refactor: 可読性のため一部でArray.prototype.atを使うように (#11274)

* refactor: `Array.prototype.at`を使うように

* fixup! refactor: `Array.prototype.at`を使うように

packages/backend/src/core/chart/core.ts

@@ -627,7 +627,7 @@ export default abstract class Chart<T extends Schema> {
 			}
 
 		// 要求された範囲の最も古い箇所に位置するログが存在しなかったら
-		} else if (!isTimeSame(new Date(logs[logs.length - 1].date * 1000), gt)) {
+		} else if (!isTimeSame(new Date(logs.at(-1)!.date * 1000), gt)) {
 			// 要求された範囲の最も古い箇所時点での最も新しいログを持ってきて末尾に追加する
 			// (隙間埋めできないため)
 			const outdatedLog = await repository.findOne({

packages/backend/src/misc/prelude/array.ts

@@ -67,8 +67,9 @@ export function maximum(xs: number[]): number {
 export function groupBy<T>(f: EndoRelation<T>, xs: T[]): T[][] {
 	const groups = [] as T[][];
 	for (const x of xs) {
-		if (groups.length !== 0 && f(groups[groups.length - 1][0], x)) {
-			groups[groups.length - 1].push(x);
+		const lastGroup = groups.at(-1);
+		if (lastGroup !== undefined && f(lastGroup[0], x)) {
+			lastGroup.push(x);
 		} else {
 			groups.push([x]);
 		}

packages/backend/src/queue/processors/CleanRemoteFilesProcessorService.ts

@@ -1,7 +1,7 @@
 import { Inject, Injectable } from '@nestjs/common';
 import { IsNull, MoreThan, Not } from 'typeorm';
 import { DI } from '@/di-symbols.js';
-import type { DriveFilesRepository } from '@/models/index.js';
+import type { DriveFile, DriveFilesRepository } from '@/models/index.js';
 import type { Config } from '@/config.js';
 import type Logger from '@/logger.js';
 import { DriveService } from '@/core/DriveService.js';
@@ -31,7 +31,7 @@ export class CleanRemoteFilesProcessorService {
 		this.logger.info('Deleting cached remote files...');
 
 		let deletedCount = 0;
-		let cursor: any = null;
+		let cursor: DriveFile['id'] | null = null;
 
 		while (true) {
 			const files = await this.driveFilesRepository.find({
@@ -51,7 +51,7 @@ export class CleanRemoteFilesProcessorService {
 				break;
 			}
 
-			cursor = files[files.length - 1].id;
+			cursor = files.at(-1)?.id ?? null;
 
 			await Promise.all(files.map(file => this.driveService.deleteFileSync(file, true)));
 

packages/backend/src/queue/processors/DeleteAccountProcessorService.ts

@@ -70,7 +70,7 @@ export class DeleteAccountProcessorService {
 					break;
 				}
 
-				cursor = notes[notes.length - 1].id;
+				cursor = notes.at(-1)?.id ?? null;
 
 				await this.notesRepository.delete(notes.map(note => note.id));
 
@@ -101,7 +101,7 @@ export class DeleteAccountProcessorService {
 					break;
 				}
 
-				cursor = files[files.length - 1].id;
+				cursor = files.at(-1)?.id ?? null;
 
 				for (const file of files) {
 					await this.driveService.deleteFileSync(file);

packages/backend/src/queue/processors/DeleteDriveFilesProcessorService.ts

@@ -1,7 +1,7 @@
 import { Inject, Injectable } from '@nestjs/common';
 import { MoreThan } from 'typeorm';
 import { DI } from '@/di-symbols.js';
-import type { UsersRepository, DriveFilesRepository } from '@/models/index.js';
+import type { UsersRepository, DriveFilesRepository, DriveFile } from '@/models/index.js';
 import type { Config } from '@/config.js';
 import type Logger from '@/logger.js';
 import { DriveService } from '@/core/DriveService.js';
@@ -40,7 +40,7 @@ export class DeleteDriveFilesProcessorService {
 		}
 
 		let deletedCount = 0;
-		let cursor: any = null;
+		let cursor: DriveFile['id'] | null = null;
 
 		while (true) {
 			const files = await this.driveFilesRepository.find({
@@ -59,7 +59,7 @@ export class DeleteDriveFilesProcessorService {
 				break;
 			}
 
-			cursor = files[files.length - 1].id;
+			cursor = files.at(-1)?.id ?? null;
 
 			for (const file of files) {
 				await this.driveService.deleteFileSync(file);

packages/backend/src/queue/processors/ExportBlockingProcessorService.ts

@@ -3,7 +3,7 @@ import { Inject, Injectable } from '@nestjs/common';
 import { MoreThan } from 'typeorm';
 import { format as dateFormat } from 'date-fns';
 import { DI } from '@/di-symbols.js';
-import type { UsersRepository, BlockingsRepository } from '@/models/index.js';
+import type { UsersRepository, BlockingsRepository, Blocking } from '@/models/index.js';
 import type { Config } from '@/config.js';
 import type Logger from '@/logger.js';
 import { DriveService } from '@/core/DriveService.js';
@@ -53,7 +53,7 @@ export class ExportBlockingProcessorService {
 			const stream = fs.createWriteStream(path, { flags: 'a' });
 
 			let exportedCount = 0;
-			let cursor: any = null;
+			let cursor: Blocking['id'] | null = null;
 
 			while (true) {
 				const blockings = await this.blockingsRepository.find({
@@ -72,7 +72,7 @@ export class ExportBlockingProcessorService {
 					break;
 				}
 
-				cursor = blockings[blockings.length - 1].id;
+				cursor = blockings.at(-1)?.id ?? null;
 
 				for (const block of blockings) {
 					const u = await this.usersRepository.findOneBy({ id: block.blockeeId });

packages/backend/src/queue/processors/ExportFavoritesProcessorService.ts

@@ -94,7 +94,7 @@ export class ExportFavoritesProcessorService {
 					break;
 				}
 
-				cursor = favorites[favorites.length - 1].id;
+				cursor = favorites.at(-1)?.id ?? null;
 
 				for (const favorite of favorites) {
 					let poll: Poll | undefined;

packages/backend/src/queue/processors/ExportFollowingProcessorService.ts

@@ -79,7 +79,7 @@ export class ExportFollowingProcessorService {
 					break;
 				}
 
-				cursor = followings[followings.length - 1].id;
+				cursor = followings.at(-1)?.id ?? null;
 
 				for (const following of followings) {
 					const u = await this.usersRepository.findOneBy({ id: following.followeeId });

packages/backend/src/queue/processors/ExportMutingProcessorService.ts

@@ -3,7 +3,7 @@ import { Inject, Injectable } from '@nestjs/common';
 import { IsNull, MoreThan } from 'typeorm';
 import { format as dateFormat } from 'date-fns';
 import { DI } from '@/di-symbols.js';
-import type { MutingsRepository, UsersRepository, BlockingsRepository } from '@/models/index.js';
+import type { MutingsRepository, UsersRepository, BlockingsRepository, Muting } from '@/models/index.js';
 import type { Config } from '@/config.js';
 import type Logger from '@/logger.js';
 import { DriveService } from '@/core/DriveService.js';
@@ -56,7 +56,7 @@ export class ExportMutingProcessorService {
 			const stream = fs.createWriteStream(path, { flags: 'a' });
 
 			let exportedCount = 0;
-			let cursor: any = null;
+			let cursor: Muting['id'] | null = null;
 
 			while (true) {
 				const mutes = await this.mutingsRepository.find({
@@ -76,7 +76,7 @@ export class ExportMutingProcessorService {
 					break;
 				}
 
-				cursor = mutes[mutes.length - 1].id;
+				cursor = mutes.at(-1)?.id ?? null;
 
 				for (const mute of mutes) {
 					const u = await this.usersRepository.findOneBy({ id: mute.muteeId });

packages/backend/src/queue/processors/ExportNotesProcessorService.ts

@@ -90,7 +90,7 @@ export class ExportNotesProcessorService {
 					break;
 				}
 
-				cursor = notes[notes.length - 1].id;
+				cursor = notes.at(-1)?.id ?? null;
 
 				for (const note of notes) {
 					let poll: Poll | undefined;

packages/backend/src/server/ActivityPubServerService.ts

@@ -181,7 +181,7 @@ export class ActivityPubServerService {
 				undefined,
 				inStock ? `${partOf}?${url.query({
 					page: 'true',
-					cursor: followings[followings.length - 1].id,
+					cursor: followings.at(-1)!.id,
 				})}` : undefined,
 			);
 
@@ -273,7 +273,7 @@ export class ActivityPubServerService {
 				undefined,
 				inStock ? `${partOf}?${url.query({
 					page: 'true',
-					cursor: followings[followings.length - 1].id,
+					cursor: followings.at(-1)!.id,
 				})}` : undefined,
 			);
 
@@ -398,7 +398,7 @@ export class ActivityPubServerService {
 				})}` : undefined,
 				notes.length ? `${partOf}?${url.query({
 					page: 'true',
-					until_id: notes[notes.length - 1].id,
+					until_id: notes.at(-1)!.id,
 				})}` : undefined,
 			);
 

packages/backend/test/utils.ts

@@ -447,12 +447,12 @@ export async function testPaginationConsistency<Entity extends { id: string, cre
 	for (const limit of [1, 5, 10, 100, undefined]) {
 		// 1. sinceId/DateとuntilId/Dateで両端を指定して取得した結果が期待通りになっていること
 		if (ordering === 'desc') {
-			const end = expected[expected.length - 1];
+			const end = expected.at(-1)!;
 			let last = await fetchEntities(rangeToParam({ limit, since: end }));
 			const actual: Entity[] = [];
 			while (last.length !== 0) {
 				actual.push(...last);
-				last = await fetchEntities(rangeToParam({ limit, until: last[last.length - 1], since: end }));
+				last = await fetchEntities(rangeToParam({ limit, until: last.at(-1), since: end }));
 			}
 			actual.push(end);
 			assert.deepStrictEqual(
@@ -467,7 +467,7 @@ export async function testPaginationConsistency<Entity extends { id: string, cre
 			const actual: Entity[] = [];
 			while (last.length !== 0) {
 				actual.push(...last);
-				last = await fetchEntities(rangeToParam({ limit, since: last[last.length - 1] }));
+				last = await fetchEntities(rangeToParam({ limit, since: last.at(-1) }));
 			}
 			assert.deepStrictEqual(
 				actual.map(({ id, createdAt }) => id + ':' + createdAt),
@@ -480,7 +480,7 @@ export async function testPaginationConsistency<Entity extends { id: string, cre
 			const actual: Entity[] = [];
 			while (last.length !== 0) {
 				actual.push(...last);
-				last = await fetchEntities(rangeToParam({ limit, until: last[last.length - 1] }));
+				last = await fetchEntities(rangeToParam({ limit, until: last.at(-1) }));
 			}
 			assert.deepStrictEqual(
 				actual.map(({ id, createdAt }) => id + ':' + createdAt),

packages/frontend/src/components/MkDrive.vue

@@ -568,7 +568,7 @@ function fetchMoreFolders() {
 	os.api('drive/folders', {
 		folderId: folder.value ? folder.value.id : null,
 		type: props.type,
-		untilId: folders.value[folders.value.length - 1].id,
+		untilId: folders.value.at(-1)?.id,
 		limit: max + 1,
 	}).then(folders => {
 		if (folders.length === max + 1) {
@@ -591,7 +591,7 @@ function fetchMoreFiles() {
 	os.api('drive/files', {
 		folderId: folder.value ? folder.value.id : null,
 		type: props.type,
-		untilId: files.value[files.value.length - 1].id,
+		untilId: files.value.at(-1)?.id,
 		limit: max + 1,
 	}).then(files => {
 		if (files.length === max + 1) {

packages/frontend/src/components/MkMiniChart.vue

@@ -59,8 +59,8 @@ function draw(): void {
 
 	polygonPoints = `0,${ viewBoxY } ${ polylinePoints } ${ viewBoxX },${ viewBoxY }`;
 
-	headX = _polylinePoints[_polylinePoints.length - 1][0];
-	headY = _polylinePoints[_polylinePoints.length - 1][1];
+	headX = _polylinePoints.at(-1)![0];
+	headY = _polylinePoints.at(-1)![1];
 }
 
 watch(() => props.src, draw, { immediate: true });

packages/frontend/src/components/MkPageWindow.vue

@@ -120,7 +120,7 @@ const contextmenu = $computed(() => ([{
 
 function back() {
 	history.pop();
-	router.replace(history[history.length - 1].path, history[history.length - 1].key);
+	router.replace(history.at(-1)!.path, history.at(-1)!.key);
 }
 
 function reload() {

packages/frontend/src/components/MkPagination.vue

@@ -233,7 +233,7 @@ const fetchMore = async (): Promise<void> => {
 		...(props.pagination.offsetMode ? {
 			offset: offset.value,
 		} : {
-			untilId: Array.from(items.value.keys())[items.value.size - 1],
+			untilId: Array.from(items.value.keys()).at(-1),
 		}),
 	}).then(res => {
 		for (let i = 0; i < res.length; i++) {
@@ -297,7 +297,7 @@ const fetchMoreAhead = async (): Promise<void> => {
 		...(props.pagination.offsetMode ? {
 			offset: offset.value,
 		} : {
-			sinceId: Array.from(items.value.keys())[items.value.size - 1],
+			sinceId: Array.from(items.value.keys()).at(-1),
 		}),
 	}).then(res => {
 		if (res.length === 0) {

packages/frontend/src/scripts/array.ts

@@ -78,8 +78,9 @@ export function maximum(xs: number[]): number {
 export function groupBy<T>(f: EndoRelation<T>, xs: T[]): T[][] {
 	const groups = [] as T[][];
 	for (const x of xs) {
-		if (groups.length !== 0 && f(groups[groups.length - 1][0], x)) {
-			groups[groups.length - 1].push(x);
+		const lastGroup = groups.at(-1);
+		if (lastGroup !== undefined && f(lastGroup[0], x)) {
+			lastGroup.push(x);
 		} else {
 			groups.push([x]);
 		}

packages/frontend/src/widgets/server-metric/cpu-mem.vue

@@ -121,10 +121,10 @@ function onStats(connStats) {
 	cpuPolygonPoints = `${viewBoxX - (stats.length - 1)},${viewBoxY} ${cpuPolylinePoints} ${viewBoxX},${viewBoxY}`;
 	memPolygonPoints = `${viewBoxX - (stats.length - 1)},${viewBoxY} ${memPolylinePoints} ${viewBoxX},${viewBoxY}`;
 
-	cpuHeadX = cpuPolylinePointsStats[cpuPolylinePointsStats.length - 1][0];
-	cpuHeadY = cpuPolylinePointsStats[cpuPolylinePointsStats.length - 1][1];
-	memHeadX = memPolylinePointsStats[memPolylinePointsStats.length - 1][0];
-	memHeadY = memPolylinePointsStats[memPolylinePointsStats.length - 1][1];
+	cpuHeadX = cpuPolylinePointsStats.at(-1)![0];
+	cpuHeadY = cpuPolylinePointsStats.at(-1)![1];
+	memHeadX = memPolylinePointsStats.at(-1)![0];
+	memHeadY = memPolylinePointsStats.at(-1)![1];
 
 	cpuP = (connStats.cpu * 100).toFixed(0);
 	memP = (connStats.mem.active / props.meta.mem.total * 100).toFixed(0);

packages/frontend/src/widgets/server-metric/net.vue

@@ -94,10 +94,10 @@ function onStats(connStats) {
 	inPolygonPoints = `${viewBoxX - (stats.length - 1)},${viewBoxY} ${inPolylinePoints} ${viewBoxX},${viewBoxY}`;
 	outPolygonPoints = `${viewBoxX - (stats.length - 1)},${viewBoxY} ${outPolylinePoints} ${viewBoxX},${viewBoxY}`;
 
-	inHeadX = inPolylinePointsStats[inPolylinePointsStats.length - 1][0];
-	inHeadY = inPolylinePointsStats[inPolylinePointsStats.length - 1][1];
-	outHeadX = outPolylinePointsStats[outPolylinePointsStats.length - 1][0];
-	outHeadY = outPolylinePointsStats[outPolylinePointsStats.length - 1][1];
+	inHeadX = inPolylinePointsStats.at(-1)![0];
+	inHeadY = inPolylinePointsStats.at(-1)![1];
+	outHeadX = outPolylinePointsStats.at(-1)![0];
+	outHeadY = outPolylinePointsStats.at(-1)![1];
 
 	inRecent = connStats.net.rx;
 	outRecent = connStats.net.tx;