fix(news): enforce shared comment publication and moderation rules

src/app/api/articles/[slug]/comment/route.ts

@@ -1,60 +1,52 @@
-// Public REST API — post a comment on an article as the Bearer-authed user.
-//
-// POST /api/articles/:slug/comment — looks up the website_article by slug for
-// its id, then inserts a website_article_comments row owned by the user behind
-// the Authorization: Bearer token. Comment is required, non-empty, max 255
-// chars (matches the VARCHAR(255) column). Fails soft — never returns a 500 for
-// DB issues, just a generic error envelope.
-
-import { eq } from "drizzle-orm";
-import { apiError, apiJson } from "@/lib/api";
+// Public REST API: comments belong to the authenticated Bearer token's user.
+import { apiError, apiJson, apiUnavailable } from "@/lib/api";
 import { bearerUserId } from "@/lib/api-auth";
-import { db, WebsiteArticleComments, WebsiteArticles } from "@/lib/db";
-import { rateLimit } from "@/lib/rate-limit";
+import { logger } from "@/lib/logger";
+import { submitArticleComment } from "@/lib/services/article-comment-submission";
 
 export async function POST(
 	req: Request,
 	{ params }: { params: Promise<{ slug: string }> },
 ) {
-	const uid = await bearerUserId(req, ["articles:write"]);
-	if (!uid) return apiError("Unauthorized", 401);
-
-	if (!(await rateLimit(`article-comment:${uid}`, 10, 60_000)).ok) {
-		return apiError("Too many comments. Please wait a minute.", 429);
-	}
-
-	const { slug } = await params;
-
-	const body = (await req.json().catch(() => ({}))) as { comment?: unknown };
-	const comment = typeof body.comment === "string" ? body.comment.trim() : "";
-	if (!comment) {
-		return apiError("Comment is required", 422);
-	}
-	if (comment.length > 255) {
-		return apiError("Comment may not be longer than 255 characters", 422);
-	}
-
 	try {
-		const [article] = await db
-			.select({ id: WebsiteArticles.id })
-			.from(WebsiteArticles)
-			.where(eq(WebsiteArticles.slug, slug))
-			.limit(1);
-		if (!article) {
-			return apiError("Article not found", 404);
-		}
-
-		const now = new Date();
-		await db.insert(WebsiteArticleComments).values({
-			articleId: article.id,
+		const uid = await bearerUserId(req, ["articles:write"]);
+		if (!uid) return apiError("Unauthorized", 401);
+		const { slug } = await params;
+		const body: unknown = await req.json().catch(() => null);
+		const result = await submitArticleComment({
 			userId: uid,
-			comment,
-			createdAt: now,
-			updatedAt: now,
+			target: { slug },
+			comment:
+				body && typeof body === "object" && "comment" in body
+					? body.comment
+					: undefined,
 		});
-
-		return apiJson({ ok: true });
+		if (result.ok) return apiJson({ ok: true });
+		switch (result.reason) {
+			case "ratelimit": {
+				const response = apiError(
+					"Too many comments. Please wait a minute.",
+					429,
+				);
+				response.headers.set("Retry-After", String(result.retryAfter ?? 30));
+				return response;
+			}
+			case "empty":
+				return apiError("Comment is required", 422);
+			case "too_long":
+				return apiError("Comment may not be longer than 255 characters", 422);
+			case "moderated":
+				return apiError("Comment was blocked by moderation", 422);
+			case "invalid":
+			case "not_found":
+				return apiError("Article not found", 404);
+		}
 	} catch {
-		return apiError("Could not post comment", 400);
+		// Driver errors may contain SQL and user content; log a safe diagnostic.
+		logger.error("Article comment submission failed", {
+			module: "article-comments",
+			channel: "api",
+		});
+		return apiUnavailable("Could not post comment");
 	}
 }

src/lib/services/article-comment-submission.ts

@@ -0,0 +1,87 @@
+import "server-only";
+import { and, eq, or, sql } from "drizzle-orm";
+import { db, WebsiteArticleComments, WebsiteArticles } from "@/lib/db";
+import { rateLimit } from "@/lib/rate-limit";
+import { isAllowed } from "@/lib/services/moderation";
+
+export type ArticleCommentTarget = { id: string } | { slug: string };
+export type ArticleCommentResult =
+	| { ok: true; slug: string }
+	| {
+			ok: false;
+			reason:
+				| "empty"
+				| "too_long"
+				| "invalid"
+				| "moderated"
+				| "ratelimit"
+				| "not_found";
+			retryAfter?: number;
+	  };
+
+/** Authenticated callers share the same quota and uncached publication check. */
+export async function submitArticleComment({
+	userId,
+	target,
+	comment: rawComment,
+}: {
+	userId: number;
+	target: ArticleCommentTarget;
+	comment: unknown;
+}): Promise<ArticleCommentResult> {
+	if (!Number.isSafeInteger(userId) || userId <= 0)
+		return { ok: false, reason: "invalid" };
+	// Preserve the site's five-attempt burst; API and form consume one bucket.
+	const limit = await rateLimit(`comment:${userId}`, 5, 30_000);
+	if (!limit.ok)
+		return { ok: false, reason: "ratelimit", retryAfter: limit.retryAfter };
+
+	const comment =
+		typeof rawComment === "string" ? rawComment.normalize("NFC").trim() : "";
+	if (!comment) return { ok: false, reason: "empty" };
+	if (comment.length > 255) return { ok: false, reason: "too_long" };
+
+	let articleId = 0n;
+	if ("id" in target) {
+		if (!/^\d{1,20}$/.test(target.id)) return { ok: false, reason: "invalid" };
+		articleId = BigInt(target.id);
+		if (articleId <= 0n || articleId > 18446744073709551615n)
+			return { ok: false, reason: "invalid" };
+	} else if (!target.slug || target.slug.length > 255) {
+		return { ok: false, reason: "invalid" };
+	}
+	if (!(await isAllowed(comment)).ok) return { ok: false, reason: "moderated" };
+
+	// Moderate before locking: the optional remote check can take several seconds.
+	// A locking read sees current publication state and serializes withdrawal/deletion
+	// with this insert, rather than trusting a prior page or cached article lookup.
+	return db.transaction(async (tx): Promise<ArticleCommentResult> => {
+		const [article] = await tx
+			.select({ id: WebsiteArticles.id, slug: WebsiteArticles.slug })
+			.from(WebsiteArticles)
+			.where(
+				and(
+					"slug" in target
+						? eq(WebsiteArticles.slug, target.slug)
+						: eq(WebsiteArticles.id, articleId),
+					eq(WebsiteArticles.status, "published"),
+					or(
+						sql`${WebsiteArticles.publishAt} IS NULL`,
+						sql`${WebsiteArticles.publishAt} <= NOW()`,
+					),
+				),
+			)
+			.limit(1)
+			.for("update");
+		if (!article) return { ok: false, reason: "not_found" };
+		const now = new Date();
+		await tx.insert(WebsiteArticleComments).values({
+			articleId: article.id,
+			userId,
+			comment,
+			createdAt: now,
+			updatedAt: now,
+		});
+		return { ok: true, slug: article.slug };
+	});
+}