tests/test-diffstat.t

effectflag: store an empty effect flag for the moment

The idea behind effect flag is to store additional information in obs-markers
about what changed between a changeset and its successor(s). It's a low-level
information that comes without guarantees.

This information can be computed a posteriori, but only if we have all
changesets locally. This is not the case with distributed workflows where you
work with several people or on several computers (eg: laptop + build server).

Storing the effect-flag as a bitfield has several advantages:

- It's compact, we are using one byte per obs-marker at most for the effect-
  flag.
- It's compoundable, the obsfate log approach needs to display evolve history
  that could spans several obs-markers. Computing the effect-flag between a
  changeset and its grand-grand-grand-successor is simple thanks to the
  bitfield.

The effect-flag design has also some limitations:

- Evolving a changeset and reverting these changes just after would lead to
  two obs-markers with the same effect-flag without information that the first
  and third changesets are the same.

The effect-flag current design is a trade-off between compactness and
usefulness.

Storing this information helps commands to display a more complete and
understandable evolve history. For example, obslog (an Evolve command) use it
to improve its output:

x  62206adfd571 (34302) obscache: skip updating outdated obscache...
|    rewritten(parent) by Matthieu Laneuville <matthieu.laneuville@octobus...
|    rewritten(content) by Boris Feld <[e-mail]>

The effect flag is stored in obs-markers metadata while we iterate on the
information we want to store. We plan to extend the existing obsmarkers
bit-field when the effect flag design will be stabilized.

It's different from the CommitCustody concept, effect-flag are not signed and
can be forged. It's also different from the operation metadata as the command
name (for example: amend) could alter a changeset in different ways (changing
the content with hg amend, changing the description with hg amend -e, changing
the user with hg amend -U). Also it's compatible with every custom command
that writes obs-markers without needing to be updated.

The effect-flag is placed behind an experimental flag set to off by default.

Hook the saving of effect flag in create markers, but store only an empty one
for the moment, I will refine the values in effect flag in following patches.

For more information, see:

  https://www.mercurial-scm.org/wiki/ChangesetEvolutionDevel#Record_types_of_operation

Differential Revision: https://phab.mercurial-scm.org/D533

  $ hg init repo
  $ cd repo
  $ i=0; while [ "$i" -lt 213 ]; do echo a >> a; i=`expr $i + 1`; done
  $ hg add a
  $ cp a b
  $ hg add b

Wide diffstat:

  $ hg diff --stat
   a |  213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   b |  213 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++++
   2 files changed, 426 insertions(+), 0 deletions(-)

diffstat width:

  $ COLUMNS=24 hg diff --config ui.interactive=true --stat
   a |  213 ++++++++++++++
   b |  213 ++++++++++++++
   2 files changed, 426 insertions(+), 0 deletions(-)

  $ hg ci -m adda

  $ cat >> a <<EOF
  > a
  > a
  > a
  > EOF

Narrow diffstat:

  $ hg diff --stat
   a |  3 +++
   1 files changed, 3 insertions(+), 0 deletions(-)

  $ hg ci -m appenda

  >>> open("c", "wb").write("\0")
  $ touch d
  $ hg add c d

Binary diffstat:

  $ hg diff --stat
   c |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

Binary git diffstat:

  $ hg diff --stat --git
   c |  Bin 
   d |    0 
   2 files changed, 0 insertions(+), 0 deletions(-)

  $ hg ci -m createb

  >>> open("file with spaces", "wb").write("\0")
  $ hg add "file with spaces"

Filename with spaces diffstat:

  $ hg diff --stat
   file with spaces |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

Filename with spaces git diffstat:

  $ hg diff --stat --git
   file with spaces |  Bin 
   1 files changed, 0 insertions(+), 0 deletions(-)

diffstat within directories:

  $ hg rm -f 'file with spaces'

  $ mkdir dir1 dir2
  $ echo new1 > dir1/new
  $ echo new2 > dir2/new
  $ hg add dir1/new dir2/new
  $ hg diff --stat
   dir1/new |  1 +
   dir2/new |  1 +
   2 files changed, 2 insertions(+), 0 deletions(-)

  $ hg diff --stat --root dir1
   new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ hg diff --stat --root dir1 dir2
  warning: dir2 not inside relative root dir1

  $ hg diff --stat --root dir1 -I dir1/old

  $ cd dir1
  $ hg diff --stat .
   dir1/new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)
  $ hg diff --stat --root .
   new |  1 +
   1 files changed, 1 insertions(+), 0 deletions(-)

  $ hg diff --stat --root ../dir1 ../dir2
  warning: ../dir2 not inside relative root . (glob)

  $ hg diff --stat --root . -I old

  $ cd ..

Files with lines beginning with '--' or '++' should be properly counted in diffstat

  $ hg up -Cr tip
  0 files updated, 0 files merged, 0 files removed, 0 files unresolved
  $ rm dir1/new
  $ rm dir2/new
  $ rm "file with spaces"
  $ cat > file << EOF
  > line 1
  > line 2
  > line 3
  > EOF
  $ hg commit -Am file
  adding file

Lines added starting with '--' should count as additions
  $ cat > file << EOF
  > line 1
  > -- line 2, with dashes
  > line 3
  > EOF

  $ hg diff --root .
  diff -r be1569354b24 file
  --- a/file	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file	* (glob)
  @@ -1,3 +1,3 @@
   line 1
  -line 2
  +-- line 2, with dashes
   line 3

  $ hg diff --root . --stat
   file |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)

Lines changed starting with '--' should count as deletions
  $ hg commit -m filev2
  $ cat > file << EOF
  > line 1
  > -- line 2, with dashes, changed again
  > line 3
  > EOF

  $ hg diff --root .
  diff -r 160f7c034df6 file
  --- a/file	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file	* (glob)
  @@ -1,3 +1,3 @@
   line 1
  --- line 2, with dashes
  +-- line 2, with dashes, changed again
   line 3

  $ hg diff --root . --stat
   file |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)

Lines changed starting with '--' should count as deletions
and starting with '++' should count as additions
  $ cat > file << EOF
  > line 1
  > ++ line 2, switched dashes to plusses
  > line 3
  > EOF

  $ hg diff --root .
  diff -r 160f7c034df6 file
  --- a/file	Thu Jan 01 00:00:00 1970 +0000
  +++ b/file	* (glob)
  @@ -1,3 +1,3 @@
   line 1
  --- line 2, with dashes
  +++ line 2, switched dashes to plusses
   line 3

  $ hg diff --root . --stat
   file |  2 +-
   1 files changed, 1 insertions(+), 1 deletions(-)