tests/test-parents.t

rust-cpython: prepare for writing tests that require libpython

What I wanted is to disable the "cpython/extension-module<ver>" feature
while building tests executable, but that seems not doable. Instead,
this patch adds new features dedicated for tests.

The make rule is extracted so that we can easily run cargo tests.

Added a minimal test of ref-sharing as an example. More tests will follow.

test parents command

  $ hg init repo
  $ cd repo

no working directory

  $ hg parents

  $ echo a > a
  $ echo b > b
  $ hg ci -Amab -d '0 0'
  adding a
  adding b
  $ echo a >> a
  $ hg ci -Ama -d '1 0'
  $ echo b >> b
  $ hg ci -Amb -d '2 0'
  $ echo c > c
  $ hg ci -Amc -d '3 0'
  adding c
  $ hg up -C 1
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo d > c
  $ hg ci -Amc2 -d '4 0'
  adding c
  created new head
  $ hg up -C 3
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved


  $ hg parents
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  

  $ hg parents a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

hg parents c, single revision

  $ hg parents c
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  

  $ hg parents -r 3 c
  abort: 'c' not found in manifest!
  [255]

  $ hg parents -r 2
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

  $ hg parents -r 2 a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  

  $ hg parents -r 2 ../a
  abort: ../a not under root '$TESTTMP/repo'
  [255]


cd dir; hg parents -r 2 ../a

  $ mkdir dir
  $ cd dir
  $ hg parents -r 2 ../a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  
  $ hg parents -r 2 path:a
  changeset:   1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:01 1970 +0000
  summary:     a
  
  $ cd ..

  $ hg parents -r 2 glob:a
  abort: can only specify an explicit filename
  [255]


merge working dir with 2 parents, hg parents c

  $ HGMERGE=true hg merge
  merging c
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg parents c
  changeset:   3:02d851b7e549
  user:        test
  date:        Thu Jan 01 00:00:03 1970 +0000
  summary:     c
  
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  


merge working dir with 1 parent, hg parents

  $ hg up -C 2
  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ HGMERGE=true hg merge -r 4
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg parents
  changeset:   2:6cfac479f009
  user:        test
  date:        Thu Jan 01 00:00:02 1970 +0000
  summary:     b
  
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  

merge working dir with 1 parent, hg parents c

  $ hg parents c
  changeset:   4:48cee28d4b4e
  tag:         tip
  parent:      1:d786049f033a
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  summary:     c2
  

  $ cd ..