tests/test-module-imports.t

template: add revset() template function

Adds a template function that executes a revset and returns the list of
revisions as the result. It has the signature 'revset(query [, args...])'. The
args are optional and are applied to the query string using the standard
python string.format(args) pattern. This allows things like:
'{revset("parents({0})", rev)}' to produce the parents of each individual
commit in the log output.  If no args are specified, the revset result is
cached for the duration of the templater; so it's better to not use args if
performance is a concern.

By itself, revset() can be used to print commit parents, print the common
ancestor of a commit with the main branch, etc.

It can be used with the ifcontains() function to do things like
'{ifcontains(rev, revset('.'), label(...), ...)}' to color the working copy
parent, to color certain branches, to color draft commits, etc.

This code uses the ast module, which was new in 2.6, so we'll skip
this test on anything earlier.
  $ python -c 'import sys ; assert sys.version_info >= (2, 6)' || exit 80

  $ 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

  $ cd "$TESTDIR"/..
  $ if hg identify -q > /dev/null 2>&1; then :
  > else
  >     echo "skipped: not a Mercurial working dir" >&2
  >     exit 80
  > fi

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' | sed 's-\\-/-g' | xargs python "$import_checker"
  mercurial/dispatch.py mixed imports
     stdlib:    commands
     relative:  error, extensions, fancyopts, hg, hook, util
  mercurial/fileset.py mixed imports
     stdlib:    parser
     relative:  error, merge, util
  mercurial/revset.py mixed imports
     stdlib:    parser
     relative:  discovery, error, hbisect, phases, util
  mercurial/templater.py mixed imports
     stdlib:    parser
     relative:  config, error, templatefilters, templatekw, util
  mercurial/ui.py mixed imports
     stdlib:    formatter
     relative:  config, error, scmutil, util
  Import cycle: mercurial.cmdutil -> mercurial.context -> mercurial.subrepo -> mercurial.cmdutil -> mercurial.cmdutil