[CORL-1180] Moderation + Editing Improvements (#3020)

* fix: handle moderating edited comments better

* fix: add back deleted audit trail entry

Co-authored-by: kodiakhq[bot] <49736102+kodiakhq[bot]@users.noreply.github.com>

src/core/server/models/comment/helpers.ts

@@ -47,6 +47,13 @@ export function getLatestRevision(
   return comment.revisions[comment.revisions.length - 1];
 }
 
+export function hasRevision(
+  comment: Pick<Comment, "revisions">,
+  revisionID: string
+): boolean {
+  return comment.revisions.some((revision) => revision.id === revisionID);
+}
+
 export function calculateRejectionRate(counts: CommentStatusCounts): number {
   const published = calculateTotalPublishedCommentCount(counts);
   const rejected = counts[GQLCOMMENT_STATUS.REJECTED];

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

@@ -5,7 +5,12 @@ import {
   createCommentModerationAction,
   CreateCommentModerationActionInput,
 } from "coral-server/models/action/moderation/comment";
-import { updateCommentStatus } from "coral-server/models/comment";
+import {
+  getLatestRevision,
+  hasRevision,
+  retrieveComment,
+  updateCommentStatus,
+} from "coral-server/models/comment";
 import { Tenant } from "coral-server/models/tenant";
 
 export type Moderate = CreateCommentModerationActionInput;
@@ -18,18 +23,32 @@ export default async function moderate(
 ) {
   // TODO: wrap these operations in a transaction?
 
-  // Create the moderation action in the audit log.
-  const action = await createCommentModerationAction(
-    mongo,
-    tenant.id,
-    input,
-    now
-  );
-  if (!action) {
-    // TODO: wrap in better error?
-    throw new Error("could not create moderation action");
+  // Get the comment that we're moderating.
+  const comment = await retrieveComment(mongo, tenant.id, input.commentID);
+  if (!comment) {
+    throw new CommentNotFoundError(input.commentID, input.commentRevisionID);
   }
 
+  // Get the latest revision on that comment.
+  const revision = getLatestRevision(comment);
+
+  // Ensure that the latest revision is the same revision that we're moderating.
+  if (revision.id !== input.commentRevisionID) {
+    // The revision has been updated since then! Ensure that this revision ID
+    // does exist.
+    if (!hasRevision(comment, input.commentRevisionID)) {
+      throw new CommentNotFoundError(input.commentID, input.commentRevisionID);
+    }
+
+    // The comment has this revision, it just isn't the latest one. Return the
+    // same comment back because we didn't modify anything.
+    return { before: comment, after: null };
+  }
+
+  // TODO: (wyattjoh) this is a pretty race condition prone check here, replace
+  // with a more concrete query that can prevent the comment being edited in the
+  // time it takes to go from the above block to the next block.
+
   // Update the Comment's status.
   const result = await updateCommentStatus(
     mongo,
@@ -42,5 +61,17 @@ export default async function moderate(
     throw new CommentNotFoundError(input.commentID, input.commentRevisionID);
   }
 
+  // Create the moderation action in the audit log.
+  const action = await createCommentModerationAction(
+    mongo,
+    tenant.id,
+    input,
+    now
+  );
+  if (!action) {
+    // TODO: wrap in better error?
+    throw new Error("could not create moderation action");
+  }
+
   return result;
 }

src/core/server/stacks/approveComment.ts

@@ -32,6 +32,11 @@ const approveComment = async (
     now
   );
 
+  // If the comment hasn't been updated, skip the rest of the steps.
+  if (!result.after) {
+    return result.before;
+  }
+
   // Update all the comment counts on stories and users.
   const counts = await updateAllCommentCounts(mongo, redis, {
     ...result,

src/core/server/stacks/rejectComment.ts

@@ -37,6 +37,11 @@ const rejectComment = async (
     now
   );
 
+  // If the comment hasn't been updated, skip the rest of the steps.
+  if (!result.after) {
+    return result.before;
+  }
+
   // Update all the comment counts on stories and users.
   const counts = await updateAllCommentCounts(mongo, redis, {
     ...result,