feat(revision): include author details in metadata dto

Signed-off-by: David Mehren <git@herrmehren.de>

src/revisions/revision-metadata.dto.ts

@@ -5,7 +5,7 @@
  */
 import { ApiProperty } from '@nestjs/swagger';
 import { Type } from 'class-transformer';
-import { IsDate, IsNumber } from 'class-validator';
+import { IsDate, IsNumber, IsString } from 'class-validator';
 
 import { Revision } from './revision.entity';
 
@@ -34,4 +34,19 @@ export class RevisionMetadataDto {
   @IsNumber()
   @ApiProperty()
   length: number;
+
+  /**
+   * List of the usernames that have contributed to this revision
+   * Does not include anonymous users
+   */
+  @IsString()
+  @ApiProperty()
+  authorUsernames: string[];
+
+  /**
+   * Count of anonymous users that have contributed to this revision
+   */
+  @IsNumber()
+  @ApiProperty()
+  anonymousAuthorCount: number;
 }

src/revisions/revisions.service.ts

@@ -16,6 +16,11 @@ import { RevisionMetadataDto } from './revision-metadata.dto';
 import { RevisionDto } from './revision.dto';
 import { Revision } from './revision.entity';
 
+class RevisionUserInfo {
+  usernames: string[];
+  anonymousUserCount: number;
+}
+
 @Injectable()
 export class RevisionsService {
   constructor(
@@ -103,20 +108,42 @@ export class RevisionsService {
     return revision;
   }
 
-  toRevisionMetadataDto(revision: Revision): RevisionMetadataDto {
+  async getRevisionUserInfo(revision: Revision): Promise<RevisionUserInfo> {
+    const users = await Promise.all(
+      (
+        await revision.edits
+      ).map(async (edit) => await (await edit.author).user),
+    );
+    const usernames = users.flatMap((user) => (user ? [user.username] : []));
+    const anonymousUserCount = users.filter((user) => user === null).length;
+    return {
+      usernames: usernames,
+      anonymousUserCount: anonymousUserCount,
+    };
+  }
+
+  async toRevisionMetadataDto(
+    revision: Revision,
+  ): Promise<RevisionMetadataDto> {
+    const revisionUserInfo = await this.getRevisionUserInfo(revision);
     return {
       id: revision.id,
       length: revision.length,
       createdAt: revision.createdAt,
+      authorUsernames: revisionUserInfo.usernames,
+      anonymousAuthorCount: revisionUserInfo.anonymousUserCount,
     };
   }
 
   async toRevisionDto(revision: Revision): Promise<RevisionDto> {
+    const revisionUserInfo = await this.getRevisionUserInfo(revision);
     return {
       id: revision.id,
       content: revision.content,
       length: revision.length,
       createdAt: revision.createdAt,
+      authorUsernames: revisionUserInfo.usernames,
+      anonymousAuthorCount: revisionUserInfo.anonymousUserCount,
       patch: revision.patch,
       edits: await Promise.all(
         (