view tests/test-ui-config.py @ 46667:93e9f448273c

rhg: Add support for automatic fallback to Python

`rhg` is a command-line application that can do a small subset of what
`hg` can. It is written entirely in Rust, which avoids the cost of starting
a Python interpreter and importing many Python modules.
In a script that runs many `hg` commands, this cost can add up.

However making users decide when to use `rhg` instead of `hg` is
not practical as we want the subset of supported functionality
to grow over time.

Instead we introduce "fallback" behavior where, when `rhg` encounters
something (a sub-command, a repository format, …) that is not implemented
in Rust-only, it does nothing but silently start a subprocess of
Python-based `hg` running the same command.
That way `rhg` becomes a drop-in replacement for `hg` that sometimes
goes faster. Whether Python is used should be an implementation detail
not apparent to users (other than through speed).

A new `fallback` value is added to the previously introduced
`rhg.on-unsupported` configuration key. When in this mode, the new
`rhg.fallback-executable` config is determine what command to use
to run a Python-based `hg`.

The previous `rhg.on-unsupported = abort-silent` configuration was designed
to let a wrapper script call `rhg` and then fall back to `hg` based on the
exit code. This is still available, but having fallback behavior built-in
in rhg might be easier for users instead of leaving that script "as an
exercise for the reader".

Using a subprocess like this is not idea, especially when `rhg` is to be
installed in `$PATH` as `hg`, since the other `hg.py` executable needs
to still be available… somewhere. Eventually this could be replaced
by using PyOxidizer to a have a single executable that embeds a Python
interpreter, but only starts it when needed.

Differential Revision: https://phab.mercurial-scm.org/D10093

from __future__ import absolute_import, print_function
from mercurial import (
    dispatch,
    error,
    pycompat,
    ui as uimod,
)
from mercurial.utils import stringutil

testui = uimod.ui.load()

# disable the configuration registration warning
#
# the purpose of this test is to check the old behavior, not to validate the
# behavior from registered item. so we silent warning related to unregisted
# config.
testui.setconfig(b'devel', b'warn-config-unknown', False, b'test')
testui.setconfig(b'devel', b'all-warnings', False, b'test')

parsed = dispatch._parseconfig(
    testui,
    [
        b'values.string=string value',
        b'values.bool1=true',
        b'values.bool2=false',
        b'values.boolinvalid=foo',
        b'values.int1=42',
        b'values.int2=-42',
        b'values.intinvalid=foo',
        b'lists.list1=foo',
        b'lists.list2=foo bar baz',
        b'lists.list3=alice, bob',
        b'lists.list4=foo bar baz alice, bob',
        b'lists.list5=abc d"ef"g "hij def"',
        b'lists.list6="hello world", "how are you?"',
        b'lists.list7=Do"Not"Separate',
        b'lists.list8="Do"Separate',
        b'lists.list9="Do\\"NotSeparate"',
        b'lists.list10=string "with extraneous" quotation mark"',
        b'lists.list11=x, y',
        b'lists.list12="x", "y"',
        b'lists.list13=""" key = "x", "y" """',
        b'lists.list14=,,,,     ',
        b'lists.list15=" just with starting quotation',
        b'lists.list16="longer quotation" with "no ending quotation',
        b'lists.list17=this is \\" "not a quotation mark"',
        b'lists.list18=\n \n\nding\ndong',
        b'date.epoch=0 0',
        b'date.birth=2005-04-19T00:00:00',
        b'date.invalid=0',
    ],
)


def pprint(obj):
    return stringutil.pprint(obj).decode('ascii')


print(pprint(testui.configitems(b'values')))
print(pprint(testui.configitems(b'lists')))
print("---")
print(pprint(testui.config(b'values', b'string')))
print(pprint(testui.config(b'values', b'bool1')))
print(pprint(testui.config(b'values', b'bool2')))
print(pprint(testui.config(b'values', b'unknown')))
print("---")
try:
    print(pprint(testui.configbool(b'values', b'string')))
except error.ConfigError as inst:
    print(pprint(pycompat.bytestr(inst)))
print(pprint(testui.configbool(b'values', b'bool1')))
print(pprint(testui.configbool(b'values', b'bool2')))
print(pprint(testui.configbool(b'values', b'bool2', True)))
print(pprint(testui.configbool(b'values', b'unknown')))
print(pprint(testui.configbool(b'values', b'unknown', True)))
print("---")
print(pprint(testui.configint(b'values', b'int1')))
print(pprint(testui.configint(b'values', b'int2')))
print("---")
print(pprint(testui.configlist(b'lists', b'list1')))
print(pprint(testui.configlist(b'lists', b'list2')))
print(pprint(testui.configlist(b'lists', b'list3')))
print(pprint(testui.configlist(b'lists', b'list4')))
print(pprint(testui.configlist(b'lists', b'list4', [b'foo'])))
print(pprint(testui.configlist(b'lists', b'list5')))
print(pprint(testui.configlist(b'lists', b'list6')))
print(pprint(testui.configlist(b'lists', b'list7')))
print(pprint(testui.configlist(b'lists', b'list8')))
print(pprint(testui.configlist(b'lists', b'list9')))
print(pprint(testui.configlist(b'lists', b'list10')))
print(pprint(testui.configlist(b'lists', b'list11')))
print(pprint(testui.configlist(b'lists', b'list12')))
print(pprint(testui.configlist(b'lists', b'list13')))
print(pprint(testui.configlist(b'lists', b'list14')))
print(pprint(testui.configlist(b'lists', b'list15')))
print(pprint(testui.configlist(b'lists', b'list16')))
print(pprint(testui.configlist(b'lists', b'list17')))
print(pprint(testui.configlist(b'lists', b'list18')))
print(pprint(testui.configlist(b'lists', b'unknown')))
print(pprint(testui.configlist(b'lists', b'unknown', b'')))
print(pprint(testui.configlist(b'lists', b'unknown', b'foo')))
print(pprint(testui.configlist(b'lists', b'unknown', [b'foo'])))
print(pprint(testui.configlist(b'lists', b'unknown', b'foo bar')))
print(pprint(testui.configlist(b'lists', b'unknown', b'foo, bar')))
print(pprint(testui.configlist(b'lists', b'unknown', [b'foo bar'])))
print(pprint(testui.configlist(b'lists', b'unknown', [b'foo', b'bar'])))
print("---")
print(pprint(testui.configdate(b'date', b'epoch')))
print(pprint(testui.configdate(b'date', b'birth')))

print(pprint(testui.config(b'values', b'String')))


def function():
    pass


# values that aren't strings should work
testui.setconfig(b'hook', b'commit', function)
print(function == testui.config(b'hook', b'commit'))

# invalid values
try:
    testui.configbool(b'values', b'boolinvalid')
except error.ConfigError:
    print('boolinvalid')
try:
    testui.configint(b'values', b'intinvalid')
except error.ConfigError:
    print('intinvalid')
try:
    testui.configdate(b'date', b'invalid')
except error.ConfigError:
    print('dateinvalid')