# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at fb.com>
# Date 1403710626 -3600
# Wed Jun 25 16:37:06 2014 +0100
# Node ID 5878ef23eb3066d139453bf444e15047ddcf2d40
# Parent 19b0133c70f71c940b644573048321b4846e0ddc
test-revert: prepare methodical testing of revert cases
We introduce a script to generate revert cases and use it to prepare a test
repo. See the inline documentation for details.
diff --git a/tests/test-revert.t b/tests/test-revert.t
--- a/tests/test-revert.t
+++ b/tests/test-revert.t
@@ -392,6 +392,123 @@ revert file added by p2() to p1() state
M base
R allyour
R ignored
R newadd
+Systematic behavior validation of most possible case
+====================================================
+This section tests most of the possible combination 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 commit to
+generate and teste 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 name of the form:
+
+ <changeset-state>_<working-copy-state>
+
+Here, "changeset-state" convey 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 is also multiple case where the current revert implementation is known to
+slightly misbehaves.
+
+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 state
+ > 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 ..
+