view tests/test-histedit-fold-non-commute.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

  $ . "$TESTDIR/histedit-helpers.sh"

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

  $ modwithdate ()
  > {
  >     echo $1 > $1
  >     hg ci -m $1 -d "$2 0"
  > }

  $ initrepo ()
  > {
  >     hg init $1
  >     cd $1
  >     for x in a b c d e f ; do
  >         echo $x$x$x$x$x > $x
  >         hg add $x
  >     done
  >     hg ci -m 'Initial commit'
  >     modwithdate a 1
  >     modwithdate b 2
  >     modwithdate c 3
  >     modwithdate d 4
  >     modwithdate e 5
  >     modwithdate f 6
  >     echo 'I can haz no commute' > e
  >     hg ci -m 'does not commute with e' -d '7 0'
  >     cd ..
  > }

  $ initrepo r
  $ cd r
Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'fold {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  fold 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (fold 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ HGEDITOR=cat hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  d
  ***
  does not commute with e
  
  
  
  HG: Enter commit message.  Lines beginning with 'HG:' are removed.
  HG: Leave message empty to abort commit.
  HG: --
  HG: user: test
  HG: branch 'default'
  HG: changed d
  HG: changed e
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
keep the non-commuting change, and thus the pending change will be dropped
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg diff
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:1300355b1a54
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:e2ac33269083
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

  $ cd ..

Repeat test using "roll", not "fold". "roll" folds in changes but drops message and date

  $ initrepo r2
  $ cd r2

Initial generation of the command files

  $ EDITED="$TESTTMP/editedhistory.2"
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 3 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 4 >> $EDITED
  $ hg log --template 'roll {node|short} {rev} {desc}\n' -r 7 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 5 >> $EDITED
  $ hg log --template 'pick {node|short} {rev} {desc}\n' -r 6 >> $EDITED
  $ cat $EDITED
  pick 092e4ce14829 3 c
  pick ae78f4c9d74f 4 d
  roll 42abbb61bede 7 does not commute with e
  pick 7f3755409b00 5 e
  pick dd184f2faeb0 6 f

log before edit
  $ hg log --graph
  @  changeset:   7:42abbb61bede
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:07 1970 +0000
  |  summary:     does not commute with e
  |
  o  changeset:   6:dd184f2faeb0
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   5:7f3755409b00
  |  user:        test
  |  date:        Thu Jan 01 00:00:05 1970 +0000
  |  summary:     e
  |
  o  changeset:   4:ae78f4c9d74f
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

edit the history
  $ hg histedit 3 --commands $EDITED 2>&1 | fixbundle
  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (roll 42abbb61bede)
  (hg histedit --continue to resume)

fix up
  $ echo 'I can haz no commute' > e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle | grep -v '2 files removed'
  merging e
  warning: conflicts while merging e! (edit, then use 'hg resolve --mark')
  Fix up the change (pick 7f3755409b00)
  (hg histedit --continue to resume)

just continue this time
  $ hg revert -r 'p1()' e
  $ hg resolve --mark e
  (no more unresolved files)
  continue: hg histedit --continue
  $ hg histedit --continue 2>&1 | fixbundle
  7f3755409b00: skipping changeset (no changes)

log after edit
  $ hg log --graph
  @  changeset:   5:b538bcb461be
  |  tag:         tip
  |  user:        test
  |  date:        Thu Jan 01 00:00:06 1970 +0000
  |  summary:     f
  |
  o  changeset:   4:317e37cb6d66
  |  user:        test
  |  date:        Thu Jan 01 00:00:04 1970 +0000
  |  summary:     d
  |
  o  changeset:   3:092e4ce14829
  |  user:        test
  |  date:        Thu Jan 01 00:00:03 1970 +0000
  |  summary:     c
  |
  o  changeset:   2:40ccdd8beb95
  |  user:        test
  |  date:        Thu Jan 01 00:00:02 1970 +0000
  |  summary:     b
  |
  o  changeset:   1:cd997a145b29
  |  user:        test
  |  date:        Thu Jan 01 00:00:01 1970 +0000
  |  summary:     a
  |
  o  changeset:   0:1715188a53c7
     user:        test
     date:        Thu Jan 01 00:00:00 1970 +0000
     summary:     Initial commit
  

contents of e
  $ hg cat e
  I can haz no commute

manifest
  $ hg manifest
  a
  b
  c
  d
  e
  f

description is taken from rollup target commit

  $ hg log --debug --rev 4
  changeset:   4:317e37cb6d66c1c84628c00e5bf4c8c292831951
  phase:       draft
  parent:      3:092e4ce14829f4974399ce4316d59f64ef0b6725
  parent:      -1:0000000000000000000000000000000000000000
  manifest:    4:b068a323d969f22af1296ec6a5ea9384cef437ac
  user:        test
  date:        Thu Jan 01 00:00:04 1970 +0000
  files:       d e
  extra:       branch=default
  extra:       histedit_source=ae78f4c9d74ffa4b6cb5045001c303fe9204e890,42abbb61bede6f4366fa1e74a664343e5d558a70
  description:
  d
  
  

done with repo r2

  $ cd ..