view tests/test-lfs-pointer.py @ 38162:bdf344aea0ee

extensions: peek command table of disabled extensions without importing

With chg where demandimport disabled, and if disk cache not warm, it took
more than 5 seconds to get "unknown command" error when you typo a command
name. This is horrible UX.

The new implementation is less accurate than the original one as Python
can do anything at import time and cmdtable may be imported from another
module, but I think it's good enough.

Note that the new implementation has to parse .py files, which is slightly
slower than executing .pyc if demandimport is enabled.

from __future__ import absolute_import, print_function

import os
import sys

# make it runnable using python directly without run-tests.py
sys.path[0:0] = [os.path.join(os.path.dirname(__file__), '..')]

# Import something from Mercurial, so the module loader gets initialized.
from mercurial import pycompat
del pycompat  # unused for now

from hgext.lfs import pointer

def tryparse(text):
    r = {}
    try:
        r = pointer.deserialize(text)
        print('ok')
    except Exception as ex:
        print((b'%s' % ex).decode('ascii'))
    if r:
        text2 = r.serialize()
        if text2 != text:
            print('reconstructed text differs')
    return r

t = (b'version https://git-lfs.github.com/spec/v1\n'
     b'oid sha256:4d7a214614ab2935c943f9e0ff69d22eadbb8f32b1'
     b'258daaa5e2ca24d17e2393\n'
     b'size 12345\n'
     b'x-foo extra-information\n')

tryparse(b'')
tryparse(t)
tryparse(t.replace(b'git-lfs', b'unknown'))
tryparse(t.replace(b'v1\n', b'v1\n\n'))
tryparse(t.replace(b'sha256', b'ahs256'))
tryparse(t.replace(b'sha256:', b''))
tryparse(t.replace(b'12345', b'0x12345'))
tryparse(t.replace(b'extra-information', b'extra\0information'))
tryparse(t.replace(b'extra-information', b'extra\ninformation'))
tryparse(t.replace(b'x-foo', b'x_foo'))
tryparse(t.replace(b'oid', b'blobid'))
tryparse(t.replace(b'size', b'size-bytes').replace(b'oid', b'object-id'))