tests/test-revert.t

22123:7740db54bf73

  M base
  R allyour
  R ignored
  R newadd

22124:e51784473fc0

  M base
  R allyour
  R ignored
  R newadd

Systematic behavior validation of most possible cases
=====================================================

This section tests most of the possible combinations of working directory
changes and inter-revision changes. The number of possible cases is significant
but they all have a slighly different handling. So this section commits to
generating and testing all of them to allow safe refactoring of the revert code.

A python script is used to generate a file history for each combination of
changes between, on one side the working directory and its parent and on
the other side, changes between a revert target (--rev) and working directory
parent. The three states generated are:

- a "base" revision
- a "parent" revision
- the working directory (based on "parent")

The file generated have names of the form:

 <changeset-state>_<working-copy-state>

Here, "changeset-state" conveys the state in "base" and "parent" (or the change
that happen between them), "working-copy-state" is self explanatory.

All known states are not tested yet. See inline documentation for details.
Special cases from merge and rename are not tested by this section.

There are also multiple cases where the current revert implementation is known to
slightly misbehave.

Write the python script to disk
-------------------------------

  $ cat << EOF > gen-revert-cases.py
  > # generate proper file state to test revert behavior
  > import sys
  > 
  > # content of the file in "base" and "parent"
  > ctxcontent = {
  >     # modified: file content change from base to parent
  >     'modified': ['base', 'parent'],
  > }
  > 
  > # content of file in working copy
  > wccontent = {
  >     # clean: wc content is the same as parent
  >     'clean': lambda cc: cc[1],
  > }
  > 
  > # build the combination of possible states
  > combination = []
  > for ctxkey in ctxcontent:
  >     for wckey in wccontent:
  >         filename = "%s_%s" % (ctxkey, wckey)
  >         combination.append((filename, ctxkey, wckey))
  > 
  > # make sure we have stable output
  > combination.sort()
  > 
  > # retrieve the state we must generate
  > target = sys.argv[1]
  > 
  > # compute file content
  > content = []
  > for filename, ctxkey, wckey in combination:
  >     cc = ctxcontent[ctxkey]
  >     if target == 'base':
  >         content.append((filename, cc[0]))
  >     elif target == 'parent':
  >         content.append((filename, cc[1]))
  >     elif target == 'wc':
  >         content.append((filename, wccontent[wckey](cc)))
  >     else:
  >         print >> sys.stderr, "unknown target:", target
  >         sys.exit(1)
  > 
  > # write actual content
  > for filename, data in content:
  >     f = open(filename, 'w')
  >     f.write(data + '\n')
  >     f.close()
  > EOF


Generate appropriate repo state
-------------------------------

  $ hg init revert-ref
  $ cd revert-ref

Generate base changeset

  $ python ../gen-revert-cases.py base
  $ hg addremove --similarity 0
  adding modified_clean
  $ hg status
  A modified_clean
  $ hg commit -m 'base'

Create parent changeset

  $ python ../gen-revert-cases.py parent
  $ hg addremove --similarity 0
  $ hg status
  M modified_clean
  $ hg commit -m 'parent'

Setup working directory

  $ python ../gen-revert-cases.py wc | cat
  $ hg addremove --similarity 0
  $ hg status

  $ hg status --rev 'desc("base")'
  M modified_clean

  $ cd ..