Teammates: Run data migration on legacy comment search documents to update date format

[whipermr5]

Related to #7569. Script from #7682 can be run in the near future to update all comment search documents to the latest format (with dates in the currently prescribed format).

[damithc]

Will do in the next release, after we are sure the current release is stable.

[damithc]

I tried running the script. It timed out after a while because the whole thing takes too long.
Then I running it for a part of data only. Found out that out of 7000+ comments, only 3 have wrong date format. All 3 them failed to migrate because of NullPointerException, caused by 'cannot locate feedback response'. Perhaps we just leave those three alone?. Or is there any way to delete them?

[whipermr5]

I'm guessing the NPE occurs inside the .build() step of https://github.com/TEAMMATES/teammates/blob/a446786d53aa235b020d6dfdea1ca64562a595d6/src/client/java/teammates/client/scripts/DataMigrationForFeedbackResponseCommentSearchDocument.java#L124
?

[damithc]

Here's an example:

INFO: Trying to get non-existent response: abczfnRlYW1tYXRlc3Y0ch0LEhBGZWVkYmFja1F1ZXN0aW9uGICAgI7Px54JDA%[email protected]%[email protected].
Exception in thread "main" java.lang.NullPointerException
    at teammates.storage.search.FeedbackResponseCommentSearchDocument.prepareData(FeedbackResponseCommentSearchDocument.java:80)
    at teammates.storage.search.SearchDocument.build(SearchDocument.java:39)
    at teammates.client.scripts.DataMigrationForFeedbackResponseCommentSearchDocument.queueDocumentUpdate(DataMigrationForFeedbackResponseCommentSearchDocument.java:127)
    at teammates.client.scripts.DataMigrationForFeedbackResponseCommentSearchDocument.fixDocuments(DataMigrationForFeedbackResponseCommentSearchDocument.java:115)
    at teammates.client.scripts.DataMigrationForFeedbackResponseCommentSearchDocument.doOperation(DataMigrationForFeedbackResponseCommentSearchDocument.java:45)
    at teammates.client.remoteapi.RemoteApiClient.doOperationRemotely(RemoteApiClient.java:49)
    at teammates.client.scripts.DataMigrationForFeedbackResponseCommentSearchDocumentDateFormat.main(DataMigrationForFeedbackResponseCommentSearchDocumentDateFormat.java:43)

[whipermr5]

Yes; it's possible to delete them. The simplest way would be:

// replace with ID of non-existent response as shown in the log
String invalidResponseId = "abczfnRlYW1tYXRlc3Y0ch0LEhBGZWVkYmFja1F1ZXN0aW9uGICAgI7Px54JDA%[email protected]%[email protected]";

FeedbackResponseCommentsLogic frcLogic = FeedbackResponseCommentsLogic.inst();

List<FeedbackResponseCommentAttributes> invalidComments =
        frcLogic.getFeedbackResponseCommentForResponse(invalidResponseId);
for (FeedbackResponseCommentAttributes invalidComment : invalidComments) {
    frcLogic.deleteDocument(invalidComment);
}
frcLogic.deleteFeedbackResponseCommentsForResponse(invalidResponseId);

[damithc]

Ok, deleted all three invalid responses.