Add PDF generation pipeline via browserless and Defuddle

Connects to browserless over CDP (playwright-core), extracts article
content with Defuddle/JSDOM, renders it through buildCleanHtml, and
prints a PDF on a second page. Adds an in-browser request filter as a
second line of SSRF defense against redirects to private/localhost
hosts, on top of assertPublicUrl's DNS check.

Integration test is gated by RUN_PDF_INTEGRATION=1 (describe.runIf) so
it is skipped in a normal npm run test and only runs against a real
browserless instance.

src/lib/clean-pdf/__tests__/generate.int.test.ts

@@ -0,0 +1,17 @@
+import { describe, expect, it } from "vitest";
+import { generateCleanPdf } from "@/lib/clean-pdf/generate";
+
+const enabled = process.env.RUN_PDF_INTEGRATION === "1";
+
+describe.runIf(enabled)("generateCleanPdf (integration, нужен browserless)", () => {
+  it("генерирует PDF реальной статьи", async () => {
+    const { pdf, title } = await generateCleanPdf({
+      url: "https://habr.com/ru/articles/942236/",
+      format: "A4",
+      theme: "light",
+    });
+    expect(pdf.length).toBeGreaterThan(20_000);
+    expect(pdf.subarray(0, 5).toString()).toBe("%PDF-");
+    expect(title.length).toBeGreaterThan(3);
+  }, 120_000);
+});

src/lib/clean-pdf/generate.ts

@@ -0,0 +1,99 @@
+import { isIP } from "node:net";
+import { chromium } from "playwright-core";
+import { JSDOM } from "jsdom";
+import { Defuddle } from "defuddle/node";
+import { assertPublicUrl, isPrivateAddress } from "@/lib/clean-pdf/ssrf";
+import { buildCleanHtml } from "@/lib/clean-pdf/template";
+
+export class EmptyContentError extends Error {}
+export class RenderError extends Error {}
+
+const GOTO_TIMEOUT_MS = 30_000;
+const SETTLE_TIMEOUT_MS = 10_000;
+const UA =
+  "Mozilla/5.0 (Macintosh; Intel Mac OS X 10_15_7) AppleWebKit/537.36 (KHTML, like Gecko) Chrome/126.0 Safari/537.36";
+
+function browserWsUrl(): string {
+  const base = process.env.BROWSER_WS_URL;
+  if (!base) throw new RenderError("BROWSER_WS_URL не задан");
+  const token = process.env.BROWSERLESS_TOKEN;
+  return token ? `${base}${base.includes("?") ? "&" : "?"}token=${token}` : base;
+}
+
+export async function generateCleanPdf(opts: {
+  url: string;
+  format: "A4" | "Letter";
+  theme: "light" | "dark";
+}): Promise<{ pdf: Buffer; title: string }> {
+  const target = await assertPublicUrl(opts.url);
+
+  const browser = await chromium.connectOverCDP(browserWsUrl()).catch((e) => {
+    throw new RenderError(`Браузер недоступен: ${e.message}`);
+  });
+
+  try {
+    const context = await browser.newContext({ userAgent: UA, viewport: { width: 1280, height: 800 } });
+    // Вторая линия SSRF-обороны: страница не может дёргать приватные адреса
+    // (литеральные IP и localhost; hostnames уже проверены до goto).
+    await context.route("**/*", (route) => {
+      try {
+        const u = new URL(route.request().url());
+        const host = u.hostname.replace(/^\[|\]$/g, "");
+        if (
+          (u.protocol !== "http:" && u.protocol !== "https:") ||
+          host === "localhost" || host.endsWith(".local") || host.endsWith(".internal") ||
+          (isIP(host) !== 0 && isPrivateAddress(host))
+        ) {
+          return route.abort();
+        }
+      } catch {
+        return route.abort();
+      }
+      return route.continue();
+    });
+
+    const page = await context.newPage();
+    await page.goto(target.href, { waitUntil: "domcontentloaded", timeout: GOTO_TIMEOUT_MS }).catch((e) => {
+      throw new RenderError(`Страница не открылась: ${e.message}`);
+    });
+    await page.waitForLoadState("networkidle", { timeout: SETTLE_TIMEOUT_MS }).catch(() => {});
+
+    const rawHtml = await page.content();
+    const pageTitle = await page.title().catch(() => "");
+
+    const dom = new JSDOM(rawHtml, { url: target.href });
+    const article = await Defuddle(dom.window.document, target.href);
+    // DefuddleResponse (node_modules/defuddle/dist/types.d.ts) типизирует
+    // content/title/author/site/domain/wordCount как обязательные (не optional) поля —
+    // сам объект тоже не nullable (Defuddle() не возвращает null/undefined).
+    // Отсутствие контента выражается пустой строкой/нулевым wordCount, не отсутствием поля.
+    if (!article.content || article.wordCount < 10) {
+      throw new EmptyContentError("Не удалось выделить содержимое страницы");
+    }
+
+    const title = article.title || pageTitle || target.hostname;
+    const cleanHtml = buildCleanHtml({
+      title,
+      author: article.author || undefined,
+      site: article.site || article.domain || undefined,
+      url: target.href,
+      contentHtml: article.content,
+      theme: opts.theme,
+    });
+
+    const pdfPage = await context.newPage();
+    await pdfPage.setContent(cleanHtml, { waitUntil: "networkidle", timeout: SETTLE_TIMEOUT_MS }).catch(() => {});
+    // page.pdf() в playwright-core не принимает опцию timeout (проверено по
+    // node_modules/playwright-core/types/types.d.ts) — брифовский вариант с
+    // timeout здесь не компилировался, поле убрано.
+    const pdf = await pdfPage.pdf({
+      format: opts.format,
+      printBackground: true,
+      margin: { top: "15mm", bottom: "18mm", left: "15mm", right: "15mm" },
+    });
+
+    return { pdf, title };
+  } finally {
+    await browser.close().catch(() => {});
+  }
+}