[CORL-8] prevent repeat comments (#2632)

* prevent users from reposting the same comment

* fix tests

* fix lints

* update comments for users service

* make updates based on review

src/core/client/admin/components/ModerateCard/MarkersContainer.spec.tsx

@@ -28,6 +28,7 @@ it("renders all markers", () => {
               COMMENT_DETECTED_SUSPECT_WORD: 1,
               COMMENT_REPORTED_OFFENSIVE: 2,
               COMMENT_REPORTED_SPAM: 3,
+              COMMENT_DETECTED_REPEAT_POST: 1,
             },
           },
         },
@@ -71,6 +72,7 @@ it("renders some markers", () => {
               COMMENT_DETECTED_SUSPECT_WORD: 0,
               COMMENT_REPORTED_OFFENSIVE: 2,
               COMMENT_REPORTED_SPAM: 0,
+              COMMENT_DETECTED_REPEAT_POST: 0,
             },
           },
         },

src/core/client/admin/components/ModerateCard/MarkersContainer.tsx

@@ -32,7 +32,7 @@ const markers: Array<
   c =>
     (c.status === "PREMOD" && (
       <Localized id="moderate-marker-preMod" key={keyCounter++}>
-        <Marker color="primary">Pre-Mod</Marker>
+        <Marker color="primary">Pre-mod</Marker>
       </Localized>
     )) ||
     null,
@@ -48,7 +48,7 @@ const markers: Array<
     (c.revision &&
       c.revision.actionCounts.flag.reasons.COMMENT_DETECTED_BANNED_WORD && (
         <Localized id="moderate-marker-bannedWord" key={keyCounter++}>
-          <Marker color="error">Banned Word</Marker>
+          <Marker color="error">Banned word</Marker>
         </Localized>
       )) ||
     null,
@@ -57,7 +57,7 @@ const markers: Array<
       c.revision.actionCounts.flag.reasons.COMMENT_DETECTED_SUSPECT_WORD && (
         <Localized id="moderate-marker-suspectWord" key={keyCounter++}>
           <Marker color="error" variant="filled">
-            Suspect Word
+            Suspect word
           </Marker>
         </Localized>
       )) ||
@@ -66,7 +66,7 @@ const markers: Array<
     (c.revision &&
       c.revision.actionCounts.flag.reasons.COMMENT_DETECTED_SPAM && (
         <Localized id="moderate-marker-spamDetected" key={keyCounter++}>
-          <Marker color="error">Spam Detected</Marker>
+          <Marker color="error">Spam detected</Marker>
         </Localized>
       )) ||
     null,
@@ -78,11 +78,19 @@ const markers: Array<
         </Localized>
       )) ||
     null,
+  c =>
+    (c.revision &&
+      c.revision.actionCounts.flag.reasons.COMMENT_DETECTED_REPEAT_POST && (
+        <Localized id="moderate-marker-repeatPost" key={keyCounter++}>
+          <Marker color="error">Repeat comment</Marker>
+        </Localized>
+      )) ||
+    null,
   c =>
     (c.revision &&
       c.revision.actionCounts.flag.reasons.COMMENT_DETECTED_RECENT_HISTORY && (
         <Localized id="moderate-marker-recentHistory" key={keyCounter++}>
-          <Marker color="error">Recent History</Marker>
+          <Marker color="error">Recent history</Marker>
         </Localized>
       )) ||
     null,
@@ -162,6 +170,7 @@ const enhanced = withFragmentContainer<MarkersContainerProps>({
               COMMENT_DETECTED_SUSPECT_WORD
               COMMENT_REPORTED_OFFENSIVE
               COMMENT_REPORTED_SPAM
+              COMMENT_DETECTED_REPEAT_POST
             }
           }
         }

src/core/client/admin/components/ModerateCard/__snapshots__/MarkersContainer.spec.tsx.snap

@@ -16,6 +16,7 @@ exports[`renders all markers 1`] = `
                   "COMMENT_DETECTED_BANNED_WORD": 1,
                   "COMMENT_DETECTED_LINKS": 1,
                   "COMMENT_DETECTED_RECENT_HISTORY": 1,
+                  "COMMENT_DETECTED_REPEAT_POST": 1,
                   "COMMENT_DETECTED_SPAM": 1,
                   "COMMENT_DETECTED_SUSPECT_WORD": 1,
                   "COMMENT_DETECTED_TOXIC": 1,
@@ -54,7 +55,7 @@ exports[`renders all markers 1`] = `
     <withPropsOnChange(Marker)
       color="primary"
     >
-      Pre-Mod
+      Pre-mod
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -72,7 +73,7 @@ exports[`renders all markers 1`] = `
     <withPropsOnChange(Marker)
       color="error"
     >
-      Banned Word
+      Banned word
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -82,7 +83,7 @@ exports[`renders all markers 1`] = `
       color="error"
       variant="filled"
     >
-      Suspect Word
+      Suspect word
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -91,7 +92,7 @@ exports[`renders all markers 1`] = `
     <withPropsOnChange(Marker)
       color="error"
     >
-      Spam Detected
+      Spam detected
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -103,13 +104,22 @@ exports[`renders all markers 1`] = `
       Toxic
     </withPropsOnChange(Marker)>
   </Localized>
+  <Localized
+    id="moderate-marker-repeatPost"
+  >
+    <withPropsOnChange(Marker)
+      color="error"
+    >
+      Repeat comment
+    </withPropsOnChange(Marker)>
+  </Localized>
   <Localized
     id="moderate-marker-recentHistory"
   >
     <withPropsOnChange(Marker)
       color="error"
     >
-      Recent History
+      Recent history
     </withPropsOnChange(Marker)>
   </Localized>
   <withPropsOnChange(Marker)
@@ -161,6 +171,7 @@ exports[`renders some markers 1`] = `
                   "COMMENT_DETECTED_BANNED_WORD": 1,
                   "COMMENT_DETECTED_LINKS": 0,
                   "COMMENT_DETECTED_RECENT_HISTORY": 1,
+                  "COMMENT_DETECTED_REPEAT_POST": 0,
                   "COMMENT_DETECTED_SPAM": 0,
                   "COMMENT_DETECTED_SUSPECT_WORD": 0,
                   "COMMENT_DETECTED_TOXIC": 1,
@@ -199,7 +210,7 @@ exports[`renders some markers 1`] = `
     <withPropsOnChange(Marker)
       color="primary"
     >
-      Pre-Mod
+      Pre-mod
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -208,7 +219,7 @@ exports[`renders some markers 1`] = `
     <withPropsOnChange(Marker)
       color="error"
     >
-      Banned Word
+      Banned word
     </withPropsOnChange(Marker)>
   </Localized>
   <Localized
@@ -226,7 +237,7 @@ exports[`renders some markers 1`] = `
     <withPropsOnChange(Marker)
       color="error"
     >
-      Recent History
+      Recent history
     </withPropsOnChange(Marker)>
   </Localized>
   <withPropsOnChange(Marker)

src/core/client/admin/test/fixtures.ts

@@ -526,6 +526,7 @@ export const baseComment = createFixture<GQLComment>({
           COMMENT_DETECTED_SUSPECT_WORD: 0,
           COMMENT_REPORTED_OFFENSIVE: 0,
           COMMENT_REPORTED_SPAM: 0,
+          COMMENT_DETECTED_REPEAT_POST: 0,
         },
       },
     },

src/core/client/admin/test/moderate/__snapshots__/regularQueue.spec.tsx.snap

@@ -1550,7 +1550,7 @@ exports[`renders reported queue with comments and load more 1`] = `
               <span
                 className="Marker-root Marker-colorPrimary Marker-variantRegular"
               >
-                Pre-Mod
+                Pre-mod
               </span>
               <span
                 className="Marker-root Marker-colorError Marker-variantRegular"

src/core/client/test/helpers/fixture.ts

@@ -100,6 +100,7 @@ export function createComment(author?: GQLUser) {
             COMMENT_DETECTED_SUSPECT_WORD: 0,
             COMMENT_REPORTED_OFFENSIVE: 0,
             COMMENT_REPORTED_SPAM: 0,
+            COMMENT_DETECTED_REPEAT_POST: 0,
           },
         },
       },
@@ -147,6 +148,7 @@ export function createComment(author?: GQLUser) {
           COMMENT_DETECTED_BANNED_WORD: 0,
           COMMENT_DETECTED_SUSPECT_WORD: 0,
           COMMENT_DETECTED_PREMOD_USER: 0,
+          COMMENT_DETECTED_REPEAT_POST: 0,
         },
       },
     },

src/core/common/constants.ts

@@ -63,3 +63,9 @@ export const COMMENT_LIMIT_WINDOW_SECONDS = 3;
  * DEFAULT_SESSION_LENTTH is the length of time in seconds a session is valid for unless configured in tenant.
  */
 export const DEFAULT_SESSION_LENGTH = 7776000;
+
+/**
+ * COMMENT_REPEAT_POST_TIMESPAN is the length of time in seconds that a previous comment ID is stored for a
+ * user to prevent them from posting the same comment repeatedly.
+ */
+export const COMMENT_REPEAT_POST_TIMESPAN = 21600;

src/core/common/errors.ts

@@ -316,4 +316,10 @@ export enum ERROR_CODES {
   RAW_QUERY_NOT_AUTHORIZED = "RAW_QUERY_NOT_AUTHORIZED",
 
   USER_ALREADY_PREMOD = "USER_ALREADY_PREMOD",
+
+  /**
+   * REPEAT_POST is returned if a user attempts to post the same comment more than once
+   * in a row within a given time frame
+   */
+  REPEAT_POST = "REPEAT_POST",
 }

src/core/server/errors/index.ts

@@ -580,6 +580,16 @@ export class SpamCommentError extends CoralError {
   }
 }
 
+export class RepeatPostCommentError extends CoralError {
+  constructor() {
+    super({
+      code: ERROR_CODES.REPEAT_POST,
+      type: ERROR_TYPES.MODERATION_NUDGE_ERROR,
+      status: 400,
+    });
+  }
+}
+
 export class UserAlreadySuspendedError extends CoralError {
   constructor(until: Date) {
     super({

src/core/server/errors/translations.ts

@@ -55,4 +55,5 @@ export const ERROR_TRANSLATIONS: Record<ERROR_CODES, string> = {
   PERSISTED_QUERY_NOT_FOUND: "error-persistedQueryNotFound",
   RAW_QUERY_NOT_AUTHORIZED: "error-rawQueryNotAuthorized",
   USER_ALREADY_PREMOD: "error-userAlreadyPremod",
+  REPEAT_POST: "error-repeatPost",
 };

src/core/server/graph/tenant/schema/schema.graphql

@@ -146,6 +146,11 @@ enum COMMENT_FLAG_DETECTED_REASON {
   COMMENT_DETECTED_PREMOD_USER is used when a Comment author has been tagged as requiring premoderation
   """
   COMMENT_DETECTED_PREMOD_USER
+
+  """
+  COMMENT_DETECTED_REPEAT_POST is used when a Comment's text exactly matches a previous recent comment from the same author
+  """
+  COMMENT_DETECTED_REPEAT_POST
 }
 
 """
@@ -163,6 +168,7 @@ enum COMMENT_FLAG_REASON {
   COMMENT_DETECTED_SUSPECT_WORD
   COMMENT_DETECTED_RECENT_HISTORY
   COMMENT_DETECTED_PREMOD_USER
+  COMMENT_DETECTED_REPEAT_POST
 }
 
 """
@@ -198,6 +204,7 @@ type FlagReasonActionCounts {
   COMMENT_DETECTED_SUSPECT_WORD: Int!
   COMMENT_DETECTED_RECENT_HISTORY: Int!
   COMMENT_DETECTED_PREMOD_USER: Int!
+  COMMENT_DETECTED_REPEAT_POST: Int!
 }
 
 type Flag {

src/core/server/locales/en-US/errors.ftl

@@ -57,3 +57,4 @@ error-passwordIncorrect = Incorrect password. Please try again.
 error-usernameAlreadyUpdated = You may only change your username once every { framework-timeago-time }.
 error-persistedQueryNotFound = The persisted query with ID { $id } was not found.
 error-rawQueryNotAuthorized = You are not authorized to execute this query.
+error-repeatPost = Are you sure? This comment is very similar to your previous comment.

src/core/server/models/action/__snapshots__/comment.spec.ts.snap

@@ -21,6 +21,7 @@ Object {
       "COMMENT_DETECTED_LINKS": 0,
       "COMMENT_DETECTED_PREMOD_USER": 0,
       "COMMENT_DETECTED_RECENT_HISTORY": 0,
+      "COMMENT_DETECTED_REPEAT_POST": 0,
       "COMMENT_DETECTED_SPAM": 0,
       "COMMENT_DETECTED_SUSPECT_WORD": 0,
       "COMMENT_DETECTED_TOXIC": 0,

src/core/server/services/comments/comments.ts

@@ -49,7 +49,10 @@ import {
 import { AugmentedRedis } from "coral-server/services/redis";
 import { Request } from "coral-server/types/express";
 
-import { updateUserLastWroteCommentTimestamp } from "../users";
+import {
+  updateUserLastCommentID,
+  updateUserLastWroteCommentTimestamp,
+} from "../users";
 import { addCommentActions, CreateAction } from "./actions";
 import { calculateCounts, calculateCountsDiff } from "./moderation/counts";
 import { PhaseResult, processForModeration } from "./pipeline";
@@ -186,6 +189,8 @@ export async function create(
     now
   );
 
+  await updateUserLastCommentID(redis, tenant, author, comment.id);
+
   // Pull the revision out.
   const revision = getLatestRevision(comment);
 

src/core/server/services/comments/pipeline/phases/index.ts

@@ -8,6 +8,7 @@ import { preModerate } from "./preModerate";
 import { premodUser } from "./preModerateUser";
 import { purify } from "./purify";
 import { recentCommentHistory } from "./recentCommentHistory";
+import { repeatPost } from "./repeatPost";
 import { spam } from "./spam";
 import { staff } from "./staff";
 import { storyClosed } from "./storyClosed";
@@ -25,6 +26,7 @@ export const moderationPhases: IntermediateModerationPhase[] = [
   commentingDisabled,
   linkify,
   purify,
+  repeatPost,
   wordList,
   staff,
   toxic,

src/core/server/services/comments/pipeline/phases/repeatPost.ts

@@ -0,0 +1,86 @@
+import { RepeatPostCommentError } from "coral-server/errors";
+import {
+  GQLCOMMENT_FLAG_REASON,
+  GQLCOMMENT_STATUS,
+} from "coral-server/graph/tenant/schema/__generated__/types";
+import logger from "coral-server/logger";
+import { ACTION_TYPE } from "coral-server/models/action/comment";
+import { getLatestRevision } from "coral-server/models/comment/helpers";
+import {
+  IntermediateModerationPhase,
+  IntermediatePhaseResult,
+} from "coral-server/services/comments/pipeline";
+import { retrieveUserLastComment } from "coral-server/services/users";
+
+export const repeatPost: IntermediateModerationPhase = async ({
+  story,
+  mongo,
+  tenant,
+  comment,
+  author,
+  req,
+  nudge,
+  redis,
+}): Promise<IntermediatePhaseResult | void> => {
+  const log = logger.child(
+    {
+      tenantID: tenant.id,
+    },
+    true
+  );
+
+  if (!comment.body) {
+    return;
+  }
+
+  try {
+    log.trace("checking comment for repeat content");
+
+    const lastComment = await retrieveUserLastComment(
+      mongo,
+      redis,
+      tenant,
+      author
+    );
+
+    if (!lastComment) {
+      return;
+    }
+
+    const revision = getLatestRevision(lastComment);
+    const isRepeatComment = revision.body === comment.body;
+
+    if (isRepeatComment) {
+      log.trace({ isRepeatComment }, "comment contains repeat content");
+
+      // Throw an error if we're nudging instead of recording.
+      if (nudge) {
+        throw new RepeatPostCommentError();
+      }
+
+      return {
+        status: GQLCOMMENT_STATUS.SYSTEM_WITHHELD,
+        actions: [
+          {
+            userID: null,
+            actionType: ACTION_TYPE.FLAG,
+            reason: GQLCOMMENT_FLAG_REASON.COMMENT_DETECTED_REPEAT_POST,
+          },
+        ],
+        metadata: {},
+      };
+    }
+
+    log.trace({ isRepeatComment }, "comment is not repeated");
+  } catch (err) {
+    // Rethrow any RepeatPostError.
+    if (err instanceof RepeatPostCommentError) {
+      throw err;
+    }
+
+    log.error(
+      { err },
+      "could not determine if comment contained duplicate content"
+    );
+  }
+};

src/core/server/services/users/users.ts

@@ -4,6 +4,7 @@ import { Db } from "mongodb";
 import {
   ALLOWED_USERNAME_CHANGE_FREQUENCY,
   COMMENT_LIMIT_WINDOW_SECONDS,
+  COMMENT_REPEAT_POST_TIMESPAN,
   DOWNLOAD_LIMIT_TIMEFRAME,
 } from "coral-common/constants";
 import { SCHEDULED_DELETION_TIMESPAN_DAYS } from "coral-common/constants";
@@ -31,6 +32,7 @@ import {
   GQLUSER_ROLE,
 } from "coral-server/graph/tenant/schema/__generated__/types";
 import logger from "coral-server/logger";
+import { Comment, retrieveComment } from "coral-server/models/comment";
 import { Tenant } from "coral-server/models/tenant";
 import {
   banUser,
@@ -1190,6 +1192,13 @@ function userLastWroteCommentTimestampKey(
   return `${tenant.id}:lastCommentTimestamp:${user.id}`;
 }
 
+function userLastCommentIDKey(
+  tenant: Pick<Tenant, "id">,
+  user: Pick<User, "id">
+) {
+  return `${tenant.id}:lastCommentID:${user.id}`;
+}
+
 /**
  * retrieveUserLastWroteCommentTimestamp will return the timestamp (if set) that
  * the user last wrote a comment on. This will return null if the comment was
@@ -1245,3 +1254,46 @@ export async function updateUserLastWroteCommentTimestamp(
     throw new RateLimitExceeded("createComment", 1);
   }
 }
+
+/**
+ * updateUserLastCommentID will update the id of the users most recent comment.
+ *
+ * @param redis the Redis instance that Coral interacts with
+ * @param tenant the Tenant to operate on
+ * @param user the User that we're setting the limit for
+ * @param commentID the id of the comment
+ */
+export async function updateUserLastCommentID(
+  redis: AugmentedRedis,
+  tenant: Tenant,
+  user: User,
+  commentID: string
+) {
+  const key = userLastCommentIDKey(tenant, user);
+
+  await redis.set(key, commentID, "EX", COMMENT_REPEAT_POST_TIMESPAN);
+}
+
+/**
+ * retrieveUserLastComment will return the id (if set) of the comment that
+ * the user last wrote. This will return null if the user has not made a comment
+ * within the CURRENT_REPEAT_POST_TIMESPAN.
+ *
+ * @param mongo the db
+ * @param redis the Redis instance that Coral interacts with
+ * @param tenant the Tenant to operate on
+ * @param user the User that we're looking up the limit for
+ */
+export async function retrieveUserLastComment(
+  mongo: Db,
+  redis: AugmentedRedis,
+  tenant: Tenant,
+  user: User
+): Promise<Readonly<Comment> | null> {
+  const id: string | null = await redis.get(userLastCommentIDKey(tenant, user));
+  if (!id) {
+    return null;
+  }
+
+  return retrieveComment(mongo, tenant.id, id);
+}

src/locales/en-US/admin.ftl

@@ -387,16 +387,17 @@ moderate-navigation-pending = Pending
 moderate-navigation-unmoderated = unmoderated
 moderate-navigation-rejected = rejected
 
-moderate-marker-preMod = Pre-Mod
+moderate-marker-preMod = Pre-mod
 moderate-marker-link = Link
-moderate-marker-bannedWord = Banned Word
-moderate-marker-suspectWord = Suspect Word
+moderate-marker-bannedWord = Banned word
+moderate-marker-suspectWord = Suspect word
 moderate-marker-spam = Spam
-moderate-marker-spamDetected = Spam Detected
+moderate-marker-spamDetected = Spam detected
 moderate-marker-toxic = Toxic
-moderate-marker-recentHistory = Recent History
-moderate-marker-bodyCount = Body Count
+moderate-marker-recentHistory = Recent history
+moderate-marker-bodyCount = Body count
 moderate-marker-offensive = Offensive
+moderate-marker-repeatPost = Repeat comment
 
 moderate-markers-details = Details
 moderate-flagDetails-offensive = Offensive