v4: link previews are read once, in one place, and no longer take an error page, a relative image or a mask icon for the page's — each provider fetched its page and scanned it with regular expressions of its own, the generic one some fifteen times, and Bandcamp and SoundCloud read only OG tags. fetchPage (remote/fetch.ts) now fetches every page, follows redirects to the address it was served from, and refuses an error status, so a 404 or a bot challenge is unreachable rather than a preview titled "Just a moment...", and a refresh no longer overwrites good metadata with it. parsePage (remote/html.ts) reads it in one linear pass with a real attribute reader: unquoted values, a > inside quotes, og: tags under name as well as property, and nothing from comments or scripts. Every URL a page names is resolved against where it was served from, so a relative og:image works; entities are decoded in one pass, &eacute; and &rsquo; included, and one that names no character no longer fails the preview (bandcamp-tralbum.ts shares the decoder). The mask icon is no longer the favicon, JSON-LD prefers the page's node over the site's, tracking pixels and lazy placeholders aren't thumbnails, an og:url with a slug keeps the OG tags, and a <title> loses its site suffix. genericPreview is the base of the Bandcamp, SoundCloud and YouTube channel previews; SoundCloud takes www., m. and on.soundcloud.com short links, embedding the page they lead to, and Bandcamp keeps only its own player. The service tidies every preview: text on one line, titles and descriptions capped, only http(s) images and players. RichContent.type is now RichContentType, and the unused videoId is gone.

Co-Authored-By: Claude Opus 5.5 <noreply@anthropic.com>

api/test/remote/providers/generic.test.ts

@@ -1,5 +1,5 @@
 import { html, stubNetwork } from "../../helpers.ts";
-import { assertEquals } from "@std/assert";
+import { assert, assertEquals } from "@std/assert";
 import { fetchRichContent } from "../../../services/rich-content-service.ts";
 
 const BASE = "https://example.com/articles/1";
@@ -51,3 +51,67 @@ Deno.test("generic provider: non-HTML responses carry just the URL", async () =>
   );
   assertEquals(await fetchRichContent(BASE), { type: "generic", url: BASE });
 });
+
+Deno.test("generic provider: a canonical og:url with a slug keeps the OG tags", async () => {
+  using _ = stubNetwork(() =>
+    html(`
+      <meta property="og:url" content="https://example.com/q/123/how-to-x">
+      <meta property="og:title" content="How to X">
+      <meta property="og:image" content="https://example.com/x.jpg">
+      <title>How to X - Example</title>`)
+  );
+  const content = await fetchRichContent("https://example.com/q/123");
+  assertEquals(content?.title, "How to X");
+  assertEquals(content?.thumbnailUrl, "https://example.com/x.jpg");
+});
+
+Deno.test("generic provider: relative URLs resolve against the page after redirects", async () => {
+  using _ = stubNetwork((url) =>
+    url.hostname === "old.example"
+      ? new Response(null, {
+        status: 301,
+        headers: { location: "https://new.example/b/page" },
+      })
+      : html(`<meta property="og:image" content="/og.png">
+              <meta name="twitter:image" content="https://new.example/tw.png">`)
+  );
+  const content = await fetchRichContent("https://old.example/a");
+  assertEquals(content?.url, "https://old.example/a");
+  assertEquals(content?.thumbnailUrl, "https://new.example/og.png");
+  assertEquals(content?.faviconUrl, "https://new.example/favicon.ico");
+});
+
+Deno.test("generic provider: an og:image that isn't http(s) falls through", async () => {
+  using _ = stubNetwork(() =>
+    html(`<meta property="og:image" content="javascript:alert(1)">
+          <meta name="twitter:image" content="//cdn.example/tw.png">`)
+  );
+  assertEquals(
+    (await fetchRichContent(BASE))?.thumbnailUrl,
+    "https://cdn.example/tw.png",
+  );
+});
+
+Deno.test("generic provider: a <title> loses its site suffix", async () => {
+  using _ = stubNetwork(() =>
+    html(`<meta property="og:site_name" content="Le Monde">
+          <title>Un article &eacute;crit — Le Monde</title>`)
+  );
+  const content = await fetchRichContent(BASE);
+  assertEquals(content?.title, "Un article écrit");
+  assertEquals(content?.siteName, "Le Monde");
+});
+
+Deno.test("generic provider: text on one line, and of bounded length", async () => {
+  using _ = stubNetwork(() =>
+    html(`<title>
+            A title
+            on two lines
+          </title>
+          <meta name="description" content="${"word ".repeat(400)}">`)
+  );
+  const content = await fetchRichContent(BASE);
+  assertEquals(content?.title, "A title on two lines");
+  assertEquals([...content!.description!].length, 1000);
+  assert(content!.description!.endsWith("word…"));
+});