view tests/test-mq-qrename.t @ 33807:b70029f355a3

tests: verify that peer instances only expose interface members

Our abstract interfaces are more useful if we guarantee that
implementations conform to certain rules. Namely, we want to ensure
that objects implementing interfaces don't expose new public
attributes that aren't part of the interface. That way, as long as
consumers don't access "internal" attributes (those beginning with
"_") then (in theory) objects implementing interfaces can be swapped
out and everything will "just work."

We add a test that enforces our "no public attributes not part
of the abstract interface" rule.

We /could/ implement "interface compliance detection" at run-time.
However, that is littered with problems.

The obvious solutions are custom __new__ and __init__ methods.
These rely on derived types actually calling the parent's
implementation, which is no sure bet. Furthermore, __new__ and
__init__ will likely be called before instance-specific attributes
are assigned. In other words, they won't detect public attributes
set on self.__dict__. This means public attribute detection won't
be robust.

We could work around lack of robust self.__dict__ public attribute
detection by having our interfaces implement a custom __getattribute__,
__getattr__, and/or __setattr__. However, this incurs an undesirable
run-time penalty. And, subclasses could override our custom
method, bypassing the check.

The most robust solution is a non-runtime test. So that's what this
commit implements. We have a generic function for validating that an
object only has public attributes defined by abstract classes. Then,
we instantiate some peers and verify a newly constructed object
plays by the rules.

Differential Revision: https://phab.mercurial-scm.org/D339

  $ echo "[extensions]" >> $HGRCPATH
  $ echo "mq=" >> $HGRCPATH

  $ hg init a
  $ cd a

  $ echo 'base' > base
  $ hg ci -Ambase
  adding base

  $ hg qnew -mmqbase mqbase

  $ hg qrename mqbase renamed
  $ mkdir .hg/patches/foo
  $ hg qrename renamed foo

  $ hg qseries
  foo/renamed

  $ ls .hg/patches/foo
  renamed

  $ mkdir .hg/patches/bar
  $ hg qrename foo/renamed bar

  $ hg qseries
  bar/renamed

  $ ls .hg/patches/bar
  renamed

  $ hg qrename bar/renamed baz

  $ hg qseries
  baz

  $ ls .hg/patches/baz
  .hg/patches/baz

  $ hg qrename baz new/dir

  $ hg qseries
  new/dir

  $ ls .hg/patches/new/dir
  .hg/patches/new/dir

  $ cd ..

Test patch being renamed before committed:

  $ hg init b
  $ cd b
  $ hg qinit -c
  $ hg qnew x
  $ hg qrename y
  $ hg qcommit -m rename

  $ cd ..

Test overlapping renames (issue2388)

  $ hg init c
  $ cd c
  $ hg qinit -c
  $ echo a > a
  $ hg add
  adding a
  $ hg qnew patcha
  $ echo b > b
  $ hg add
  adding b
  $ hg qnew patchb
  $ hg ci --mq -m c1
  $ hg qrename patchb patchc
  $ hg qrename patcha patchb
  $ hg st --mq
  M patchb
  M series
  A patchc
  R patcha
  $ cd ..

Test renames with mq repo (issue2097)

  $ hg init issue2097
  $ cd issue2097
  $ hg qnew p0
  $ (cd .hg/patches && hg init)
  $ hg qren p0 p1
  $ hg debugstate --mq
  $ hg ci --mq -mq0
  nothing changed
  [1]
  $ cd ..

Test renaming to a folded patch (issue3058)

  $ hg init issue3058
  $ cd issue3058
  $ hg init --mq
  $ echo a > a
  $ hg add a
  $ hg qnew adda
  $ echo b >> a
  $ hg qnew addb
  $ hg qpop
  popping addb
  now at: adda
  $ hg ci --mq -m "save mq"
  $ hg qfold addb
  $ hg qmv addb
  $ cat .hg/patches/addb
  # HG changeset patch
  # Parent  0000000000000000000000000000000000000000
  
  diff -r 000000000000 a
  --- /dev/null	* (glob)
  +++ b/a	* (glob)
  @@ -0,0 +1,2 @@
  +a
  +b
  $ cd ..