factor out tuple logic into from-tuple.ts

packages/backend/src/core/activitypub/ApDbResolverService.ts

@@ -59,7 +59,7 @@ export class ApDbResolverService implements OnApplicationShutdown {
 	}
 
 	@bindThis
-	public parseUri(value: string | IObject): UriParseResult {
+	public parseUri(value: string | IObject | [string | IObject]): UriParseResult {
 		const separator = '/';
 
 		const uri = new URL(getApId(value));
@@ -78,7 +78,7 @@ export class ApDbResolverService implements OnApplicationShutdown {
 	 * AP Note => Misskey Note in DB
 	 */
 	@bindThis
-	public async getNoteFromApId(value: string | IObject): Promise<MiNote | null> {
+	public async getNoteFromApId(value: string | IObject | [string | IObject]): Promise<MiNote | null> {
 		const parsed = this.parseUri(value);
 
 		if (parsed.local) {
@@ -99,9 +99,6 @@ export class ApDbResolverService implements OnApplicationShutdown {
 	 */
 	@bindThis
 	public async getUserFromApId(value: string | IObject | [string | IObject]): Promise<MiLocalUser | MiRemoteUser | null> {
-		// eslint-disable-next-line no-param-reassign
-		if (Array.isArray(value)) value = value[0];
-
 		const parsed = this.parseUri(value);
 
 		if (parsed.local) {

packages/backend/src/core/activitypub/ApInboxService.ts

@@ -41,6 +41,7 @@ import { ApPersonService } from './models/ApPersonService.js';
 import { ApQuestionService } from './models/ApQuestionService.js';
 import type { Resolver } from './ApResolverService.js';
 import type { IAccept, IAdd, IAnnounce, IBlock, ICreate, IDelete, IFlag, IFollow, ILike, IObject, IReject, IRemove, IUndo, IUpdate, IMove, IPost } from './type.js';
+import { fromTuple } from '@/misc/from-tuple.js';
 
 @Injectable()
 export class ApInboxService {
@@ -253,7 +254,7 @@ export class ApInboxService {
 		}
 
 		if (activity.target === actor.featured) {
-			const object = Array.isArray(activity.object) ? activity.object[0] : activity.object;
+			const object = fromTuple(activity.object);
 			const note = await this.apNoteService.resolveNote(object);
 			if (note == null) return 'note not found';
 			await this.notePiningService.addPinned(actor, note.id);
@@ -271,7 +272,7 @@ export class ApInboxService {
 
 		const resolver = this.apResolverService.createResolver();
 
-		const activityObject = Array.isArray(activity.object) ? activity.object[0] : activity.object;
+		const activityObject = fromTuple(activity.object);
 		if (!activityObject) return 'skip: activity has no object property';
 		const targetUri = getApId(activityObject);
 		if (targetUri.startsWith('bear:')) return 'skip: bearcaps url not supported.';
@@ -372,7 +373,7 @@ export class ApInboxService {
 
 		this.logger.info(`Create: ${uri}`);
 
-		const activityObject = Array.isArray(activity.object) ? activity.object[0] : activity.object;
+		const activityObject = fromTuple(activity.object);
 		if (!activityObject) return 'skip: activity has no object property';
 		const targetUri = getApId(activityObject);
 		if (targetUri.startsWith('bear:')) return 'skip: bearcaps url not supported.';
@@ -451,7 +452,7 @@ export class ApInboxService {
 		// 削除対象objectのtype
 		let formerType: string | undefined;
 
-		const activityObject = Array.isArray(activity.object) ? activity.object[0] : activity.object;
+		const activityObject = fromTuple(activity.object);
 		if (typeof activityObject === 'string') {
 			// typeが不明だけど、どうせ消えてるのでremote resolveしない
 			formerType = undefined;
@@ -619,7 +620,7 @@ export class ApInboxService {
 		}
 
 		if (activity.target === actor.featured) {
-			const activityObject = Array.isArray(activity.object) ? activity.object[0] : activity.object;
+			const activityObject = fromTuple(activity.object);
 			const note = await this.apNoteService.resolveNote(activityObject);
 			if (note == null) return 'note not found';
 			await this.notePiningService.removePinned(actor, note.id);

packages/backend/src/core/activitypub/ApResolverService.ts

@@ -21,6 +21,7 @@ import { ApDbResolverService } from './ApDbResolverService.js';
 import { ApRendererService } from './ApRendererService.js';
 import { ApRequestService } from './ApRequestService.js';
 import type { IObject, ICollection, IOrderedCollection } from './type.js';
+import { fromTuple } from '@/misc/from-tuple.js';
 
 export class Resolver {
 	private history: Set<string>;
@@ -69,7 +70,7 @@ export class Resolver {
 	@bindThis
 	public async resolve(value: string | IObject | [string | IObject]): Promise<IObject> {
 		// eslint-disable-next-line no-param-reassign
-		if (Array.isArray(value)) value = value[0];
+		value = fromTuple(value);
 
 		if (typeof value !== 'string') {
 			return value;

packages/backend/src/core/activitypub/type.ts

@@ -3,6 +3,8 @@
  * SPDX-License-Identifier: AGPL-3.0-only
  */
 
+import { fromTuple } from '@/misc/from-tuple.js';
+
 export type Obj = { [x: string]: any };
 export type ApObject = IObject | string | (IObject | string)[];
 
@@ -54,7 +56,7 @@ export function getOneApId(value: ApObject): string {
  */
 export function getApId(value: string | IObject | [string | IObject]): string {
 	// eslint-disable-next-line no-param-reassign
-	if (Array.isArray(value)) value = value[0];
+	value = fromTuple(value);
 
 	if (typeof value === 'string') return value;
 	if (typeof value.id === 'string') return value.id;

packages/backend/src/misc/from-tuple.ts

@@ -0,0 +1,7 @@
+export function fromTuple<T>(value: T | [T]): T {
+	if (Array.isArray(value)) {
+		return value[0];
+	}
+
+	return value;
+}

packages/backend/test/unit/misc/from-tuple.ts

@@ -0,0 +1,13 @@
+import { fromTuple } from '@/misc/from-tuple.js';
+
+describe(fromTuple, () => {
+	it('should return value when value is not an array', () => {
+		const value = fromTuple('abc');
+		expect(value).toBe('abc');
+	});
+
+	it('should return first element when value is an array', () => {
+		const value = fromTuple(['abc']);
+		expect(value).toBe('abc');
+	});
+});