view tests/test-casecollision-merge.t @ 39788:ae531f5e583c

testing: add interface unit tests for file storage

Our strategy for supporting alternate storage backends is to define
interfaces for everything then "code to the interface."

We already have interfaces for various primitives, including file
and manifest storage.

What we don't have is generic unit tests for those interfaces. Up
to this point we've been relying on high-level integration tests
(mainly in the form of existing .t tests) to test alternate storage
backends. And my experience with developing the "simple store" test
extension is that such testing is very tedious: it takes several
minutes to run all tests and when you find a failure, it is often
non-trivial to debug.

This commit starts to change that.

This commit introduces the mercurial.testing.storage module. It
contains testing code for storage. Currently, it defines some
unittest.TestCase classes for testing the file storage interfaces.
It also defines some factory functions that allow a caller to easily
spawn a custom TestCase "bound" to a specific file storage backend
implementation.

A new .py test has been added. It simply defines a callable to produce
filelog and transaction instances on demand and then "registers" the
various test classes so the filelog class can be tested with the
storage interface unit tests.

As part of writing the tests, I identified a couple of apparent
bugs in revlog.py and filelog.py! These are tracked with inline
TODO comments.

Writing the tests makes it more obvious where the storage interface
is lacking. For example, we raise either IndexError or
error.LookupError for missing revisions depending on whether we
use an integer revision or a node. Also, we raise error.RevlogError
in various places when we should be raising a storage-agnostic
error type.

The storage interfaces are currently far from perfect and there is much
work to be done to improve them. But at least with this commit we
finally have the start of unit tests that can be used to "qualify"
the behavior of a storage backend. And when implementing and debugging
new storage backends, we now have an obvious place to define new
tests and have obvious places to insert breakpoints to facilitate
debugging. This should be invaluable when implementing new storage
backends.

I added the mercurial.testing package because these interface
conformance tests are generic and need to be usable by all storage
backends. Having the code live in tests/ would make it difficult for
storage backends implemented in extensions to test their interface
conformance. First, it would require obtaining a copy of Mercurial's
storage test code in order to test. Second, it would make testing
against multiple Mercurial versions difficult, as you would need to
import N copies of the storage testing code in order to achieve test
coverage. By making the test code part of the Mercurial distribution
itself, extensions can `import mercurial.testing.*` to access and run
the test code. The test will run against whatever Mercurial version
is active.

FWIW I've always wanted to move parts of run-tests.py into the
mercurial.* package to make the testing story simpler (e.g. imagine an
`hg debugruntests` command that could invoke the test harness). While I
have no plans to do that in the near future, establishing the
mercurial.testing package does provide a natural home for that code
should someone do this in the future.

Differential Revision: https://phab.mercurial-scm.org/D4650

#require icasefs

################################
test for branch merging
################################

test for rename awareness of case-folding collision check:

(1) colliding file is one renamed from collided file:
this is also case for issue3370.

  $ hg init branch_merge_renaming
  $ cd branch_merge_renaming

  $ echo a > a
  $ hg add a
  $ echo b > b
  $ hg add b
  $ hg commit -m '#0'
  $ hg tag -l A
  $ hg rename a tmp
  $ hg rename tmp A
  $ hg commit -m '#1'
  $ hg tag -l B
  $ hg update -q 0
  $ touch x
  $ hg add x
  $ hg commit -m '#2'
  created new head
  $ hg tag -l C

  $ hg merge -q
  $ hg status -A
  M A
  R a
  C b
  C x

  $ hg update -q --clean 1
  $ hg merge -q
  $ hg status -A
  M x
  C A
  C b
  $ hg commit -m '(D)'
  $ hg tag -l D

additional test for issue3452:

| this assumes the history below.
|
|  (A) -- (C) -- (E) -------
|      \      \             \
|       \      \             \
|         (B) -- (D) -- (F) -- (G)
|
|   A: add file 'a'
|   B: rename from 'a' to 'A'
|   C: add 'x' (or operation other than modification of 'a')
|   D: merge C into B
|   E: modify 'a'
|   F: modify 'A'
|   G: merge E into F
|
| issue3452 occurs when (B) is recorded before (C)

  $ hg update -q --clean C
  $ echo "modify 'a' at (E)" > a
  $ echo "modify 'b' at (E)" > b
  $ hg commit -m '(E)'
  created new head
  $ hg tag -l E

  $ hg update -q --clean D
  $ echo "modify 'A' at (F)" > A
  $ hg commit -m '(F)'
  $ hg tag -l F

  $ hg merge -q --tool internal:other E
  $ hg status -A
  M A
    a
  M b
  C x
  $ cat A
  modify 'a' at (E)

test also the case that (B) is recorded after (C), to prevent
regression by changes in the future.

to avoid unexpected (successful) behavior by filelog unification,
target file is not 'a'/'A' but 'b'/'B' in this case.

  $ hg update -q --clean A
  $ hg rename b tmp
  $ hg rename tmp B
  $ hg commit -m '(B1)'
  created new head
  $ hg tag -l B1

  $ hg merge -q C
  $ hg status -A
  M x
  C B
  C a
  $ hg commit -m '(D1)'
  $ hg tag -l D1

  $ echo "modify 'B' at (F1)" > B
  $ hg commit -m '(F1)'
  $ hg tag -l F1

  $ hg merge -q --tool internal:other E
  $ hg status -A
  M B
    b
  M a
  C x
  $ cat B
  modify 'b' at (E)

  $ cd ..

(2) colliding file is not related to collided file

  $ hg init branch_merge_collding
  $ cd branch_merge_collding

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg remove a
  $ hg commit -m '#1'
  $ echo A > A
  $ hg add A
  $ hg commit -m '#2'
  $ hg update --clean 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ echo x > x
  $ hg add x
  $ hg commit -m '#3'
  created new head
  $ echo 'modified at #4' > a
  $ hg commit -m '#4'

  $ hg merge
  abort: case-folding collision between [aA] and [Aa] (re)
  [255]
  $ hg parents --template '{rev}\n'
  4
  $ hg status -A
  C a
  C x
  $ cat a
  modified at #4

  $ hg update --clean 2
  1 files updated, 0 files merged, 2 files removed, 0 files unresolved
  $ hg merge
  abort: case-folding collision between [aA] and [Aa] (re)
  [255]
  $ hg parents --template '{rev}\n'
  2
  $ hg status -A
  C A
  $ cat A
  A

test for deletion awareness of case-folding collision check (issue3648):
revision '#3' doesn't change 'a', so 'a' should be recognized as
safely removed in merging between #2 and #3.

  $ hg update --clean 3
  2 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg status -A
  M A
  R a
  C x

  $ hg update --clean 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg merge 3
  1 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)
  $ hg status -A
  M x
  C A

  $ cd ..

Prepare for tests of directory case-folding collisions

  $ hg init directory-casing
  $ cd directory-casing
  $ touch 0 # test: file without directory
  $ mkdir 0a
  $ touch 0a/f
  $ mkdir aA
  $ touch aA/a
  $ hg ci -Aqm0

Directory/file case-folding collision:

  $ hg up -q null
  $ touch 00 # test: starts as '0'
  $ mkdir 000 # test: starts as '0'
  $ touch 000/f
  $ touch Aa # test: collision with 'aA/a'
  $ hg ci -Aqm1

  $ hg merge 0
  abort: case-folding collision between Aa and directory of aA/a
  [255]
(note: no collision between 0 and 00 or 000/f)

Directory case-folding collision:

  $ hg up -qC null
  $ hg --config extensions.purge= purge
  $ mkdir 0A0
  $ touch 0A0/f # test: starts as '0a'
  $ mkdir Aa
  $ touch Aa/b # test: collision with 'aA/a'
  $ hg ci -Aqm2

  $ hg merge 0
  3 files updated, 0 files merged, 0 files removed, 0 files unresolved
  (branch merge, don't forget to commit)

  $ cd ..

################################
test for linear updates
################################

test for rename awareness of case-folding collision check:

(1) colliding file is one renamed from collided file

  $ hg init linearupdate_renameaware_1
  $ cd linearupdate_renameaware_1

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg rename a tmp
  $ hg rename tmp A
  $ hg commit -m '#1'

  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo 'this is added line' >> a
  $ hg update 1
  merging a and A to A
  0 files updated, 1 files merged, 0 files removed, 0 files unresolved
  $ hg status -A
  M A
  $ cat A
  a
  this is added line

  $ cd ..

(2) colliding file is not related to collided file

  $ hg init linearupdate_renameaware_2
  $ cd linearupdate_renameaware_2

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg remove a
  $ hg commit -m '#1'
  $ echo A > A
  $ hg add A
  $ hg commit -m '#2'

  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  0
  $ hg status -A
  C a
  $ cat A
  a
  $ hg up -qC 2

  $ hg update --check 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  0
  $ hg status -A
  C a
  $ cat a
  a

  $ hg update --clean 2
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  2
  $ hg status -A
  C A
  $ cat A
  A

  $ cd ..

(3) colliding file is not related to collided file: added in working dir

  $ hg init linearupdate_renameaware_3
  $ cd linearupdate_renameaware_3

  $ echo a > a
  $ hg add a
  $ hg commit -m '#0'
  $ hg rename a b
  $ hg commit -m '#1'
  $ hg update 0
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved

  $ echo B > B
  $ hg add B
  $ hg status
  A B
  $ hg update
  abort: case-folding collision between [bB] and [Bb] (re)
  [255]

  $ hg update --check
  abort: uncommitted changes
  [255]

  $ hg update --clean
  1 files updated, 0 files merged, 1 files removed, 0 files unresolved
  $ hg parents --template '{rev}\n'
  1
  $ hg status -A
  C b
  $ cat b
  a

  $ cd ..