view tests/test-releasenotes-merging.t @ 33289:abd7dedbaa36

sparse: vendor Facebook-developed extension

Facebook has developed an extension to enable "sparse" checkouts -
a working directory with a subset of files. This feature is a critical
component in enabling repositories to scale to infinite number of
files while retaining reasonable performance. It's worth noting
that sparse checkout is only one possible solution to this problem:
another is virtual filesystems that realize files on first access.
But given that virtual filesystems may not be accessible to all
users, sparse checkout is necessary as a fallback.

Per mailing list discussion at
https://www.mercurial-scm.org/pipermail/mercurial-devel/2017-March/095868.html
we want to add sparse checkout to the Mercurial distribution via
roughly the following mechanism:

1. Vendor extension as-is with minimal modifications (this patch)
2. Refactor extension so it is more clearly experimental and inline
   with Mercurial practices
3. Move code from extension into core where possible
4. Drop experimental labeling and/or move feature into core
   after sign-off from narrow clone feature owners

This commit essentially copies the sparse extension and tests
from revision 71e0a2aeca92a4078fe1b8c76e32c88ff1929737 of the
https://bitbucket.org/facebook/hg-experimental repository.

A list of modifications made as part of vendoring is as follows:

* "EXPERIMENTAL" added to module docstring
* Imports were changed to match Mercurial style conventions
* "testedwith" value was updated to core Mercurial special value and
  comment boilerplate was inserted
* A "clone_sparse" function was renamed to "clonesparse" to appease
  the style checker
* Paths to the sparse extension in tests reflect built-in location
* test-sparse-extensions.t was renamed to test-sparse-fsmonitor.t
  and references to "simplecache" were removed. The test always skips
  because it isn't trivial to run it given the way we currently run
  fsmonitor tests
* A double empty line was removed from test-sparse-profiles.t

There are aspects of the added code that are obviously not ideal.
The goal is to make a minimal number of modifications as part of
the vendoring to make it easier to track changes from the original
implementation. Refactoring will occur in subsequent patches.

  $ cat >> $HGRCPATH << EOF
  > [extensions]
  > releasenotes=
  > EOF

  $ hg init simple-repo
  $ cd simple-repo

A fix directive from commit message is added to release notes

  $ touch fix1
  $ hg -q commit -A -l - << EOF
  > commit 1
  > 
  > .. fix::
  > 
  >    Fix from commit message.
  > EOF

  $ cat >> $TESTTMP/single-fix-bullet << EOF
  > Bug Fixes
  > =========
  > 
  > * Fix from release notes.
  > EOF

  $ hg releasenotes -r . $TESTTMP/single-fix-bullet

  $ cat $TESTTMP/single-fix-bullet
  Bug Fixes
  =========
  
  * Fix from release notes.
  
  * Fix from commit message.

Processing again ignores the already added bullet.

  $ hg releasenotes -r . $TESTTMP/single-fix-bullet

  $ cat $TESTTMP/single-fix-bullet
  Bug Fixes
  =========
  
  * Fix from release notes.
  
  * Fix from commit message.

  $ cd ..

Sections are unioned

  $ hg init subsections
  $ cd subsections
  $ touch fix1
  $ hg -q commit -A -l - << EOF
  > Commit 1
  > 
  > .. feature:: Commit Message Feature
  > 
  >    This describes a feature from a commit message.
  > EOF

  $ cat >> $TESTTMP/single-feature-section << EOF
  > New Features
  > ============
  > 
  > Notes Feature
  > -------------
  > 
  > This describes a feature from a release notes file.
  > EOF

  $ hg releasenotes -r . $TESTTMP/single-feature-section

  $ cat $TESTTMP/single-feature-section
  New Features
  ============
  
  Notes Feature
  -------------
  
  This describes a feature from a release notes file.
  
  Commit Message Feature
  ----------------------
  
  This describes a feature from a commit message.

Doing it again won't add another section

  $ hg releasenotes -r . $TESTTMP/single-feature-section
  Commit Message Feature already exists in feature section; ignoring

  $ cat $TESTTMP/single-feature-section
  New Features
  ============
  
  Notes Feature
  -------------
  
  This describes a feature from a release notes file.
  
  Commit Message Feature
  ----------------------
  
  This describes a feature from a commit message.

  $ cd ..

Bullets from rev merge with those from notes file.

  $ hg init bullets
  $ cd bullets
  $ touch fix1
  $ hg -q commit -A -l - << EOF
  > commit 1
  > 
  > .. fix::
  > 
  >    this is fix1.
  > EOF

  $ touch fix2
  $ hg -q commit -A -l - << EOF
  > commit 2
  > 
  > .. fix::
  > 
  >    this is fix2.
  > EOF

  $ hg releasenotes -r 'all()' $TESTTMP/relnotes-bullet-problem
  $ cat $TESTTMP/relnotes-bullet-problem
  Bug Fixes
  =========
  
  * this is fix1.
  
  * this is fix2.
  $ touch fix3
  $ hg -q commit -A -l - << EOF
  > commit 3
  > 
  > .. fix::
  > 
  >    this is fix3.
  > EOF

  $ hg releasenotes -r . $TESTTMP/relnotes-bullet-problem
  $ cat $TESTTMP/relnotes-bullet-problem
  Bug Fixes
  =========
  
  * this is fix1.
  
  * this is fix2.
  
  * this is fix3.