fix (backend): prevent chat messages from being deleted when attached file is deleted

docs/downgrade.sql

@@ -1,6 +1,7 @@
 BEGIN;
 
 DELETE FROM "migrations" WHERE name IN (
+    'FixChatFileConstraint1712855579316',
     'DropTimeZone1712425488543',
     'ExpandNoteEdit1711936358554',
     'markLocalFilesNsfwByDefault1709305200000',
@@ -21,6 +22,10 @@ DELETE FROM "migrations" WHERE name IN (
     'RemoveNativeUtilsMigration1705877093218'
 );
 
+-- fix-chat-file-constraint
+ALTER TABLE "messaging_message" DROP CONSTRAINT "FK_535def119223ac05ad3fa9ef64b";
+ALTER TABLE "messaging_message" ADD CONSTRAINT "FK_535def119223ac05ad3fa9ef64b" FOREIGN KEY ("fileId") REFERENCES "drive_file"("id") ON DELETE CASCADE ON UPDATE NO ACTION;
+
 -- drop-time-zone
 ALTER TABLE "abuse_user_report" ALTER "createdAt" TYPE timestamp with time zone;
 ALTER TABLE "access_token" ALTER "createdAt" TYPE timestamp with time zone;

packages/backend-rs/src/model/entity/messaging_message.rs

@@ -35,7 +35,7 @@ pub enum Relation {
         from = "Column::FileId",
         to = "super::drive_file::Column::Id",
         on_update = "NoAction",
-        on_delete = "Cascade"
+        on_delete = "SetNull"
     )]
     DriveFile,
     #[sea_orm(

packages/backend/src/migration/1712855579316-fix-chat-file-constraint.ts

@@ -0,0 +1,21 @@
+import type { MigrationInterface, QueryRunner } from "typeorm";
+
+export class FixChatFileConstraint1712855579316 implements MigrationInterface {
+	public async up(queryRunner: QueryRunner): Promise<void> {
+		await queryRunner.query(
+			`ALTER TABLE "messaging_message" DROP CONSTRAINT "FK_535def119223ac05ad3fa9ef64b"`,
+		);
+		await queryRunner.query(
+			`ALTER TABLE "messaging_message" ADD CONSTRAINT "FK_535def119223ac05ad3fa9ef64b" FOREIGN KEY ("fileId") REFERENCES "drive_file"("id") ON DELETE SET NULL ON UPDATE NO ACTION`,
+		);
+	}
+
+	public async down(queryRunner: QueryRunner): Promise<void> {
+		await queryRunner.query(
+			`ALTER TABLE "messaging_message" DROP CONSTRAINT "FK_535def119223ac05ad3fa9ef64b"`,
+		);
+		await queryRunner.query(
+			`ALTER TABLE "messaging_message" ADD CONSTRAINT "FK_535def119223ac05ad3fa9ef64b" FOREIGN KEY ("fileId") REFERENCES "drive_file"("id") ON DELETE CASCADE ON UPDATE NO ACTION`,
+		);
+	}
+}

packages/backend/src/models/entities/messaging-message.ts

@@ -97,7 +97,7 @@ export class MessagingMessage {
 	public group: Relation<UserGroup | null>;
 
 	@ManyToOne(() => DriveFile, {
-		onDelete: "CASCADE", // TODO: change this to SET NULL
+		onDelete: "SET NULL",
 		nullable: true,
 	})
 	@JoinColumn()