fileset: add a lightweight file filtering language
This patch was inspired by one that Jun Wu authored for the fb-experimental
repo, to avoid using matcher for efficiency[1]. We want a way to specify what
files will be converted to LFS at commit time. And per discussion, we also want
to specify what files to skip, text diff, or merge in another config option.
The current `lfs.threshold` config option could not satisfy complex needs. I'm
putting it in a core package because Augie floated the idea of also using it for
narrow and sparse.
Yuya suggested farming out to fileset.parse(), which added support for more
symbols. The only fileset element not supported here is 'negate'. (List isn't
supported by filesets either.) I also changed the 'always' token to the 'all()'
predicate for consistency, and introduced 'none()' to improve readability in a
future tracked file based config. The extension operator was changed from '.'
to '**', to match how recursive path globs are specified. Finally, I changed
the path matcher from '/' to 'path:' at Yuya's suggestion, for consistency with
matcher. Unfortunately, ':' is currently reserved in filesets, so this has to
be quoted to be processed as a string instead of a symbol[2]. We should
probably revisit that, because it's seriously ugly. But it's only used by an
experimental extension, and I think using a file based config for LFS may drive
some more tweaks, so I'm settling for this for now.
I reserved all of the glob characters in fileset except '.' and '_' for the
extension test because those are likely valid extension characters.
Sample filter settings:
all() # everything
size(">20MB") # larger than 20MB
!**.txt # except for .txt files
**.zip | **.tar.gz | **.7z # some types of compressed files
"path:bin" # files under "bin" in the project root
[1] https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-December/109387.html
[2] https://www.mercurial-scm.org/pipermail/mercurial-devel/2018-January/109729.html
#require test-repo
$ . "$TESTDIR/helpers-testrepo.sh"
$ testrepohgenv
$ import_checker="$TESTDIR"/../contrib/import-checker.py
Run the doctests from the import checker, and make sure
it's working correctly.
$ TERM=dumb
$ export TERM
$ $PYTHON -m doctest $import_checker
Run additional tests for the import checker
$ mkdir testpackage
$ touch testpackage/__init__.py
$ cat > testpackage/multiple.py << EOF
> from __future__ import absolute_import
> import os, sys
> EOF
$ cat > testpackage/unsorted.py << EOF
> from __future__ import absolute_import
> import sys
> import os
> EOF
$ cat > testpackage/stdafterlocal.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> import os
> EOF
$ cat > testpackage/requirerelative.py << EOF
> from __future__ import absolute_import
> import testpackage.unsorted
> EOF
$ cat > testpackage/importalias.py << EOF
> from __future__ import absolute_import
> import ui
> EOF
$ cat > testpackage/relativestdlib.py << EOF
> from __future__ import absolute_import
> from .. import os
> EOF
$ cat > testpackage/symbolimport.py << EOF
> from __future__ import absolute_import
> from .unsorted import foo
> EOF
$ cat > testpackage/latesymbolimport.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> from mercurial.node import hex
> EOF
$ cat > testpackage/multiplegroups.py << EOF
> from __future__ import absolute_import
> from . import unsorted
> from . import more
> EOF
$ mkdir testpackage/subpackage
$ cat > testpackage/subpackage/levelpriority.py << EOF
> from __future__ import absolute_import
> from . import foo
> from .. import parent
> EOF
$ touch testpackage/subpackage/foo.py
$ cat > testpackage/subpackage/__init__.py << EOF
> from __future__ import absolute_import
> from . import levelpriority # should not cause cycle
> EOF
$ cat > testpackage/subpackage/localimport.py << EOF
> from __future__ import absolute_import
> from . import foo
> def bar():
> # should not cause "higher-level import should come first"
> from .. import unsorted
> # but other errors should be detected
> from .. import more
> import testpackage.subpackage.levelpriority
> EOF
$ cat > testpackage/importmodulefromsub.py << EOF
> from __future__ import absolute_import
> from .subpackage import foo # not a "direct symbol import"
> EOF
$ cat > testpackage/importsymbolfromsub.py << EOF
> from __future__ import absolute_import
> from .subpackage import foo, nonmodule
> EOF
$ cat > testpackage/sortedentries.py << EOF
> from __future__ import absolute_import
> from . import (
> foo,
> bar,
> )
> EOF
$ cat > testpackage/importfromalias.py << EOF
> from __future__ import absolute_import
> from . import ui
> EOF
$ cat > testpackage/importfromrelative.py << EOF
> from __future__ import absolute_import
> from testpackage.unsorted import foo
> EOF
$ mkdir testpackage2
$ touch testpackage2/__init__.py
$ cat > testpackage2/latesymbolimport.py << EOF
> from __future__ import absolute_import
> from testpackage import unsorted
> from mercurial.node import hex
> EOF
# Shadowing a stdlib module to test "relative import of stdlib module" is
# allowed if the module is also being checked
$ mkdir email
$ touch email/__init__.py
$ touch email/errors.py
$ cat > email/utils.py << EOF
> from __future__ import absolute_import
> from . import errors
> EOF
$ $PYTHON "$import_checker" testpackage*/*.py testpackage/subpackage/*.py \
> email/*.py
testpackage/importalias.py:2: ui module must be "as" aliased to uimod
testpackage/importfromalias.py:2: ui from testpackage must be "as" aliased to uimod
testpackage/importfromrelative.py:2: import should be relative: testpackage.unsorted
testpackage/importfromrelative.py:2: direct symbol import foo from testpackage.unsorted
testpackage/importsymbolfromsub.py:2: direct symbol import nonmodule from testpackage.subpackage
testpackage/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
testpackage/multiple.py:2: multiple imported names: os, sys
testpackage/multiplegroups.py:3: multiple "from . import" statements
testpackage/relativestdlib.py:2: relative import of stdlib module
testpackage/requirerelative.py:2: import should be relative: testpackage.unsorted
testpackage/sortedentries.py:2: imports from testpackage not lexically sorted: bar < foo
testpackage/stdafterlocal.py:3: stdlib import "os" follows local import: testpackage
testpackage/subpackage/levelpriority.py:3: higher-level import should come first: testpackage
testpackage/subpackage/localimport.py:7: multiple "from .. import" statements
testpackage/subpackage/localimport.py:8: import should be relative: testpackage.subpackage.levelpriority
testpackage/symbolimport.py:2: direct symbol import foo from testpackage.unsorted
testpackage/unsorted.py:3: imports not lexically sorted: os < sys
testpackage2/latesymbolimport.py:3: symbol import follows non-symbol import: mercurial.node
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