tests/test-sparse-fsmonitor.t

wireproto: syntax for encoding CBOR into frames

We just vendored a library for encoding and decoding the CBOR
data format. While the intent of that vendor was to support state
files, CBOR is really a nice data format. It is extensible and
compact.

I've been feeling dirty inventing my own data formats for
frame payloads. While custom formats can always beat out a generic
format, there is a cost to be paid in terms of implementation,
comprehension, etc. CBOR is compact enough that I'm not too
worried about efficiency loss. I think the benefits of using
a standardized format outweigh rolling our own formats. So
I plan to make heavy use of CBOR in the wire protocol going
forward.

This commit introduces support for encoding CBOR data in frame
payloads to our function to make a frame from a human string.
We do need to employ some low-level Python code in order to
evaluate a string as a Python expression. But other than that,
this should hopefully be pretty straightforward.

Unit tests for this function have been added.

Differential Revision: https://phab.mercurial-scm.org/D2948

This test doesn't yet work due to the way fsmonitor is integrated with test runner

  $ exit 80

test sparse interaction with other extensions

  $ hg init myrepo
  $ cd myrepo
  $ cat > .hg/hgrc <<EOF
  > [extensions]
  > sparse=
  > strip=
  > EOF

Test fsmonitor integration (if available)
TODO: make fully isolated integration test a'la https://github.com/facebook/watchman/blob/master/tests/integration/WatchmanInstance.py
(this one is using the systemwide watchman instance)

  $ touch .watchmanconfig
  $ echo "ignoredir1/" >> .hgignore
  $ hg commit -Am ignoredir1
  adding .hgignore
  $ echo "ignoredir2/" >> .hgignore
  $ hg commit -m ignoredir2

  $ hg sparse --reset
  $ hg sparse -I ignoredir1 -I ignoredir2 -I dir1

  $ mkdir ignoredir1 ignoredir2 dir1
  $ touch ignoredir1/file ignoredir2/file dir1/file

Run status twice to compensate for a condition in fsmonitor where it will check
ignored files the second time it runs, regardless of previous state (ask @sid0)
  $ hg status --config extensions.fsmonitor=
  ? dir1/file
  $ hg status --config extensions.fsmonitor=
  ? dir1/file

Test that fsmonitor ignore hash check updates when .hgignore changes

  $ hg up -q ".^"
  $ hg status --config extensions.fsmonitor=
  ? dir1/file
  ? ignoredir2/file