fix(webui): sp1 second review round, a read or file save in flight at a switch keeps nothing (#1873, lane sp1)

The second review found two paths the first fix round left open.

- The project-file save captures orgEpoch before its POST. When a switch
  happened meanwhile, it neither paints nor announces the old file's
  outcome on the new organization's page. An opaqueredirect still signs out.
- A live read (reader, get.api), the palette's inbox and tasks reads and
  the board poll keep their answer in `last` only while the organization
  they were sent for is still open. A later cached render on the new
  organization no longer draws the old one's rows.

single-pane test 11 holds acme's file save across a switch to beta and
asserts nothing is announced: red on the previous bus.js ("Saved as commit
cccccccccccc."), green now. The kept-read guard has no browser test.

packages/webui/src/public/bus.js

@@ -75,13 +75,17 @@
     window.MosaicIcons.succeeded();
     return body;
   }
+  // #1873 SP1: bumped by each in-place organization switch. A write, or a read that keeps its answer,
+  // captures it before its await and drops the answer when it changed, so nothing the old organization
+  // answered lands on the new page or in its kept answers.
+  let orgEpoch = 0;
   // A reader for one render. `live` asks the server; otherwise only kept answers are used.
   function reader(live) {
     const used = [];
     const get = async (verb, subject) => {
       const k = subject === undefined ? verb : `${verb}:${subject}`;
       let r;
-      if (live) { r = await fetchRead(verb, subject); last.set(k, r); }
+      if (live) { const epoch = orgEpoch; r = await fetchRead(verb, subject); if (epoch === orgEpoch) last.set(k, r); }
       else if (!(r = last.get(k))) throw new ReadError('not-read', 'not read before');
       used.push(r.at);
       if (verb === 'messages') { messageCount = r.unread; return r; }
@@ -90,7 +94,7 @@
     get.api = async path => {
       const k = `api:${path}`;
       let r;
-      if (live) { r = await fetchApi(path); last.set(k, r); }
+      if (live) { const epoch = orgEpoch; r = await fetchApi(path); if (epoch === orgEpoch) last.set(k, r); }
       else if (!(r = last.get(k))) throw new ReadError('not-read', 'not read before');
       used.push(r.at);
       return r;
@@ -345,9 +349,6 @@
   let configRead = Promise.resolve();
   // #1873 SP1: the config read an organization switch started, until the next render has waited for it.
   let switchRead = null;
-  // #1873 SP1: bumped by each in-place organization switch. A write captures it before its await and
-  // drops its answer when it changed, so nothing the old organization answered lands on the new page.
-  let orgEpoch = 0;
   let canSend = false, canMessage = false, chatSend = false, sendRoles = null, sending = false, receipt = null, replies = [];
   const REPLIES = 50; // the broker's cap
   function repliesHtml() {
@@ -1539,6 +1540,7 @@
     if (!s || !saveable(s)) return;
     const sent = { project: s.project, path: s.path, base: s.commit, content: s.text }, unknown = 'Outcome unknown: the save may have gone through. Copy your text, then reload the file to check before saving again. Draft kept.';
     s.saving = true; s.status = '';
+    const epoch = orgEpoch;
     let res = null, body = null;
     try {
       paintDoc();
@@ -1550,6 +1552,9 @@
       } else if (body?.sent === false) s.status = `${typeof body.message === 'string' && body.message ? body.message : 'Not saved.'} Draft kept.`;
       else s.status = unknown;
     } finally { s.saving = false; } // a throw above must not leave Save off and Reload refused
+    // #1873 SP1: a switch while this was in flight cleared the drafts; the old file's outcome is not
+    // painted or announced on the new organization's page.
+    if (epoch !== orgEpoch) { if (res?.type === 'opaqueredirect') signOut(); return; }
     paintDoc();
     announce(s.status);
     if (res?.type === 'opaqueredirect') signOut();
@@ -1756,12 +1761,15 @@
       // The board page keeps its own title; the Inbox count still follows the bus.
       if (shown !== null) { shown = null; unmountEditor(); $('bus-view').innerHTML = ''; document.title = 'Dashboard · Mosaic Console'; if (navigated) $('main').focus(); }
       // The held roles (row 95) are read with it. A refusal of either forgets both, as on the bus pages.
+      const epoch = orgEpoch;
       const [inbox, agents, messages, tasks, queue, business, projects] = await Promise.allSettled([
         fetchRead('inbox'), fetchRead('agents'), fetchRead('messages'), fetchRead('tasks'), fetchApi('queue'), fetchApi('business'),
         fetch('/api/chat/projects', { cache: 'no-store', redirect: 'manual' }).then(async r => { if (r.type === 'opaqueredirect') { signOut(); throw signedOut(); } const body = await r.json(); if (signInRequired(r, body)) { signOutSso(); throw signedOut(); } if (!r.ok || !Array.isArray(body.rows)) throw new ReadError(body?.error, body?.message, r.status); return body; })
       ]);
       const failed = [inbox, agents, messages, tasks].filter(s => s.status === 'rejected').map(s => s.reason);
       if (failed.some(err => err.code === 'signed-out')) return;
+      // #1873 SP1: an answer read for an organization that is no longer open is not kept.
+      if (epoch !== orgEpoch) return;
       if (inbox.status === 'fulfilled') last.set('inbox', inbox.value);
       if (agents.status === 'fulfilled') last.set('agents', agents.value);
       if (messages.status === 'fulfilled') last.set('messages', messages.value);
@@ -1902,7 +1910,9 @@
     if (d.open) return;
     pkBack = document.activeElement; pkAt = 0; $('cmdk-input').value = '';
     pkItems(); pkFill(); d.showModal(); $('cmdk-input').focus();
-    Promise.allSettled(['inbox', 'tasks'].map(async v => last.set(v, await fetchRead(v)))).then(rs => {
+    const epoch = orgEpoch;
+    Promise.allSettled(['inbox', 'tasks'].map(async v => { const r = await fetchRead(v); if (epoch === orgEpoch) last.set(v, r); })).then(rs => {
+      if (epoch !== orgEpoch) return;
       if (rs.some(r => r.status === 'rejected' && refusal(r.reason))) { forget(); sections(routeOf().split('?')[0]); }
       if (d.open) { pkItems(); pkFill(); }
     });

packages/webui/tests/single-pane-browser.test.mjs

@@ -285,3 +285,28 @@ test('a restart started on one organization finishes on that organization after
   // beta's page draws nothing of acme's chain.
   assert.equal(await b.evaluate('!!document.querySelector("[data-agent-restart-status=coder]")'), false);
 });
+
+test('a file save still in flight at a switch: its outcome is not announced on the next organization', async t => {
+  const json = 'new Response(JSON.stringify(x), { status: 200, headers: { "content-type": "application/json" } })';
+  // acme's file reads are stubbed; its save POST is held until the test releases it, then answers with a commit.
+  const init = `window.__posts = []; const original = window.fetch;
+    window.fetch = async (url, options = {}) => { const s = String(url); let x;
+      if (/^\\/api\\/orgs\\/[^/]+\\/config$/.test(s)) { const r = await original(url, options), body = await r.json(); x = { ...body, send: true, edit: true }; return ${json}; }
+      if (s.startsWith('/api/orgs/acme/project-file?')) { x = { path: 'docs/a.md', commit: 'a'.repeat(40), content: '# A\\n', at: new Date().toISOString() }; return ${json}; }
+      if (options.method === 'POST' && s === '/api/orgs/acme/project-file') { __posts.push(JSON.parse(options.body)); await new Promise(r => { window.__release = r; });
+        x = { path: 'docs/a.md', commit: 'c'.repeat(40) }; return ${json}; }
+      return original(url, options); };`;
+  const { b, wait } = await setup(t, { path: `/#/orgs/acme/docs/site/${encodeURIComponent('docs/a.md')}`, init });
+  await wait('document.querySelector("#doc-form")');
+  if (!await b.evaluate('!!document.querySelector("#doc-text")')) await b.evaluate('document.querySelector("#doc-mode-source").click(), true');
+  await wait('document.querySelector("#doc-text")?.value === "# A\\n"');
+  await b.evaluate('(() => { const a = document.querySelector("#doc-text"); a.value = "# A\\n\\nmore\\n"; a.dispatchEvent(new Event("input", { bubbles: true })); document.querySelector("#doc-form").requestSubmit(); })()');
+  await wait('typeof window.__release === "function"');
+  assert.equal(await b.evaluate('window.__posts[0]?.base'), 'a'.repeat(40));
+  await b.evaluate('location.hash = "#/orgs/beta/organization"');
+  await wait('location.hash === "#/orgs/beta/organization" && document.querySelector("[data-org-dashboard] h1")?.textContent === "Beta Works"');
+  await b.evaluate('window.__release()');
+  await new Promise(r => setTimeout(r, 700));
+  assert.equal(await b.evaluate('location.hash'), '#/orgs/beta/organization');
+  assert.doesNotMatch(await b.evaluate('document.getElementById("announce")?.textContent ?? ""'), /Saved as commit|Draft kept/);
+});