tests/test-extensions-afterloaded.t

tests: demonstrate crash caused by pinning of non-existent mergestate node

If the mergestate somehow contains a reference to a non-existent node,
it causes most commands to crash since aaeccdb6e654 (repoview: pin
revisions for `local` and `other` when a merge is active,
2020-09-04). This patch adds a test showing that.

Differential Revision: https://phab.mercurial-scm.org/D9077

Test the extensions.afterloaded() function

  $ cat > foo.py <<EOF
  > from mercurial import extensions
  > def uisetup(ui):
  >     ui.write(b"foo.uisetup\\n")
  >     ui.flush()
  >     def bar_loaded(loaded):
  >         ui.write(b"foo: bar loaded: %r\\n" % (loaded,))
  >         ui.flush()
  >     extensions.afterloaded(b'bar', bar_loaded)
  > EOF
  $ cat > bar.py <<EOF
  > def uisetup(ui):
  >     ui.write(b"bar.uisetup\\n")
  >     ui.flush()
  > EOF
  $ basepath=`pwd`

  $ hg init basic
  $ cd basic
  $ echo foo > file
  $ hg add file
  $ hg commit -m 'add file'

  $ echo '[extensions]' >> .hg/hgrc
  $ echo "foo = $basepath/foo.py" >> .hg/hgrc
  $ echo "bar = $basepath/bar.py" >> .hg/hgrc
  $ hg log -r. -T'{rev}\n'
  foo.uisetup
  foo: bar loaded: True
  bar.uisetup
  0

Test afterloaded with the opposite extension load order

  $ cd ..
  $ hg init basic_reverse
  $ cd basic_reverse
  $ echo foo > file
  $ hg add file
  $ hg commit -m 'add file'

  $ echo '[extensions]' >> .hg/hgrc
  $ echo "bar = $basepath/bar.py" >> .hg/hgrc
  $ echo "foo = $basepath/foo.py" >> .hg/hgrc
  $ hg log -r. -T'{rev}\n'
  bar.uisetup
  foo.uisetup
  foo: bar loaded: True
  0

Test the extensions.afterloaded() function when the requested extension is not
loaded

  $ cd ..
  $ hg init notloaded
  $ cd notloaded
  $ echo foo > file
  $ hg add file
  $ hg commit -m 'add file'

  $ echo '[extensions]' >> .hg/hgrc
  $ echo "foo = $basepath/foo.py" >> .hg/hgrc
  $ hg log -r. -T'{rev}\n'
  foo.uisetup
  foo: bar loaded: False
  0

Test the extensions.afterloaded() function when the requested extension is not
configured but fails the minimum version check

  $ cd ..
  $ cat > minvers.py <<EOF
  > minimumhgversion = b'9999.9999'
  > def uisetup(ui):
  >     ui.write(b"minvers.uisetup\\n")
  >     ui.flush()
  > EOF
  $ hg init minversion
  $ cd minversion
  $ echo foo > file
  $ hg add file
  $ hg commit -m 'add file'

  $ echo '[extensions]' >> .hg/hgrc
  $ echo "foo = $basepath/foo.py" >> .hg/hgrc
  $ echo "bar = $basepath/minvers.py" >> .hg/hgrc
  $ hg log -r. -T'{rev}\n'
  (third party extension bar requires version 9999.9999 or newer of Mercurial (current: *); disabling) (glob)
  foo.uisetup
  foo: bar loaded: False
  0

Test the extensions.afterloaded() function when the requested extension is not
configured but fails the minimum version check, using the opposite load order
for the two extensions.

  $ cd ..
  $ hg init minversion_reverse
  $ cd minversion_reverse
  $ echo foo > file
  $ hg add file
  $ hg commit -m 'add file'

  $ echo '[extensions]' >> .hg/hgrc
  $ echo "bar = $basepath/minvers.py" >> .hg/hgrc
  $ echo "foo = $basepath/foo.py" >> .hg/hgrc
  $ hg log -r. -T'{rev}\n'
  (third party extension bar requires version 9999.9999 or newer of Mercurial (current: *); disabling) (glob)
  foo.uisetup
  foo: bar loaded: False
  0