iceshrimp-legacy/packages/backend/src/misc/check-word-mute.ts

import RE2 from "re2";
import type { Note } from "@/models/entities/note.js";
import type { User } from "@/models/entities/user.js";

type NoteLike = {
	userId: Note["userId"];
	text: Note["text"];
};

type UserLike = {
	id: User["id"];
};

export async function checkWordMute(
	note: NoteLike,
	me: UserLike | null | undefined,
	mutedWords: Array<string | string[]>,
): Promise<boolean> {
	// 自分自身
	if (me && note.userId === me.id) return false;

	if (mutedWords.length > 0) {
		const text = ((note.cw ?? "") + "\n" + (note.text ?? "")).trim();

		if (text === "") return false;

		const matched = mutedWords.some((filter) => {
			if (Array.isArray(filter)) {
				return filter.every((keyword) => text.includes(keyword));
			} else {
				// represents RegExp
				const regexp = filter.match(/^\/(.+)\/(.*)$/);

				// This should never happen due to input sanitisation.
				if (!regexp) return false;

				try {
					return new RE2(regexp[1], regexp[2]).test(text);
				} catch (err) {
					// This should never happen due to input sanitisation.
					return false;
				}
			}
		});

		if (matched) return true;
	}

	return false;
}