1 files changed, 151 insertions, 0 deletions
diff --git a/packages/meshbay-hub/tests/harness/lazy_failure_probe.py b/packages/meshbay-hub/tests/harness/lazy_failure_probe.py
new file mode 100644
index 0000000..357529a
--- /dev/null
+++ b/packages/meshbay-hub/tests/harness/lazy_failure_probe.py
@@ -0,0 +1,151 @@
+#!/usr/bin/env python3
+"""
+What `lazy()` shows when the module it asks for answers 404.
+
+The shape found live: a tab opened before a hub deploy asks for its not-yet-
+loaded modules under the previous `/a/<hash>/` prefix, which the new hub no
+longer serves. Every lazily loaded view — Search, Videos, Music, Photos, the
+video player — sat on its spinner for good, with an empty console. This
+renders the shipped `lazy.js` against a module that does not exist, and one
+that does, and reads back what is on the page.
+
+    lazy_failure_probe.py
+"""
+
+import http.server
+import json
+import socketserver
+import subprocess
+import sys
+import tempfile
+import threading
+import time
+from pathlib import Path
+
+STATIC = Path(__file__).resolve().parents[2] / "src" / "meshbay_hub" / "static"
+PORT = 8763
+RECORDS = []
+socketserver.TCPServer.allow_reuse_address = True
+
+FRAME = r"""<!doctype html><html><head><meta charset=utf-8>
+<link rel="stylesheet" href="/style.css"></head><body>
+<div id="plain"></div><div id="framed"></div><div id="fine"></div>
+<script type="module">
+import { html, render } from '/vendor/htm-preact.js';
+import { initLocale } from '/i18n.js';
+import { lazy } from '/lazy.js';
+
+const sleep = (ms) => new Promise((r) => setTimeout(r, ms));
+const errors = [];
+const origError = console.error;
+console.error = (...a) => { errors.push(a.map(String).join(' ')); origError(...a); };
+
+const read = (id) => {
+  const root = document.getElementById(id);
+  return {
+    spinner: !!root.querySelector('.spinner'),
+    notice: (root.querySelector('.lazy-failed p') || {}).textContent || null,
+    buttons: [...root.querySelectorAll('.lazy-failed button')].map((b) => b.textContent.trim()),
+    overlay: !!root.querySelector('.video-player-overlay .lazy-failed'),
+    text: root.textContent.trim(),
+  };
+};
+
+(async () => {
+  try {
+    await initLocale();
+    // The stale tab's request: a module under a prefix nobody serves.
+    const Gone = lazy(() => import('/a/0000000000/gone.js'), 'Gone');
+    const frame = (c) => html`<div class="video-overlay video-player-overlay">${c}</div>`;
+    const GoneOverlay = lazy(() => import('/a/0000000000/player.js'), 'Player',
+      frame(html`<p class="page-message"><span class="spinner"></span></p>`), frame);
+    // A module that exists still renders as itself.
+    const Fine = lazy(() => import('/icon.js'), 'Icon');
+
+    let closed = 0;
+    render(html`<${Gone} />`, document.getElementById('plain'));
+    render(html`<${GoneOverlay} onClose=${() => { closed += 1; }} />`,
+      document.getElementById('framed'));
+    render(html`<${Fine} name="close" />`, document.getElementById('fine'));
+    await sleep(1500);
+
+    const out = { plain: read('plain'), framed: read('framed'), errors,
+                  fine: !!document.querySelector('#fine svg, #fine .icon') };
+    const btns = document.querySelectorAll('#framed .lazy-failed button');
+    if (btns[1]) btns[1].click();
+    out.closed = closed;
+    parent.postMessage(out, '*');
+  } catch (err) {
+    parent.postMessage({ error: String((err && err.stack) || err) }, '*');
+  }
+})();
+</script></body></html>"""
+
+PAGE = r"""<!doctype html><html><head><meta charset=utf-8></head>
+<body style="margin:0"><iframe src="/case" style="width:900px;height:700px;border:0"></iframe>
+<script>
+addEventListener('message', (e) => fetch('/log', { method: 'POST', body: JSON.stringify(e.data) }));
+</script></body></html>"""
+
+
+class H(http.server.BaseHTTPRequestHandler):
+    def log_message(self, *a):
+        pass
+
+    def do_POST(self):
+        length = int(self.headers.get("Content-Length") or 0)
+        if self.path == "/log":
+            RECORDS.append(json.loads(self.rfile.read(length).decode()))
+        else:
+            self.rfile.read(length)
+        self.send_response(204)
+        self.end_headers()
+
+    def _send(self, body: bytes, ctype: str) -> None:
+        self.send_response(200)
+        self.send_header("Content-Type", ctype)
+        self.send_header("Content-Length", str(len(body)))
+        self.end_headers()
+        self.wfile.write(body)
+
+    def do_GET(self):
+        path = self.path.split("?")[0]
+        if path == "/":
+            self._send(PAGE.encode(), "text/html; charset=utf-8")
+        elif path == "/case":
+            self._send(FRAME.encode(), "text/html; charset=utf-8")
+        else:
+            asset = (STATIC / path.lstrip("/")).resolve()
+            if not str(asset).startswith(str(STATIC)) or not asset.is_file():
+                self.send_response(404)
+                self.end_headers()
+                return
+            self._send(asset.read_bytes(),
+                       "text/css" if asset.suffix == ".css"
+                       else "text/javascript" if asset.suffix == ".js"
+                       else "application/octet-stream")
+
+
+def main() -> int:
+    with socketserver.TCPServer(("127.0.0.1", PORT), H) as srv:
+        threading.Thread(target=srv.serve_forever, daemon=True).start()
+        with tempfile.TemporaryDirectory(ignore_cleanup_errors=True) as profile:
+            proc = subprocess.Popen(
+                ["google-chrome", "--headless=new", "--disable-gpu", "--no-sandbox",
+                 f"--user-data-dir={profile}", "--window-size=900,700",
+                 f"http://127.0.0.1:{PORT}/"],
+                stdout=subprocess.DEVNULL, stderr=subprocess.DEVNULL)
+            deadline = time.time() + 60
+            while not RECORDS and time.time() < deadline:
+                time.sleep(0.2)
+            proc.terminate()
+            proc.wait(timeout=20)
+    if not RECORDS:
+        print("the page never reported", file=sys.stderr)
+        return 1
+    print(json.dumps(RECORDS[0]))
+    return 0
+
+
+if __name__ == "__main__":
+    raise SystemExit(main())