chore: Refactor backlinks and revisions (#1611)

* Update backlinks service to not rely on revisions

* fix: Add missing index for finding backlinks

* Debounce revision creation (#1616)

* refactor debounce logic to service

* Debounce slack notification

* Revisions created by service

* fix: Revision sidebar latest

* test: Add tests for notifications

server/services/notifications.test.js

@@ -0,0 +1,87 @@
+/* eslint-disable flowtype/require-valid-file-annotation */
+import mailer from "../mailer";
+import { View, NotificationSetting } from "../models";
+import { buildDocument, buildUser } from "../test/factories";
+import { flushdb } from "../test/support";
+import NotificationsService from "./notifications";
+
+jest.mock("../mailer");
+
+const Notifications = new NotificationsService();
+
+beforeEach(() => flushdb());
+beforeEach(jest.resetAllMocks);
+
+describe("documents.update.debounced", () => {
+  test("should send a notification to other collaborator", async () => {
+    const document = await buildDocument();
+    const collaborator = await buildUser({ teamId: document.teamId });
+    document.collaboratorIds = [collaborator.id];
+    await document.save();
+
+    await NotificationSetting.create({
+      userId: collaborator.id,
+      teamId: collaborator.teamId,
+      event: "documents.update",
+    });
+
+    await Notifications.on({
+      name: "documents.update.debounced",
+      documentId: document.id,
+      collectionId: document.collectionId,
+      teamId: document.teamId,
+      actorId: document.createdById,
+    });
+
+    expect(mailer.documentNotification).toHaveBeenCalled();
+  });
+
+  test("should not send a notification if viewed since update", async () => {
+    const document = await buildDocument();
+    const collaborator = await buildUser({ teamId: document.teamId });
+    document.collaboratorIds = [collaborator.id];
+    await document.save();
+
+    await NotificationSetting.create({
+      userId: collaborator.id,
+      teamId: collaborator.teamId,
+      event: "documents.update",
+    });
+
+    await View.touch(document.id, collaborator.id, true);
+
+    await Notifications.on({
+      name: "documents.update.debounced",
+      documentId: document.id,
+      collectionId: document.collectionId,
+      teamId: document.teamId,
+      actorId: document.createdById,
+    });
+
+    expect(mailer.documentNotification).not.toHaveBeenCalled();
+  });
+
+  test("should not send a notification to last editor", async () => {
+    const user = await buildUser();
+    const document = await buildDocument({
+      teamId: user.teamId,
+      lastModifiedById: user.id,
+    });
+
+    await NotificationSetting.create({
+      userId: user.id,
+      teamId: user.teamId,
+      event: "documents.update",
+    });
+
+    await Notifications.on({
+      name: "documents.update.debounced",
+      documentId: document.id,
+      collectionId: document.collectionId,
+      teamId: document.teamId,
+      actorId: document.createdById,
+    });
+
+    expect(mailer.documentNotification).not.toHaveBeenCalled();
+  });
+});