#require test-repo

  $ 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

  $ 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/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

  $ python "$import_checker" testpackage/*.py testpackage/subpackage/*.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 from testpackage.unsorted

  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 follows local import: os

  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 from testpackage.unsorted

  testpackage/unsorted.py:3: imports not lexically sorted: os < sys

  [1]

  $ cd "$TESTDIR"/..

There are a handful of cases here that require renaming a module so it

doesn't overlap with a stdlib module name. There are also some cycles

here that we should still endeavor to fix, and some cycles will be

hidden by deduplication algorithm in the cycle detector, so fixing

these may expose other cycles.

  $ hg locate 'mercurial/**.py' 'hgext/**.py' | sed 's-\\-/-g' | python "$import_checker" -

  Import cycle: hgext.largefiles.basestore -> hgext.largefiles.localstore -> hgext.largefiles.basestore

  [1]