.test("Visit Discovery Pages", async assert => {
     "The featured topics are there too"
   );
 });
+
+QUnit.test("Clearing state after leaving a category", async assert => {
+  await visit("/c/dev");
+  assert.ok(
+    exists(".topic-list-item[data-topic-id=11994] .topic-excerpt"),
+    "it expands pinned topics in a subcategory"
+  );
+  await visit("/");
+  assert.ok(
+    !exists(".topic-list-item[data-topic-id=11557] .topic-excerpt"),
+    "it doesn't expand all pinned in the latest category"
+  );
+});

test/javascripts/fixtures/discovery_fixtures.js.es6

@@ -4962,7 +4962,8 @@ export default {
           bumped: true,
           bumped_at: "2014-01-16T11:04:32.000-05:00",
           unseen: false,
-          pinned: false,
+          pinned: true,
+          excerpt: "Hello world",
           visible: true,
           closed: false,
           archived: false,