fix(server): html_preview no longer splits an emoji in a long console line

apps/server/src/htmlRender/HtmlRender.test.ts

@@ -350,16 +350,24 @@ fs.createReadStream(null, { fd: 3 }).on("end", quit).on("data", (chunk) => {
   for (const { id, method, sessionId } of messages.map((raw) => JSON.parse(raw))) {
     if (method === "Browser.close") quit();
     reply({ id, sessionId, result: results[method] ?? {} });
-    if (method === "Page.navigate") reply({ sessionId, method: "Page.loadEventFired", params: {} });
+    if (method === "Page.navigate") {
+      const value = "x" + "\u{1F600}".repeat(300);
+      const params = { type: "log", args: [{ type: "string", value }] };
+      reply({ sessionId, method: "Runtime.consoleAPICalled", params });
+      reply({ sessionId, method: "Page.loadEventFired", params: {} });
+    }
   }
 });
 `,
             { mode: 0o755 },
           );
 
-          yield* HtmlRender.HtmlRender.use((htmlRender) =>
+          const preview = yield* HtmlRender.HtmlRender.use((htmlRender) =>
             htmlRender.preview({ html: "<p>x</p>" }),
           ).pipe(Effect.provide(layerHtmlRender(executable)));
+          const logged = preview.consoleMessages[0]?.text ?? "";
+          expect(logged.isWellFormed()).toBe(true);
+          expect(logged).toHaveLength(500);
 
           const exitedBy = yield* fileSystem.readFileString(exitRecord).pipe(Effect.option);
           expect(Option.getOrElse(exitedBy, () => "killed by a signal")).toBe("asked to close");

apps/server/src/htmlRender/headlessChrome.ts

@@ -316,10 +316,13 @@ const launchBrowser = Effect.fnUntraced(function* (input: {
       return yield* Effect.void;
     }
     const text = consoleMessage.text.replaceAll(PAGE_URL, PAGE_NAME);
+    // Half an emoji serializes to a lone surrogate escape, which provider JSON parsers reject.
+    const last = text.charCodeAt(MAX_CONSOLE_TEXT_CHARS - 1);
+    const end =
+      last >= 0xd800 && last <= 0xdbff ? MAX_CONSOLE_TEXT_CHARS - 1 : MAX_CONSOLE_TEXT_CHARS;
     page.consoleMessages.push({
       level: consoleMessage.level,
-      text:
-        text.length > MAX_CONSOLE_TEXT_CHARS ? `${text.slice(0, MAX_CONSOLE_TEXT_CHARS)}…` : text,
+      text: text.length > MAX_CONSOLE_TEXT_CHARS ? `${text.slice(0, end)}…` : text,
     });
     return yield* Effect.void;
   });