Improve error handling of API (#4345)

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* Update attached_notes.ts

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* Refactor

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* Update call.ts

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* :v:

* Fix

16 files changed, 237 insertions, 147 deletions

diff --git a/src/server/api/endpoints/users/followers.ts b/src/server/api/endpoints/users/followers.ts
index 2f7f1af6a5..cb5b047626 100644
--- a/src/server/api/endpoints/users/followers.ts
+++ b/src/server/api/endpoints/users/followers.ts
@@ -5,6 +5,7 @@ import Following from '../../../../models/following';
 import { pack } from '../../../../models/user';
 import { getFriendIds } from '../../common/get-friends';
 import define from '../../define';
+import { ApiError } from '../../error';
 
 export const meta = {
 	desc: {
@@ -47,10 +48,18 @@ export const meta = {
 			validator: $.optional.bool,
 			default: false,
 		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '27fa5435-88ab-43de-9360-387de88727cd'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	const q: any = ps.userId != null
 		? { _id: ps.userId }
 		: { usernameLower: ps.username.toLowerCase(), host: ps.host };
@@ -58,10 +67,9 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	const user = await User.findOne(q);
 
 	if (user === null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
-	// Construct query
 	const query = {
 		followeeId: user._id
 	} as any;
@@ -98,8 +106,8 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 
 	const users = await Promise.all(following.map(f => pack(f.followerId, me, { detail: true })));
 
-	res({
+	return {
 		users: users,
 		next: inStock ? following[following.length - 1]._id : null,
-	});
-}));
+	};
+});
diff --git a/src/server/api/endpoints/users/following.ts b/src/server/api/endpoints/users/following.ts
index 1485a63f24..04abe5f4b3 100644
--- a/src/server/api/endpoints/users/following.ts
+++ b/src/server/api/endpoints/users/following.ts
@@ -5,6 +5,7 @@ import Following from '../../../../models/following';
 import { pack } from '../../../../models/user';
 import { getFriendIds } from '../../common/get-friends';
 import define from '../../define';
+import { ApiError } from '../../error';
 
 export const meta = {
 	desc: {
@@ -47,10 +48,18 @@ export const meta = {
 			validator: $.optional.bool,
 			default: false,
 		}
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '63e4aba4-4156-4e53-be25-c9559e42d71b'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	const q: any = ps.userId != null
 		? { _id: ps.userId }
 		: { usernameLower: ps.username.toLowerCase(), host: ps.host };
@@ -58,10 +67,9 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	const user = await User.findOne(q);
 
 	if (user === null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
-	// Construct query
 	const query = {
 		followerId: user._id
 	} as any;
@@ -98,8 +106,8 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 
 	const users = await Promise.all(following.map(f => pack(f.followeeId, me, { detail: true })));
 
-	res({
+	return {
 		users: users,
 		next: inStock ? following[following.length - 1]._id : null,
-	});
-}));
+	};
+});
diff --git a/src/server/api/endpoints/users/get_frequently_replied_users.ts b/src/server/api/endpoints/users/get_frequently_replied_users.ts
index e897fe8db2..b20d1ef69e 100644
--- a/src/server/api/endpoints/users/get_frequently_replied_users.ts
+++ b/src/server/api/endpoints/users/get_frequently_replied_users.ts
@@ -5,6 +5,7 @@ import User, { pack } from '../../../../models/user';
 import define from '../../define';
 import { maximum } from '../../../../prelude/array';
 import { getHideUserIds } from '../../common/get-hide-users';
+import { ApiError } from '../../error';
 
 export const meta = {
 	requireCredential: false,
@@ -23,10 +24,18 @@ export const meta = {
 			validator: $.optional.num.range(1, 100),
 			default: 10
 		},
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'e6965129-7b2a-40a4-bae2-cd84cd434822'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	// Lookup user
 	const user = await User.findOne({
 		_id: ps.userId
@@ -37,7 +46,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (user === null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
 	// Fetch recent notes
@@ -60,7 +69,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 
 	// 投稿が少なかったら中断
 	if (recentNotes.length === 0) {
-		return res([]);
+		return [];
 	}
 
 	const hideUserIds = await getHideUserIds(me);
@@ -106,5 +115,5 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		weight: repliedUsers[user] / peak
 	})));
 
-	res(repliesObj);
-}));
+	return repliesObj;
+});
diff --git a/src/server/api/endpoints/users/lists/create.ts b/src/server/api/endpoints/users/lists/create.ts
index d93cf13d94..a3d91b6c25 100644
--- a/src/server/api/endpoints/users/lists/create.ts
+++ b/src/server/api/endpoints/users/lists/create.ts
@@ -19,8 +19,7 @@ export const meta = {
 	}
 };
 
-export default define(meta, (ps, user) => new Promise(async (res, rej) => {
-	// insert
+export default define(meta, async (ps, user) => {
 	const userList = await UserList.insert({
 		createdAt: new Date(),
 		userId: user._id,
@@ -28,6 +27,5 @@ export default define(meta, (ps, user) => new Promise(async (res, rej) => {
 		userIds: []
 	});
 
-	// Response
-	res(await pack(userList));
-}));
+	return await pack(userList);
+});
diff --git a/src/server/api/endpoints/users/lists/delete.ts b/src/server/api/endpoints/users/lists/delete.ts
index 8d297198c9..6aaf4701d4 100644
--- a/src/server/api/endpoints/users/lists/delete.ts
+++ b/src/server/api/endpoints/users/lists/delete.ts
@@ -2,6 +2,7 @@ import $ from 'cafy';
 import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList from '../../../../../models/user-list';
 import define from '../../../define';
+import { ApiError } from '../../../error';
 
 export const meta = {
 	desc: {
@@ -22,22 +23,28 @@ export const meta = {
 				'en-US': 'ID of target user list'
 			}
 		}
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '78436795-db79-42f5-b1e2-55ea2cf19166'
+		}
 	}
 };
 
-export default define(meta, (ps, user) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, user) => {
 	const userList = await UserList.findOne({
 		_id: ps.listId,
 		userId: user._id
 	});
 
 	if (userList == null) {
-		return rej('list not found');
+		throw new ApiError(meta.errors.noSuchList);
 	}
 
 	await UserList.remove({
 		_id: userList._id
 	});
-
-	res();
-}));
+});
diff --git a/src/server/api/endpoints/users/lists/list.ts b/src/server/api/endpoints/users/lists/list.ts
index 8f9775e19b..5bd662878d 100644
--- a/src/server/api/endpoints/users/lists/list.ts
+++ b/src/server/api/endpoints/users/lists/list.ts
@@ -11,11 +11,10 @@ export const meta = {
 	kind: 'account-read'
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
-	// Fetch lists
+export default define(meta, async (ps, me) => {
 	const userLists = await UserList.find({
 		userId: me._id,
 	});
 
-	res(await Promise.all(userLists.map(x => pack(x))));
-}));
+	return await Promise.all(userLists.map(x => pack(x)));
+});
diff --git a/src/server/api/endpoints/users/lists/pull.ts b/src/server/api/endpoints/users/lists/pull.ts
index 86eaa1dd8d..416c1b4b2d 100644
--- a/src/server/api/endpoints/users/lists/pull.ts
+++ b/src/server/api/endpoints/users/lists/pull.ts
@@ -4,6 +4,7 @@ import UserList from '../../../../../models/user-list';
 import User, { pack as packUser } from '../../../../../models/user';
 import { publishUserListStream } from '../../../../../services/stream';
 import define from '../../../define';
+import { ApiError } from '../../../error';
 
 export const meta = {
 	desc: {
@@ -29,10 +30,24 @@ export const meta = {
 				'en-US': 'Target user ID'
 			}
 		},
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '7f44670e-ab16-43b8-b4c1-ccd2ee89cc02'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '588e7f72-c744-4a61-b180-d354e912bda2'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserList.findOne({
 		_id: ps.listId,
@@ -40,7 +55,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (userList == null) {
-		return rej('list not found');
+		throw new ApiError(meta.errors.noSuchList);
 	}
 
 	// Fetch the user
@@ -49,7 +64,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (user == null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
 	// Pull the user
@@ -59,7 +74,5 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		}
 	});
 
-	res();
-
 	publishUserListStream(userList._id, 'userRemoved', await packUser(user));
-}));
+});
diff --git a/src/server/api/endpoints/users/lists/push.ts b/src/server/api/endpoints/users/lists/push.ts
index 6e2dbed518..90dd2aa045 100644
--- a/src/server/api/endpoints/users/lists/push.ts
+++ b/src/server/api/endpoints/users/lists/push.ts
@@ -7,6 +7,7 @@ import { renderActivity } from '../../../../../remote/activitypub/renderer';
 import renderFollow from '../../../../../remote/activitypub/renderer/follow';
 import { deliver } from '../../../../../queue';
 import define from '../../../define';
+import { ApiError } from '../../../error';
 
 export const meta = {
 	desc: {
@@ -32,10 +33,30 @@ export const meta = {
 				'en-US': 'Target user ID'
 			}
 		},
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '2214501d-ac96-4049-b717-91e42272a711'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: 'a89abd3d-f0bc-4cce-beb1-2f446f4f1e6a'
+		},
+
+		alreadyAdded: {
+			message: 'That user has already been added to that list.',
+			code: 'ALREADY_ADDED',
+			id: '1de7c884-1595-49e9-857e-61f12f4d4fc5'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserList.findOne({
 		_id: ps.listId,
@@ -43,7 +64,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (userList == null) {
-		return rej('list not found');
+		throw new ApiError(meta.errors.noSuchList);
 	}
 
 	// Fetch the user
@@ -52,11 +73,11 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (user == null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
 	if (userList.userIds.map(id => id.toHexString()).includes(user._id.toHexString())) {
-		return rej('the user already added');
+		throw new ApiError(meta.errors.alreadyAdded);
 	}
 
 	// Push the user
@@ -66,8 +87,6 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		}
 	});
 
-	res();
-
 	publishUserListStream(userList._id, 'userAdded', await packUser(user));
 
 	// このインスタンス内にこのリモートユーザーをフォローしているユーザーがいなくても投稿を受け取るためにダミーのユーザーがフォローしたということにする
@@ -76,4 +95,4 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		const content = renderActivity(renderFollow(proxy, user));
 		deliver(proxy, content, user.inbox);
 	}
-}));
+});
diff --git a/src/server/api/endpoints/users/lists/show.ts b/src/server/api/endpoints/users/lists/show.ts
index c508659a15..3bd8ce6573 100644
--- a/src/server/api/endpoints/users/lists/show.ts
+++ b/src/server/api/endpoints/users/lists/show.ts
@@ -2,6 +2,7 @@ import $ from 'cafy';
 import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList, { pack } from '../../../../../models/user-list';
 import define from '../../../define';
+import { ApiError } from '../../../error';
 
 export const meta = {
 	desc: {
@@ -18,10 +19,18 @@ export const meta = {
 			validator: $.type(ID),
 			transform: transform,
 		},
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '7bc05c21-1d7a-41ae-88f1-66820f4dc686'
+		},
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	// Fetch the list
 	const userList = await UserList.findOne({
 		_id: ps.listId,
@@ -29,8 +38,8 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	});
 
 	if (userList == null) {
-		return rej('list not found');
+		throw new ApiError(meta.errors.noSuchList);
 	}
 
-	res(await pack(userList));
-}));
+	return await pack(userList);
+});
diff --git a/src/server/api/endpoints/users/lists/update.ts b/src/server/api/endpoints/users/lists/update.ts
index 79a7da5658..842ae189ee 100644
--- a/src/server/api/endpoints/users/lists/update.ts
+++ b/src/server/api/endpoints/users/lists/update.ts
@@ -2,6 +2,7 @@ import $ from 'cafy';
 import ID, { transform } from '../../../../../misc/cafy-id';
 import UserList, { pack } from '../../../../../models/user-list';
 import define from '../../../define';
+import { ApiError } from '../../../error';
 
 export const meta = {
 	desc: {
@@ -30,10 +31,18 @@ export const meta = {
 				'en-US': 'name of this user list'
 			}
 		}
+	},
+
+	errors: {
+		noSuchList: {
+			message: 'No such list.',
+			code: 'NO_SUCH_LIST',
+			id: '796666fe-3dff-4d39-becb-8a5932c1d5b7'
+		},
 	}
 };
 
-export default define(meta, (ps, user) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, user) => {
 	// Fetch the list
 	const userList = await UserList.findOne({
 		_id: ps.listId,
@@ -41,16 +50,14 @@ export default define(meta, (ps, user) => new Promise(async (res, rej) => {
 	});
 
 	if (userList == null) {
-		return rej('list not found');
+		throw new ApiError(meta.errors.noSuchList);
 	}
 
-	// update
 	await UserList.update({ _id: userList._id }, {
 		$set: {
 			title: ps.title
 		}
 	});
 
-	// Response
-	res(await pack(userList._id));
-}));
+	return await pack(userList._id);
+});
diff --git a/src/server/api/endpoints/users/notes.ts b/src/server/api/endpoints/users/notes.ts
index 5c776e48e2..98d67e865a 100644
--- a/src/server/api/endpoints/users/notes.ts
+++ b/src/server/api/endpoints/users/notes.ts
@@ -1,11 +1,10 @@
 import $ from 'cafy';
 import ID, { transform } from '../../../../misc/cafy-id';
-import getHostLower from '../../common/get-host-lower';
 import Note, { packMany } from '../../../../models/note';
 import User from '../../../../models/user';
 import define from '../../define';
-import { countIf } from '../../../../prelude/array';
 import Following from '../../../../models/following';
+import { ApiError } from '../../error';
 
 export const meta = {
 	desc: {
@@ -14,7 +13,7 @@ export const meta = {
 
 	params: {
 		userId: {
-			validator: $.optional.type(ID),
+			validator: $.type(ID),
 			transform: transform,
 			desc: {
 				'ja-JP': '対象のユーザーのID',
@@ -22,17 +21,6 @@ export const meta = {
 			}
 		},
 
-		username: {
-			validator: $.optional.str,
-			desc: {
-				'ja-JP': 'ユーザー名'
-			}
-		},
-
-		host: {
-			validator: $.optional.nullable.str,
-		},
-
 		includeReplies: {
 			validator: $.optional.bool,
 			default: true,
@@ -134,32 +122,27 @@ export const meta = {
 				'ja-JP': 'true にすると、NSFW指定されたファイルを除外します(fileTypeが指定されている場合のみ有効)'
 			}
 		},
-	}
-};
-
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
-	if (ps.userId === undefined && ps.username === undefined) {
-		return rej('userId or username is required');
-	}
+	},
 
-	// Check if only one of sinceId, untilId, sinceDate, untilDate specified
-	if (countIf(x => x != null, [ps.sinceId, ps.untilId, ps.sinceDate, ps.untilDate]) > 1) {
-		throw 'only one of sinceId, untilId, sinceDate, untilDate can be specified';
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '27e494ba-2ac2-48e8-893b-10d4d8c2387b'
+		}
 	}
+};
 
-	const q = ps.userId != null
-		? { _id: ps.userId }
-		: { usernameLower: ps.username.toLowerCase(), host: getHostLower(ps.host) } ;
-
+export default define(meta, async (ps, me) => {
 	// Lookup user
-	const user = await User.findOne(q, {
+	const user = await User.findOne({ _id: ps.userId }, {
 		fields: {
 			_id: true
 		}
 	});
 
 	if (user === null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
 	const isFollowing = me == null ? false : ((await Following.findOne({
@@ -259,13 +242,10 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 	}
 	//#endregion
 
-	// Issue query
-	const notes = await Note
-		.find(query, {
-			limit: ps.limit,
-			sort: sort
-		});
+	const notes = await Note.find(query, {
+		limit: ps.limit,
+		sort: sort
+	});
 
-	// Serialize
-	res(await packMany(notes, me));
-}));
+	return await packMany(notes, me);
+});
diff --git a/src/server/api/endpoints/users/recommendation.ts b/src/server/api/endpoints/users/recommendation.ts
index e9f0107716..dc37bc56ba 100644
--- a/src/server/api/endpoints/users/recommendation.ts
+++ b/src/server/api/endpoints/users/recommendation.ts
@@ -32,7 +32,7 @@ export const meta = {
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	const instance = await fetchMeta();
 
 	if (instance.enableExternalUserRecommendation) {
@@ -48,7 +48,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 			.replace('{{limit}}', limit.toString())
 			.replace('{{offset}}', offset.toString());
 
-		request({
+		const users = await request({
 			url: url,
 			proxy: config.proxy,
 			timeout: timeout,
@@ -56,37 +56,36 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 			followRedirect: true,
 			followAllRedirects: true
 		})
-			.then(body => convertUsers(body, me))
-			.then(packed => res(packed))
-			.catch(e => rej(e));
+		.then(body => convertUsers(body, me));
+
+		return users;
 	} else {
 		// ID list of the user itself and other users who the user follows
 		const followingIds = await getFriendIds(me._id);
 
-	// 隠すユーザーを取得
-	const hideUserIds = await getHideUserIds(me);
+		// 隠すユーザーを取得
+		const hideUserIds = await getHideUserIds(me);
 
-		const users = await User
-			.find({
-				_id: {
-					$nin: followingIds.concat(hideUserIds)
-				},
-				isLocked: { $ne: true },
-				updatedAt: {
-					$gte: new Date(Date.now() - ms('7days'))
-				},
-				host: null
-			}, {
-				limit: ps.limit,
-				skip: ps.offset,
-				sort: {
-					followersCount: -1
-				}
-			});
+		const users = await User.find({
+			_id: {
+				$nin: followingIds.concat(hideUserIds)
+			},
+			isLocked: { $ne: true },
+			updatedAt: {
+				$gte: new Date(Date.now() - ms('7days'))
+			},
+			host: null
+		}, {
+			limit: ps.limit,
+			skip: ps.offset,
+			sort: {
+				followersCount: -1
+			}
+		});
 
-		res(await Promise.all(users.map(user => pack(user, me, { detail: true }))));
+		return await Promise.all(users.map(user => pack(user, me, { detail: true })));
 	}
-}));
+});
 
 type IRecommendUser = {
 	name: string;
diff --git a/src/server/api/endpoints/users/relation.ts b/src/server/api/endpoints/users/relation.ts
index 43d5e70640..5b7b4d8e4d 100644
--- a/src/server/api/endpoints/users/relation.ts
+++ b/src/server/api/endpoints/users/relation.ts
@@ -21,10 +21,10 @@ export const meta = {
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	const ids = Array.isArray(ps.userId) ? ps.userId : [ps.userId];
 
 	const relations = await Promise.all(ids.map(id => getRelation(me._id, id)));
 
-	res(Array.isArray(ps.userId) ? relations : relations[0]);
-}));
+	return Array.isArray(ps.userId) ? relations : relations[0];
+});
diff --git a/src/server/api/endpoints/users/report-abuse.ts b/src/server/api/endpoints/users/report-abuse.ts
index c592e5cfd4..32a2393493 100644
--- a/src/server/api/endpoints/users/report-abuse.ts
+++ b/src/server/api/endpoints/users/report-abuse.ts
@@ -4,6 +4,7 @@ import define from '../../define';
 import User from '../../../../models/user';
 import AbuseUserReport from '../../../../models/abuse-user-report';
 import { publishAdminStream } from '../../../../services/stream';
+import { ApiError } from '../../error';
 
 export const meta = {
 	desc: {
@@ -28,25 +29,45 @@ export const meta = {
 				'ja-JP': '迷惑行為の詳細'
 			}
 		},
+	},
+
+	errors: {
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '1acefcb5-0959-43fd-9685-b48305736cb5'
+		},
+
+		cannotReportYourself: {
+			message: 'Cannot report yourself.',
+			code: 'CANNOT_REPORT_YOURSELF',
+			id: '1e13149e-b1e8-43cf-902e-c01dbfcb202f'
+		},
+
+		cannotReportAdmin: {
+			message: 'Cannot report the admin.',
+			code: 'CANNOT_REPORT_THE_ADMIN',
+			id: '35e166f5-05fb-4f87-a2d5-adb42676d48f'
+		}
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	// Lookup user
 	const user = await User.findOne({
 		_id: ps.userId
 	});
 
 	if (user === null) {
-		return rej('user not found');
+		throw new ApiError(meta.errors.noSuchUser);
 	}
 
 	if (user._id.equals(me._id)) {
-		return rej('cannot report yourself');
+		throw new ApiError(meta.errors.cannotReportYourself);
 	}
 
 	if (user.isAdmin) {
-		return rej('cannot report admin');
+		throw new ApiError(meta.errors.cannotReportAdmin);
 	}
 
 	const report = await AbuseUserReport.insert({
@@ -65,6 +86,7 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 				isModerator: true
 			}]
 		});
+
 		for (const moderator of moderators) {
 			publishAdminStream(moderator._id, 'newAbuseUserReport', {
 				id: report._id,
@@ -74,6 +96,4 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 			});
 		}
 	}, 1);
-
-	res();
-}));
+});
diff --git a/src/server/api/endpoints/users/search.ts b/src/server/api/endpoints/users/search.ts
index 5dc1e4aeab..6fd390f283 100644
--- a/src/server/api/endpoints/users/search.ts
+++ b/src/server/api/endpoints/users/search.ts
@@ -52,7 +52,7 @@ export const meta = {
 	},
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	const isUsername = validateUsername(ps.query.replace('@', ''), !ps.localOnly);
 
 	let users: IUser[] = [];
@@ -80,5 +80,5 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		}
 	}
 
-	res(await Promise.all(users.map(user => pack(user, me, { detail: ps.detail }))));
-}));
+	return await Promise.all(users.map(user => pack(user, me, { detail: ps.detail })));
+});
diff --git a/src/server/api/endpoints/users/show.ts b/src/server/api/endpoints/users/show.ts
index 025598b8ff..4f870b8b92 100644
--- a/src/server/api/endpoints/users/show.ts
+++ b/src/server/api/endpoints/users/show.ts
@@ -4,6 +4,7 @@ import User, { pack, isRemoteUser } from '../../../../models/user';
 import resolveRemoteUser from '../../../../remote/resolve-user';
 import define from '../../define';
 import { apiLogger } from '../../logger';
+import { ApiError } from '../../error';
 
 const cursorOption = { fields: { data: false } };
 
@@ -39,10 +40,25 @@ export const meta = {
 		host: {
 			validator: $.optional.nullable.str
 		}
+	},
+
+	errors: {
+		failedToResolveRemoteUser: {
+			message: 'Failed to resolve remote user.',
+			code: 'FAILED_TO_RESOLVE_REMOTE_USER',
+			id: 'ef7b9be4-9cba-4e6f-ab41-90ed171c7d3c',
+			kind: 'server' as 'server'
+		},
+
+		noSuchUser: {
+			message: 'No such user.',
+			code: 'NO_SUCH_USER',
+			id: '4362f8dc-731f-4ad8-a694-be5a88922a24'
+		},
 	}
 };
 
-export default define(meta, (ps, me) => new Promise(async (res, rej) => {
+export default define(meta, async (ps, me) => {
 	let user;
 
 	if (ps.userIds) {
@@ -52,18 +68,16 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 			}
 		});
 
-		res(await Promise.all(users.map(u => pack(u, me, {
+		return await Promise.all(users.map(u => pack(u, me, {
 			detail: true
-		}))));
+		})));
 	} else {
 		// Lookup user
 		if (typeof ps.host === 'string') {
-			try {
-				user = await resolveRemoteUser(ps.username, ps.host, cursorOption);
-			} catch (e) {
+			user = await resolveRemoteUser(ps.username, ps.host, cursorOption).catch(e => {
 				apiLogger.warn(`failed to resolve remote user: ${e}`);
-				return rej('failed to resolve remote user');
-			}
+				throw new ApiError(meta.errors.failedToResolveRemoteUser);
+			});
 		} else {
 			const q: any = ps.userId != null
 				? { _id: ps.userId }
@@ -73,18 +87,18 @@ export default define(meta, (ps, me) => new Promise(async (res, rej) => {
 		}
 
 		if (user === null) {
-			return rej('user not found');
+			throw new ApiError(meta.errors.noSuchUser);
 		}
 
-		// Send response
-		res(await pack(user, me, {
-			detail: true
-		}));
-
+		// ユーザー情報更新
 		if (isRemoteUser(user)) {
 			if (user.lastFetchedAt == null || Date.now() - user.lastFetchedAt.getTime() > 1000 * 60 * 60 * 24) {
 				resolveRemoteUser(ps.username, ps.host, { }, true);
 			}
 		}
+
+		return await pack(user, me, {
+			detail: true
+		});
 	}
-}));
+});