view tests/test-custom-filters.t @ 28582:cdbc25306696

run-tests: add --with-python3 to define a Python 3 interpreter

Currently, very few parts of Mercurial run under Python 3, notably the
test harness.

We want to write tests that run Python 3. For example, we want to
extend test-check-py3-compat.t to parse and load Python files.
However, we have a problem: finding appropriate files requires
running `hg files` and this requires Python 2 until `hg` works
with Python 3.

As a temporary workaround, we add --with-python3 to the test harness
to allow us to define the path to a Python 3 interpreter. This
interpreter is made available to the test environment via $PYTHON3 so
tests can run things with Python 3 while the test harness and `hg`
invocations continue to run from Python 2. To round out the feature,
a "py3exe" hghave check has been added.

  $ hg init

  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > prefixfilter = prefix.py
  > [encode]
  > *.txt = stripprefix: Copyright 2046, The Masters
  > [decode]
  > *.txt = insertprefix: Copyright 2046, The Masters
  > EOF

  $ cat > prefix.py <<EOF
  > from mercurial import error
  > def stripprefix(s, cmd, filename, **kwargs):
  >     header = '%s\n' % cmd
  >     if s[:len(header)] != header:
  >         raise error.Abort('missing header "%s" in %s' % (cmd, filename))
  >     return s[len(header):]
  > def insertprefix(s, cmd):
  >     return '%s\n%s' % (cmd, s)
  > def reposetup(ui, repo):
  >     repo.adddatafilter('stripprefix:', stripprefix)
  >     repo.adddatafilter('insertprefix:', insertprefix)
  > EOF

  $ cat > .hgignore <<EOF
  > .hgignore
  > prefix.py
  > prefix.pyc
  > EOF

  $ cat > stuff.txt <<EOF
  > Copyright 2046, The Masters
  > Some stuff to ponder very carefully.
  > EOF
  $ hg add stuff.txt
  $ hg ci -m stuff

Repository data:

  $ hg cat stuff.txt
  Some stuff to ponder very carefully.

Fresh checkout:

  $ rm stuff.txt
  $ hg up -C
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ cat stuff.txt
  Copyright 2046, The Masters
  Some stuff to ponder very carefully.
  $ echo "Very very carefully." >> stuff.txt
  $ hg stat
  M stuff.txt

  $ echo "Unauthorized material subject to destruction." > morestuff.txt

Problem encoding:

  $ hg add morestuff.txt
  $ hg ci -m morestuff
  abort: missing header "Copyright 2046, The Masters" in morestuff.txt
  [255]
  $ hg stat
  M stuff.txt
  A morestuff.txt