DEV: Add remove button function to PluginAPI (#9627)

test/javascripts/widgets/post-menu-test.js

@@ -0,0 +1,44 @@
+import { moduleForWidget, widgetTest } from "helpers/widget-test";
+import { withPluginApi } from "discourse/lib/plugin-api";
+
+moduleForWidget("post-menu");
+
+widgetTest("add extra button", {
+  template: '{{mount-widget widget="post-menu" args=args}}',
+  beforeEach() {
+    this.set("args", {});
+    withPluginApi("0.8", api => {
+      api.addPostMenuButton("coffee", () => {
+        return {
+          action: "drinkCoffee",
+          icon: "coffee",
+          className: "hot-coffee",
+          title: "coffee.title",
+          position: "first"
+        };
+      });
+    });
+  },
+  async test(assert) {
+    assert.ok(
+      find(".actions .extra-buttons .hot-coffee").length === 1,
+      "It renders extra button"
+    );
+  }
+});
+
+widgetTest("remove extra button", {
+  template: '{{mount-widget widget="post-menu" args=args}}',
+  beforeEach() {
+    this.set("args", {});
+    withPluginApi("0.8", api => {
+      api.removePostMenuButton("coffee");
+    });
+  },
+  async test(assert) {
+    assert.ok(
+      find(".actions .extra-buttons .hot-coffee").length === 0,
+      "It doesn't removes coffee button"
+    );
+  }
+});