1 files changed, 126 insertions, 0 deletions
diff --git a/test/selfmount.py b/test/selfmount.py
new file mode 100644
index 00000000..cc889a93
--- /dev/null
+++ b/test/selfmount.py
@@ -0,0 +1,126 @@
+#!/usr/bin/env python3
+"""A session that opens, reads and saves its own 9P tree through a mount.
+
+The editor runs under `9ns --mntgen`, so /mnt/9p/pardes/<name> inside its
+namespace is its own tree, and is driven over its socket from outside. This
+used to hang the editor outright: the realpath, the stat and the read went
+out through the mount and came back as 9P requests only the editor's loop
+could answer, while that loop was blocked making them. Now the connection's
+task answers them while the editor waits (pardes.turn).
+
+Needs 9ns (cloud9) on PATH or in ~/.local/bin, and a runtime directory; it
+skips, loudly, without them.
+"""
+import fcntl
+import os
+from pathlib import Path
+import pty
+import shutil
+import signal
+import struct
+import sys
+import termios
+import time
+
+sys.path.insert(0, str(Path(__file__).resolve().parent))
+from ninep import Client
+
+
+def run(binary):
+    ns = shutil.which('9ns') or str(Path.home() / '.local/bin/9ns')
+    runtime = os.environ.get('XDG_RUNTIME_DIR')
+    if not os.path.exists(ns) or not runtime:
+        print('selfmount: skipped (needs 9ns and XDG_RUNTIME_DIR)')
+        return 0
+    name = 'selfmount%d' % os.getpid()
+    sock = f'{runtime}/pardes-9p-{name}.sock'
+    fixture = Path(f'/tmp/{name}.txt')
+    fixture.write_bytes(b'initial\n')
+    env = {k: v for k, v in os.environ.items() if not k.startswith('PARDES_')}
+    env.update(PARDES_NOTIME='1', TERM='xterm-256color', PARDES_DUMP=f'/tmp/{name}.dump.zon')
+    for language in ['RS', 'C', 'GO', 'TS', 'PY']:
+        env['PARDES_LSP_' + language] = ''
+    pid, master = pty.fork()
+    if pid == 0:
+        os.execve(ns, ['9ns', '--mntgen', '--', binary, '--tty', '--9p=' + name, str(fixture)], env)
+    fcntl.ioctl(master, termios.TIOCSWINSZ, struct.pack('HHHH', 30, 100, 0, 0))
+    os.set_blocking(master, False)
+    tail = bytearray()
+
+    def drain():
+        try:
+            while True:
+                chunk = os.read(master, 65536)
+                if not chunk:
+                    return
+                tail.extend(chunk[-2000:])
+        except OSError:
+            pass
+
+    failures = []
+
+    def check(condition, what):
+        print(('ok   ' if condition else 'FAIL ') + what)
+        if not condition:
+            failures.append(what)
+
+    try:
+        deadline = time.monotonic() + 15
+        while not os.path.exists(sock):
+            drain()
+            if time.monotonic() > deadline:
+                raise TimeoutError('socket never appeared: ' + tail.decode(errors='replace')[-400:])
+            time.sleep(.02)
+        time.sleep(.3)
+        mount = f'/mnt/9p/pardes/{name}'
+        with Client(sock) as client:
+            index = client.read('/index').decode()
+            rows = [row.split(maxsplit=3) for row in index.splitlines()]
+            first = rows[0][0]
+            # A Look at the tree's own index: realpath, stat and read all go
+            # out through 9ns and back in, and the write returns when the
+            # pane is open.
+            started = time.monotonic()
+            client.write('/look', (mount + '/index\n').encode())
+            took = time.monotonic() - started
+            check(took < 5, f'look at the mounted index returned ({took:.2f}s)')
+            rows = [row.split(maxsplit=3) for row in client.read('/index').decode().splitlines()]
+            opened = [row for row in rows if len(row) == 4 and row[3] == mount + '/index']
+            check(len(opened) == 1, 'a pane opened on the mounted index')
+            if opened:
+                body = client.read(f'/pane/{opened[0][0]}/body').decode()
+                check(body.startswith(index.splitlines()[0]), 'its body is the index as served')
+            # A Look at pane 1's body through the mount, an edit of the copy,
+            # and a Save: the save writes back through the mount into pane 1,
+            # and the exec returns once it has.
+            client.write('/look', f'{mount}/pane/{first}/body\n'.encode())
+            rows = [row.split(maxsplit=3) for row in client.read('/index').decode().splitlines()]
+            mirror = [row for row in rows if len(row) == 4 and row[3] == f'{mount}/pane/{first}/body']
+            check(len(mirror) == 1, 'a pane opened on the mounted body')
+            if mirror:
+                pane = mirror[0][0]
+                client.write(f'/pane/{pane}/addr', b'#0,#0')
+                client.write(f'/pane/{pane}/data', b'HELLO ')
+                client.write(f'/pane/{pane}/exec', b'Save\n')
+                check(client.read(f'/pane/{first}/body') == b'HELLO initial\n', f'Save wrote back through the mount into pane {first}')
+                text = ''.join(cell[0] for cell in client.screen()['cells'])
+                check('saved ' + mount in text, 'the editor reported the save')
+            client.write('/exec', b'Msg still here\n')
+            text = ''.join(cell[0] for cell in client.screen()['cells'])
+            check('still here' in text, 'the editor answers after all of that')
+    finally:
+        os.kill(pid, signal.SIGTERM)
+        time.sleep(.2)
+        try:
+            os.kill(pid, signal.SIGKILL)
+        except ProcessLookupError:
+            pass
+        os.waitpid(pid, 0)
+        for path in (fixture, Path(f'/tmp/{name}.dump.zon')):
+            path.unlink(missing_ok=True)
+    print('selfmount: ' + ('ok' if not failures else f'{len(failures)} failed'))
+    return 0 if not failures else 1
+
+
+if __name__ == '__main__':
+    sys.exit(run(str(Path(sys.argv[1]).resolve())))