A root commands file lists every builtin, its argument and which ctl takes it

A script could learn the builtin words only from source or the Help
window. /commands is generated from the registry: one line per builtin,
Word or Word arg, then root or pane for the ctl that takes it, so it is
always this build's own list.

Co-Authored-By: Claude Opus 5.5 <[email protected]>

1 files changed, 5 insertions, 1 deletions

diff --git a/test/fs.py b/test/fs.py
index 82d7cf0b..bafe665c 100644
--- a/test/fs.py
+++ b/test/fs.py
@@ -261,6 +261,10 @@ def discovery(binary, embedded=False):
                     raise AssertionError(f'{path} took {line!r}')
                 except OSError as refused:
                     assert why in str(refused), refused
+            commands = client.read('/commands').decode().splitlines()
+            assert 'Newcol root' in commands and 'Save arg pane' in commands, commands
+            assert all(row.split()[-1] in ('root', 'pane') for row in commands), commands
+            assert client.stat('/commands')['length'] == len('\n'.join(commands)) + 1
             client.write(f'/pane/{first}/ctl', b'Msg said through ctl\n')
             assert 'said through ctl' in ''.join(cell[0] for cell in client.screen()['cells'])
             assert set(client.list('/pane')) == {'new', str(fixture), str(first), str(second)}
@@ -333,7 +337,7 @@ def discovery(binary, embedded=False):
                 assert client.read('/src/pardes.zig').startswith(b'const std')
                 assert client.stat('/src/pardes.zig')['mode'] == 0o444
                 assert b'pub const Pardes' in client.read(f'/pane/{look(client, "/virtual/src/pardes.zig")}/body')
-    print('9P discovery: listing/stat/find are inert; new, remove, look, exec, name, sel, log, ctl lock, focus and the ctl split behave')
+    print('9P discovery: listing/stat/find are inert; new, remove, look, exec, name, sel, log, ctl lock, focus, the ctl split and commands behave')
 
 
 def run_file(binary):