fix: Attachments should not always be deleted with their original document (#1715)

* fix: Attachments should not be deleted when their original document is deleted when referenced elsewhere

* fix: Attachments deleted prematurely when docs are placed in trash

* mock

* restore hook, cascading delete was the issue

server/api/utils.js

@@ -4,44 +4,80 @@ import debug from "debug";
 import Router from "koa-router";
 import { AuthenticationError } from "../errors";
 import { Document, Attachment } from "../models";
-import { Op } from "../sequelize";
+import { Op, sequelize } from "../sequelize";
+import parseAttachmentIds from "../utils/parseAttachmentIds";
 
 const router = new Router();
 const log = debug("utils");
 
 router.post("utils.gc", async (ctx) => {
-  const { token } = ctx.body;
+  const { token, limit = 500 } = ctx.body;
 
   if (process.env.UTILS_SECRET !== token) {
     throw new AuthenticationError("Invalid secret token");
   }
 
-  log("Permanently deleting documents older than 30 days…");
-
-  const where = {
-    deletedAt: {
-      [Op.lt]: subDays(new Date(), 30),
-    },
-  };
+  log(`Permanently destroying upto ${limit} documents older than 30 days…`);
 
   const documents = await Document.scope("withUnpublished").findAll({
-    attributes: ["id"],
-    where,
-  });
-  const documentIds = documents.map((d) => d.id);
-
-  await Attachment.destroy({
+    attributes: ["id", "teamId", "text"],
     where: {
-      documentId: documentIds,
+      deletedAt: {
+        [Op.lt]: subDays(new Date(), 30),
+      },
     },
+    paranoid: false,
+    limit,
   });
 
+  const query = `
+  SELECT COUNT(id)
+  FROM documents
+  WHERE "searchVector" @@ to_tsquery('english', :query) AND
+  "teamId" = :teamId AND
+  "id" != :documentId
+`;
+
+  for (const document of documents) {
+    const attachmentIds = parseAttachmentIds(document.text);
+
+    for (const attachmentId of attachmentIds) {
+      const [{ count }] = await sequelize.query(query, {
+        type: sequelize.QueryTypes.SELECT,
+        replacements: {
+          documentId: document.id,
+          teamId: document.teamId,
+          query: attachmentId,
+        },
+      });
+
+      if (parseInt(count) === 0) {
+        const attachment = await Attachment.findOne({
+          where: {
+            teamId: document.teamId,
+            id: attachmentId,
+          },
+        });
+
+        if (attachment) {
+          await attachment.destroy();
+
+          log(`Attachment ${attachmentId} deleted`);
+        } else {
+          log(`Unknown attachment ${attachmentId} ignored`);
+        }
+      }
+    }
+  }
+
   await Document.scope("withUnpublished").destroy({
-    where,
+    where: {
+      id: documents.map((document) => document.id),
+    },
     force: true,
   });
 
-  log(`Deleted ${documentIds.length} documents`);
+  log(`Destroyed ${documents.length} documents`);
 
   ctx.body = {
     success: true,

server/api/utils.test.js

@@ -2,69 +2,141 @@
 import subDays from "date-fns/sub_days";
 import TestServer from "fetch-test-server";
 import app from "../app";
-import { Document } from "../models";
-import { sequelize } from "../sequelize";
-import { buildDocument } from "../test/factories";
+import { Attachment, Document } from "../models";
+import { buildAttachment, buildDocument } from "../test/factories";
 import { flushdb } from "../test/support";
 
 const server = new TestServer(app.callback());
 
+jest.mock("aws-sdk", () => {
+  const mS3 = { deleteObject: jest.fn().mockReturnThis(), promise: jest.fn() };
+  return {
+    S3: jest.fn(() => mS3),
+    Endpoint: jest.fn(),
+  };
+});
+
 beforeEach(() => flushdb());
 afterAll(() => server.close());
 
 describe("#utils.gc", () => {
   it("should destroy documents deleted more than 30 days ago", async () => {
-    const document = await buildDocument({
+    await buildDocument({
       publishedAt: new Date(),
+      deletedAt: subDays(new Date(), 60),
     });
 
-    await sequelize.query(
-      `UPDATE documents SET "deletedAt" = '${subDays(
-        new Date(),
-        60
-      ).toISOString()}' WHERE id = '${document.id}'`
-    );
-
     const res = await server.post("/api/utils.gc", {
       body: {
         token: process.env.UTILS_SECRET,
       },
     });
-    const reloaded = await Document.scope().findOne({
-      where: {
-        id: document.id,
-      },
-      paranoid: false,
-    });
+
     expect(res.status).toEqual(200);
-    expect(reloaded).toBe(null);
+    expect(await Document.scope().count()).toEqual(0);
+  });
+
+  it("should destroy attachments no longer referenced", async () => {
+    const document = await buildDocument({
+      publishedAt: subDays(new Date(), 90),
+      deletedAt: subDays(new Date(), 60),
+    });
+
+    const attachment = await buildAttachment({
+      teamId: document.teamId,
+      documentId: document.id,
+    });
+
+    document.text = `![text](${attachment.redirectUrl})`;
+    await document.save();
+
+    const res = await server.post("/api/utils.gc", {
+      body: {
+        token: process.env.UTILS_SECRET,
+      },
+    });
+
+    expect(res.status).toEqual(200);
+    expect(await Attachment.count()).toEqual(0);
+    expect(await Document.scope().count()).toEqual(0);
+  });
+
+  it("should handle unknown attachment ids", async () => {
+    const document = await buildDocument({
+      publishedAt: subDays(new Date(), 90),
+      deletedAt: subDays(new Date(), 60),
+    });
+
+    const attachment = await buildAttachment({
+      teamId: document.teamId,
+      documentId: document.id,
+    });
+
+    document.text = `![text](${attachment.redirectUrl})`;
+    await document.save();
+
+    // remove attachment so it no longer exists in the database, this is also
+    // representative of a corrupt attachment id in the doc or the regex returning
+    // an incorrect string
+    await attachment.destroy({ force: true });
+
+    const res = await server.post("/api/utils.gc", {
+      body: {
+        token: process.env.UTILS_SECRET,
+      },
+    });
+
+    expect(res.status).toEqual(200);
+    expect(await Attachment.count()).toEqual(0);
+    expect(await Document.scope().count()).toEqual(0);
+  });
+
+  it("should not destroy attachments referenced in other documents", async () => {
+    const document1 = await buildDocument();
+
+    const document = await buildDocument({
+      teamId: document1.teamId,
+      publishedAt: subDays(new Date(), 90),
+      deletedAt: subDays(new Date(), 60),
+    });
+
+    const attachment = await buildAttachment({
+      teamId: document1.teamId,
+      documentId: document.id,
+    });
+
+    document1.text = `![text](${attachment.redirectUrl})`;
+    await document1.save();
+
+    document.text = `![text](${attachment.redirectUrl})`;
+    await document.save();
+
+    expect(await Attachment.count()).toEqual(1);
+
+    const res = await server.post("/api/utils.gc", {
+      body: {
+        token: process.env.UTILS_SECRET,
+      },
+    });
+
+    expect(res.status).toEqual(200);
+    expect(await Attachment.count()).toEqual(1);
+    expect(await Document.scope().count()).toEqual(1);
   });
 
   it("should destroy draft documents deleted more than 30 days ago", async () => {
-    const document = await buildDocument({
+    await buildDocument({
       publishedAt: undefined,
+      deletedAt: subDays(new Date(), 60),
     });
 
-    await sequelize.query(
-      `UPDATE documents SET "deletedAt" = '${subDays(
-        new Date(),
-        60
-      ).toISOString()}' WHERE id = '${document.id}'`
-    );
-
     const res = await server.post("/api/utils.gc", {
       body: {
         token: process.env.UTILS_SECRET,
       },
     });
-    const reloaded = await Document.scope().findOne({
-      where: {
-        id: document.id,
-      },
-      paranoid: false,
-    });
     expect(res.status).toEqual(200);
-    expect(reloaded).toBe(null);
+    expect(await Document.scope().count()).toEqual(0);
   });
 
   it("should require authentication", async () => {

server/migrations/20201211080408-attachment-no-cascade.js

@@ -0,0 +1,37 @@
+const tableName = 'attachments';
+
+// because of this issue in Sequelize the foreign key constraint may be named differently depending
+// on when the previous migrations were ran https://github.com/sequelize/sequelize/pull/9890
+const constraintNames = ['attachments_documentId_fkey', 'attachments_foreign_idx'];
+
+module.exports = {
+  up: async (queryInterface, Sequelize) => {
+    let error;
+    for (const constraintName of constraintNames) {
+      try {
+        await queryInterface.sequelize.query(`alter table "${tableName}" drop constraint "${constraintName}"`)
+        return;
+      } catch (err) {
+        error = err;
+      }
+    }
+    throw error;
+  },
+
+  down: async (queryInterface, Sequelize) => {
+    let error;
+    for (const constraintName of constraintNames) {
+      try {
+        await queryInterface.sequelize.query(
+          `alter table "${tableName}"
+            add constraint "${constraintName}" foreign key("documentId") references "documents" ("id")
+            on delete cascade`
+        );
+        return;
+      } catch (err) {
+        error = err;
+      }
+    }
+    throw error;
+  },
+};

server/presenters/document.js

@@ -1,6 +1,7 @@
 // @flow
 import { takeRight } from "lodash";
 import { Attachment, Document, User } from "../models";
+import parseAttachmentIds from "../utils/parseAttachmentIds";
 import { getSignedImageUrl } from "../utils/s3";
 import presentUser from "./user";
 
@@ -8,13 +9,9 @@ type Options = {
   isPublic?: boolean,
 };
 
-const attachmentRegex = /!\[.*?\]\(\/api\/attachments\.redirect\?id=(?<id>[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\)/gi;
-
 // replaces attachments.redirect urls with signed/authenticated url equivalents
-async function replaceImageAttachments(text) {
-  const attachmentIds = [...text.matchAll(attachmentRegex)].map(
-    (match) => match.groups && match.groups.id
-  );
+async function replaceImageAttachments(text: string) {
+  const attachmentIds = parseAttachmentIds(text);
 
   for (const id of attachmentIds) {
     const attachment = await Attachment.findByPk(id);

server/utils/parseAttachmentIds.js

@@ -0,0 +1,8 @@
+// @flow
+const attachmentRegex = /!\[.*?\]\(\/api\/attachments\.redirect\?id=(?<id>[0-9a-f]{8}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{4}-[0-9a-f]{12})\)/gi;
+
+export default function parseAttachmentIds(text: any): string[] {
+  return [...text.matchAll(attachmentRegex)].map(
+    (match) => match.groups && match.groups.id
+  );
+}