9web: multiplexer, HTTP view of the tree, live streams, richer page

One upstream 9P connection now serves any number of browser WebSocket
sessions and, with --serve, plain 9P clients over TCP or Unix (a 9pserve-
style frame remux: tags and fids remapped, Tflush forwarded, reconnect on
upstream loss). /fs/<path> maps HTTP onto the tree: GET file or directory
(JSON or HTML), Range, HEAD with 9P headers, PUT (create, truncate, append,
trailing slash makes a directory), DELETE, and ?follow=1 or text/event-stream
turning a blocking read into server-sent events with Tflush on disconnect.
The page gains a lazy tree, stat panel, create, rename, delete, upload and
follow mode. --probe embeds 9proc for self-introspection. New mux-test and
http-fs-test steps; e2e still passes.

Co-Authored-By: Claude Fable 5.1 <[email protected]>

1 files changed, 131 insertions, 0 deletions

diff --git a/test/web/http_fs.mjs b/test/web/http_fs.mjs
new file mode 100644
index 0000000..8ac4961
--- /dev/null
+++ b/test/web/http_fs.mjs
@@ -0,0 +1,131 @@
+// HTTP /fs mapping tests: spawn 9proc-demo as the upstream and 9web as the
+// gateway, then exercise GET (file/dir/Range/SSE), HEAD, PUT (create/truncate/
+// append), DELETE, mkdir, 404 mapping, and concurrent fan-out over the one
+// shared upstream. No npm packages; Node 22+ builtins only.
+import assert from 'node:assert/strict';
+import { spawn } from 'node:child_process';
+import { once } from 'node:events';
+import path from 'node:path';
+import os from 'node:os';
+import fs from 'node:fs/promises';
+
+const [demoBin, webBin] = process.argv.slice(2).map(p => path.resolve(p));
+if (!webBin) throw new Error('usage: node test/web/http_fs.mjs 9proc-demo 9web');
+
+const children = [];
+const delay = ms => new Promise(r => setTimeout(r, ms));
+function start(cmd, args) {
+  const c = spawn(cmd, args, { stdio: ['ignore', 'pipe', 'pipe'] });
+  c.out = ''; c.err = '';
+  c.stdout.on('data', b => { c.out += b; });
+  c.stderr.on('data', b => { c.err += b; });
+  c.on('error', e => { c.err += e.message; });
+  children.push(c);
+  return c;
+}
+async function wait(check, msg, timeout = 8000) {
+  const end = Date.now() + timeout;
+  while (Date.now() < end) { try { const r = await check(); if (r) return r; } catch {} await delay(40); }
+  throw new Error('timeout: ' + msg);
+}
+
+let sock, url;
+try {
+  sock = path.join(await fs.mkdtemp(path.join(os.tmpdir(), '9web-')), 'up');
+  const demo = start(demoBin, ['--unix', sock]);
+  await wait(() => demo.err.includes('listening') || demo.out.includes('listening'), '9proc-demo ready');
+  const web = start(webBin, ['--listen', '127.0.0.1:0', '--upstream', `unix:${sock}`, '--timeout-ms', '0']);
+  const m = await wait(() => web.err.match(/9web (http:\/\/127\.0\.0\.1:\d+)/), '9web ready');
+  url = m[1];
+
+  // GET directory -> JSON with real stats.
+  const root = await (await fetch(`${url}/fs/`)).json();
+  const names = root.map(e => e.name);
+  assert.ok(names.includes('README') && names.includes('runtime') && names.includes('scratch'), 'root listing');
+  const readme = root.find(e => e.name === 'README');
+  assert.equal(readme.dir, false);
+  assert.ok(readme.qid && typeof readme.qid.path === 'number' || typeof readme.qid.path === 'bigint');
+
+  // GET directory as HTML.
+  const htmlRes = await fetch(`${url}/fs/`, { headers: { accept: 'text/html' } });
+  assert.match(htmlRes.headers.get('content-type'), /text\/html/);
+  assert.match(await htmlRes.text(), /<li>README<\/li>/);
+
+  // GET file.
+  const rd = await fetch(`${url}/fs/README`);
+  assert.equal(rd.status, 200);
+  assert.match(rd.headers.get('content-type'), /text\/plain/);
+  assert.match(await rd.text(), /9P2000/);
+
+  // GET a dynamic (length-0) file streams its content.
+  const now = (await (await fetch(`${url}/fs/runtime/fn/now`)).text()).trim();
+  assert.match(now, /^\d+$/, 'runtime/fn/now');
+
+  // HEAD.
+  const hd = await fetch(`${url}/fs/README`, { method: 'HEAD' });
+  assert.equal(hd.status, 200);
+  assert.ok(Number(hd.headers.get('content-length')) > 0);
+  assert.ok(hd.headers.get('x-9p-qid'));
+
+  // Range.
+  const rg = await fetch(`${url}/fs/README`, { headers: { range: 'bytes=0-4' } });
+  assert.equal(rg.status, 206);
+  assert.equal((await rg.text()).length, 5);
+
+  // 404 mapping.
+  assert.equal((await fetch(`${url}/fs/nope/missing`)).status, 404);
+
+  // PUT create + GET + truncate + append + DELETE round trip on /scratch.
+  let put = await fetch(`${url}/fs/scratch/rt.txt`, { method: 'PUT', body: 'hello mux' });
+  assert.equal(put.status, 201);
+  assert.equal(await (await fetch(`${url}/fs/scratch/rt.txt`)).text(), 'hello mux');
+  put = await fetch(`${url}/fs/scratch/rt.txt`, { method: 'PUT', body: 'AA' });
+  assert.equal(put.status, 200); // existed -> truncate
+  assert.equal(await (await fetch(`${url}/fs/scratch/rt.txt`)).text(), 'AA');
+  await fetch(`${url}/fs/scratch/rt.txt?append=1`, { method: 'PUT', body: 'BB' });
+  assert.equal(await (await fetch(`${url}/fs/scratch/rt.txt`)).text(), 'AABB');
+  assert.equal((await fetch(`${url}/fs/scratch/rt.txt`, { method: 'DELETE' })).status, 204);
+  assert.equal((await fetch(`${url}/fs/scratch/rt.txt`)).status, 404);
+
+  // mkdir via trailing slash.
+  assert.equal((await fetch(`${url}/fs/scratch/sub/`, { method: 'PUT' })).status, 201);
+  assert.equal((await fetch(`${url}/fs/scratch/sub`)).status, 200);
+
+  // Larger body: multi-frame streamed PUT then GET byte-exact.
+  const big = Buffer.alloc(150000);
+  for (let i = 0; i < big.length; i++) big[i] = (i * 17) % 251;
+  assert.equal((await fetch(`${url}/fs/scratch/big.bin`, { method: 'PUT', body: big })).status, 201);
+  const back = Buffer.from(await (await fetch(`${url}/fs/scratch/big.bin`)).arrayBuffer());
+  assert.ok(back.equals(big), 'byte-exact large round trip');
+
+  // SSE: follow a file streams its content as data: events.
+  const ac = new AbortController();
+  const sse = await fetch(`${url}/fs/README?follow=1`, { signal: ac.signal });
+  assert.match(sse.headers.get('content-type'), /text\/event-stream/);
+  const reader = sse.body.getReader();
+  let text = '';
+  while (text.length < 40) {
+    const { value, done } = await reader.read();
+    if (done) break;
+    text += Buffer.from(value).toString();
+  }
+  ac.abort();
+  assert.match(text, /data: /, 'SSE data event');
+
+  // Fan-out: many concurrent requests share the one upstream (16 tags).
+  const results = await Promise.all(Array.from({ length: 16 }, () =>
+    fetch(`${url}/fs/runtime/fn/now`).then(r => r.status).catch(e => 'ERR:' + e.message)));
+  const bad = results.filter(s => s !== 200);
+  assert.ok(bad.length === 0, 'concurrent fan-out, non-200: ' + JSON.stringify(bad));
+
+  console.log('http_fs: all checks passed');
+} catch (e) {
+  console.error(e.stack || e);
+  for (const c of children) if (c.err) console.error(c.spawnargs.join(' '), '\n', c.err.slice(-2000));
+  process.exitCode = 1;
+} finally {
+  for (const c of children) if (c.exitCode === null) c.kill('SIGTERM');
+  await delay(200);
+  for (const c of children) if (c.exitCode === null) c.kill('SIGKILL');
+  if (sock) await fs.rm(path.dirname(sock), { recursive: true, force: true }).catch(() => {});
+}