view tests/test-logtoprocess.t @ 29859:a1092e2d70a3

help: internals topic for wire protocol

The Mercurial wire protocol is under-documented. This includes a lack
of source docstrings and comments as well as pages on the official
wiki.

This patch adds the beginnings of "internals" documentation on the
wire protocol.

The documentation should have nearly complete coverage on the
lower-level parts of the protocol, such as the different transport
mechanims, how commands and arguments are sent, capabilities, and,
of course, the commands themselves.

As part of writing this documentation, I discovered a number of
deficiencies in the protocol and bugs in the implementation. I've
started sending patches for some of the issues. I hope to send a lot
more.

This patch starts with the scaffolding for a new internals page.

Test if logtoprocess correctly captures command-related log calls.

  $ hg init
  $ cat > $TESTTMP/foocommand.py << EOF
  > from mercurial import cmdutil
  > from time import sleep
  > cmdtable = {}
  > command = cmdutil.command(cmdtable)
  > @command('foo', [])
  > def foo(ui, repo):
  >     ui.log('foo', 'a message: %(bar)s\n', bar='spam')
  > EOF
  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > logtoprocess=
  > foocommand=$TESTTMP/foocommand.py
  > [logtoprocess]
  > command=echo 'logtoprocess command output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1";
  >     echo "\$MSG2"
  > commandfinish=echo 'logtoprocess commandfinish output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1";
  >     echo "\$MSG2";
  >     echo "\$MSG3"
  > foo=echo 'logtoprocess foo output:';
  >     echo "\$EVENT";
  >     echo "\$MSG1";
  >     echo "\$OPT_BAR"
  > EOF

Running a command triggers both a ui.log('command') and a
ui.log('commandfinish') call. The foo command also uses ui.log.

Use head to ensure we wait for all lines to be produced, and sort to avoid
ordering issues between the various processes we spawn:
  $ hg foo | head -n 17 | sort
  
  
  
  0
  a message: spam
  command
  commandfinish
  foo
  foo
  foo
  foo
  foo exited 0 after * seconds (glob)
  logtoprocess command output:
  logtoprocess commandfinish output:
  logtoprocess foo output:
  spam