view tests/test-journal-exists.t @ 41506:3e89736b98ce

py3: conditionalize test-demandimport.py for Python 3

The Python 3 lazy importer uses the LazyLoader that is part of
importlib.

On Python 3 and later, LazyLoader is implemented using a custom module
type that defines a __getattribute__ which triggers module loading.

Furthermore, there are additional differences as well. For example,
it appears that Python 3 will return an existing sys.modules
entry instead of constructing a new module object.

This commit adds additional test coverage for lazy importing
behavior to cover the differences between Python 2 and 3. This
reveals that the test and some lazy import functionality is kinda
busted. For example, the test assumes "contextlib" will be lazy.
But in reality an import before it has already imported contextlib!

There's definitely room to improve the behavior of the demand
importer code, both for Python 2 and 3. But at least the test
passes on Python 3 now.

Differential Revision: https://phab.mercurial-scm.org/D5796

  $ hg init
  $ echo a > a
  $ hg ci -Am0
  adding a

  $ hg -q clone . foo

  $ touch .hg/store/journal

  $ echo foo > a
  $ hg ci -Am0
  abort: abandoned transaction found!
  (run 'hg recover' to clean up transaction)
  [255]

  $ hg recover
  rolling back interrupted transaction
  checking changesets
  checking manifests
  crosschecking files in changesets and manifests
  checking files
  checked 1 changesets with 1 changes to 1 files

Check that zero-size journals are correctly aborted:

#if unix-permissions no-root
  $ hg bundle -qa repo.hg
  $ chmod -w foo/.hg/store/00changelog.i

  $ hg -R foo unbundle repo.hg
  adding changesets
  abort: Permission denied: '$TESTTMP/foo/.hg/store/.00changelog.i-*' (glob)
  [255]

  $ if test -f foo/.hg/store/journal; then echo 'journal exists :-('; fi
#endif