tests/test-pager.t

pager: do not try to run an empty pager command

If pagercmd is explicitly set to '', the pager process would exit silently
and the output would be lost. We'd better disable the pager in such case.

  $ cat >> fakepager.py <<EOF
  > import sys
  > for line in sys.stdin:
  >     sys.stdout.write('paged! %r\n' % line)
  > EOF

Enable ui.formatted because pager won't fire without it, and set up
pager and tell it to use our fake pager that lets us see when the
pager was running.
  $ cat >> $HGRCPATH <<EOF
  > [ui]
  > formatted = yes
  > [extensions]
  > pager=
  > [pager]
  > pager = python $TESTTMP/fakepager.py
  > EOF

  $ hg init repo
  $ cd repo
  $ echo a >> a
  $ hg add a
  $ hg ci -m 'add a'
  $ for x in `python $TESTDIR/seq.py 1 10`; do
  >   echo a $x >> a
  >   hg ci -m "modify a $x"
  > done

By default diff and log are paged, but id is not:

  $ hg diff -c 2 --pager=yes
  paged! 'diff -r f4be7687d414 -r bce265549556 a\n'
  paged! '--- a/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '+++ b/a\tThu Jan 01 00:00:00 1970 +0000\n'
  paged! '@@ -1,2 +1,3 @@\n'
  paged! ' a\n'
  paged! ' a 1\n'
  paged! '+a 2\n'

  $ hg log --limit 2
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

  $ hg id
  46106edeeb38 tip

We can enable the pager on id:

  $ hg --config pager.attend-id=yes id
  paged! '46106edeeb38 tip\n'

Setting attend-$COMMAND to a false value works, even with pager in
core:

  $ hg --config pager.attend-diff=no diff -c 2
  diff -r f4be7687d414 -r bce265549556 a
  --- a/a	Thu Jan 01 00:00:00 1970 +0000
  +++ b/a	Thu Jan 01 00:00:00 1970 +0000
  @@ -1,2 +1,3 @@
   a
   a 1
  +a 2

If 'log' is in attend, then 'history' should also be paged:
  $ hg history --limit 2 --config pager.attend=log
  paged! 'changeset:   10:46106edeeb38\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! 'changeset:   9:6dd8ea7dd621\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'

Pager should not start if stdout is not a tty.

  $ hg log -l1 -q --config ui.formatted=False
  10:46106edeeb38

Pager should be disabled if pager.pager is empty (otherwise the output would
be silently lost.)

  $ hg log -l1 -q --config pager.pager=
  10:46106edeeb38

Pager with color enabled allows colors to come through by default,
even though stdout is no longer a tty.
  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > color=
  > [color]
  > mode = ansi
  > EOF
  $ hg log --limit 3
  paged! '\x1b[0;33mchangeset:   10:46106edeeb38\x1b[0m\n'
  paged! 'tag:         tip\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 10\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   9:6dd8ea7dd621\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 9\n'
  paged! '\n'
  paged! '\x1b[0;33mchangeset:   8:cff05a6312fe\x1b[0m\n'
  paged! 'user:        test\n'
  paged! 'date:        Thu Jan 01 00:00:00 1970 +0000\n'
  paged! 'summary:     modify a 8\n'
  paged! '\n'

Pager works with shell aliases.

  $ cat >> $HGRCPATH <<EOF
  > [alias]
  > echoa = !echo a
  > EOF

  $ hg echoa
  a
  $ hg --config pager.attend-echoa=yes echoa
  paged! 'a\n'

Pager works with hg aliases including environment variables.

  $ cat >> $HGRCPATH <<'EOF'
  > [alias]
  > printa = log -T "$A\n" -r 0
  > EOF

  $ A=1 hg --config pager.attend-printa=yes printa
  paged! '1\n'
  $ A=2 hg --config pager.attend-printa=yes printa
  paged! '2\n'

Something that's explicitly attended is still not paginated if the
pager is globally set to off using a flag:
  $ A=2 hg --config pager.attend-printa=yes printa --pager=no
  2

Pager should not override the exit code of other commands

  $ cat >> $TESTTMP/fortytwo.py <<'EOF'
  > from mercurial import cmdutil, commands
  > cmdtable = {}
  > command = cmdutil.command(cmdtable)
  > @command('fortytwo', [], 'fortytwo', norepo=True)
  > def fortytwo(ui, *opts):
  >     ui.write('42\n')
  >     return 42
  > EOF

  $ cat >> $HGRCPATH <<'EOF'
  > [extensions]
  > fortytwo = $TESTTMP/fortytwo.py
  > EOF

  $ hg fortytwo --pager=on
  paged! '42\n'
  [42]

A command that asks for paging using ui.pager() directly works:
  $ hg blame a
  paged! ' 0: a\n'
  paged! ' 1: a 1\n'
  paged! ' 2: a 2\n'
  paged! ' 3: a 3\n'
  paged! ' 4: a 4\n'
  paged! ' 5: a 5\n'
  paged! ' 6: a 6\n'
  paged! ' 7: a 7\n'
  paged! ' 8: a 8\n'
  paged! ' 9: a 9\n'
  paged! '10: a 10\n'
but not with HGPLAIN
  $ HGPLAIN=1 hg blame a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10
explicit flags work too:
  $ hg blame --pager=no a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10

Put annotate in the ignore list for pager:
  $ cat >> $HGRCPATH <<EOF
  > [pager]
  > ignore = annotate
  > EOF
  $ hg blame a
   0: a
   1: a 1
   2: a 2
   3: a 3
   4: a 4
   5: a 5
   6: a 6
   7: a 7
   8: a 8
   9: a 9
  10: a 10