tests/test-diffstat.t

localrepo: create new function for instantiating a local repo object

Today, there is a single local repository class - localrepository. Its
__init__ is responsible for loading the .hg/requires file and taking
different actions depending on what is present.

In addition, extensions may define a "reposetup" function that
monkeypatches constructed repository instances, often by implementing
a derived type and changing the __class__ of the repo instance.

Work around alternate storage backends and partial clone has made it
clear to me that shoehorning all this logic into __init__ and operating
on an existing instance is too convoluted. For example, localrepository
assumes revlog storage and swapping in non-revlog storage requires
overriding e.g. file() to return something that isn't a revlog. I've
authored various patches that either:

a) teach various methods (like file()) about different states and
   taking the appropriate code path at run-time
b) create methods/attributes/callables used for instantiating things
   and populating these in __init__

"a" incurs run-time performance penalties and makes code more
complicated since various functions have a bunch of "if storage is X"
branches.

"b" makes localrepository quickly explode in complexity.

My plan for tackling this problem is to make the local repository type
more dynamic. Instead of a static localrepository class/type that
supports all of the local repository configurations (revlogs vs other,
revlogs with ellipsis, revlog v1 versus revlog v2, etc), we'll
dynamically construct a type providing the implementations that are
needed for the repository on disk, derived from the .hg/requires file
and configuration options. The constructed repository type will be
specialized and methods won't need to be taught about different
implementations nor overloaded.

We may also leverage this functionality for building types that don't
implement all attributes. For example, the "intents" feature allows
commands to declare that they are read only. By dynamically
constructing a repository type, we could return a repository instance
with no attributes related to mutating the repository. This could
include things like a "changelog" property implementation that doesn't
check whether it needs to invalidate the hidden revisions set on every
access.

This commit establishes a function for building a local repository
instance. Future commits will start moving functionality from
localrepository.__init__ to this function. Then we'll start dynamically
changing the returned type depending on options that are present.

This change may seem radical. But it should be fully compatible with
the reposetup() model - at least for now.

Differential Revision: https://phab.mercurial-scm.org/D4563

  $ 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(b"\0") and None
  $ 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(b"\0") and None
  $ 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(-)

Filename without "a/" or "b/" (issue5759):

  $ hg diff --config 'diff.noprefix=1' -c1 --stat --git
   a |  3 +++
   1 files changed, 3 insertions(+), 0 deletions(-)
  $ hg diff --config 'diff.noprefix=1' -c2 --stat --git
   c |  Bin 
   d |    0 
   2 files changed, 0 insertions(+), 0 deletions(-)

  $ hg log --config 'diff.noprefix=1' -r '1:' -p --stat --git
  changeset:   1:3a95b07bb77f
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     appenda
  
   a |  3 +++
   1 files changed, 3 insertions(+), 0 deletions(-)
  
  diff --git a a
  --- a
  +++ a
  @@ -211,3 +211,6 @@
   a
   a
   a
  +a
  +a
  +a
  
  changeset:   2:c60a6c753773
  tag:         tip
  user:        test
  date:        Thu Jan 01 00:00:00 1970 +0000
  summary:     createb
  
   c |  Bin 
   d |    0 
   2 files changed, 0 insertions(+), 0 deletions(-)
  
  diff --git c c
  new file mode 100644
  index e69de29bb2d1d6434b8b29ae775ad8c2e48c5391..f76dd238ade08917e6712764a16a22005a50573d
  GIT binary patch
  literal 1
  Ic${MZ000310RR91
  
  diff --git d d
  new file mode 100644
  

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 .

  $ 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(-)