tests/test-editor-filename.t

dirstate-tree: Make Rust DirstateMap bindings go through a trait object

This changeset starts a series that adds an experiment to make status faster
by changing the dirstate (first only in memory and later also on disk) to
be shaped as a tree matching the directory structure, instead of the current
flat collection of entries. The status algorithm can then traverse this tree
dirstate at the same time as it traverses the filesystem.

We (Octobus) have made prototypes that show promising results but are prone
to bitrot. We would like to start upstreaming some experimental Rust code that
goes in this direction, but to avoid disrupting users it should only be
enabled by some run-time opt-in while keeping the existing dirstate structure
and status algorithm as-is.

The `DirstateMap` type and `status` function look like the appropriate
boundary. This adds a new trait that abstracts everything Python bindings need
and makes those bindings go through a `dyn` trait object. Later we’ll have two
implementations of this trait, and the same bindings can use either.

Differential Revision: https://phab.mercurial-scm.org/D10362

Test temp file used with an editor has the expected suffix.

  $ hg init

Create an editor that writes its arguments to stdout and set it to $HGEDITOR.

  $ cat > editor.sh << EOF
  > echo "\$@"
  > exit 1
  > EOF
  $ hg add editor.sh
  $ HGEDITOR="sh $TESTTMP/editor.sh"
  $ export HGEDITOR

Verify that the path for a commit editor has the expected suffix.

  $ hg commit
  *.commit.hg.txt (glob)
  abort: edit failed: sh exited with status 1
  [250]

Verify that the path for a histedit editor has the expected suffix.

  $ cat >> $HGRCPATH <<EOF
  > [extensions]
  > rebase=
  > histedit=
  > EOF
  $ hg commit --message 'At least one commit for histedit.'
  $ hg histedit
  *.histedit.hg.txt (glob)
  abort: edit failed: sh exited with status 1
  [250]

Verify that when performing an action that has the side-effect of creating an
editor for a diff, the file ends in .diff.

  $ echo 1 > one
  $ echo 2 > two
  $ hg add
  adding one
  adding two
  $ hg commit --interactive --config ui.interactive=true --config ui.interface=text << EOF
  > y
  > e
  > q
  > EOF
  diff --git a/one b/one
  new file mode 100644
  examine changes to 'one'?
  (enter ? for help) [Ynesfdaq?] y
  
  @@ -0,0 +1,1 @@
  +1
  record change 1/2 to 'one'?
  (enter ? for help) [Ynesfdaq?] e
  
  *.diff (glob)
  editor exited with exit code 1
  record change 1/2 to 'one'?
  (enter ? for help) [Ynesfdaq?] q
  
  abort: user quit
  [250]