[PATCH 02 of 17] obsolescence: add test for the "branch replacement" logic during push, case A1

[Pierre-Yves David]

# HG changeset patch
# User Pierre-Yves David <pierre-yves.david at ens-lyon.org>
# Date 1492093366 -7200
#      Thu Apr 13 16:22:46 2017 +0200
# Node ID 333e1a68d81e20aaed1569cf1749b0028b294efb
# Parent  dabd8890b002c3cf3ae59526a956404b381e6d3e
# EXP-Topic push.checkheads
# Available At https://www.mercurial-scm.org/repo/users/marmoute/mercurial/
#              hg pull https://www.mercurial-scm.org/repo/users/marmoute/mercurial/ -r 333e1a68d81e
obsolescence: add test for the "branch replacement" logic during push, case A1

Mercurial checks for the introduction of new heads on push. Evolution comes
into play to detect if existing branches on the server are being replaced by
some of the new one we push.

The current code for this logic is very basic (eg: issue4354) and was poorly
tested. We have a better implementation coming in the evolve extension fixing
these issues and with more serious tests coverage. In the process of upstreaming
this improved logic, we start with adding the test case that are already passing
with the current implementation. Once they are all in, we'll upstream the better
implementation and the extra test case.

See inline documentation for details about the test case added in this
changeset.

diff --git a/tests/test-push-checkheads-superceed-A1.t b/tests/test-push-checkheads-superceed-A1.t
new file mode 100644
--- /dev/null
+++ b/tests/test-push-checkheads-superceed-A1.t
@@ -0,0 +1,69 @@
+====================================
+Testing head checking code: Case A-1
+====================================
+
+Mercurial checks for the introduction of new heads on push. Evolution comes
+into play to detect if existing branches on the server are being replaced by
+some of the new one we push.
+
+This case is part of a series of tests checking this behavior.
+
+Category A: simple case involving a branch being superceeded by another.
+TestCase 1: single-changeset branch
+
+.. old-state:
+..
+.. * 1 changeset branch
+..
+.. new-state:
+..
+.. * 1 changeset branch succeeding to A
+..
+.. expected-result:
+..
+.. * push allowed
+..
+.. graph-summary:
+..
+..   A ø⇠◔ A'
+..     |/
+..     ●
+
+  $ . $TESTDIR/testlib/push-checkheads-util.sh
+
+Test setup
+----------
+
+  $ mkdir A1
+  $ cd A1
+  $ setuprepos
+  creating basic server and client repo
+  updating to branch default
+  2 files updated, 0 files merged, 0 files removed, 0 files unresolved
+  $ cd client
+  $ hg up 0
+  0 files updated, 0 files merged, 1 files removed, 0 files unresolved
+  $ mkcommit A1
+  created new head
+  $ hg debugobsolete `getid "desc(A0)" ` `getid "desc(A1)"`
+  $ hg log -G --hidden
+  @  f6082bc4ffef (draft): A1
+  |
+  | x  8aaa48160adc (draft): A0
+  |/
+  o  1e4be0697311 (public): root
+  
+
+Actual testing
+--------------
+
+  $ hg push
+  pushing to $TESTTMP/A1/server (glob)
+  searching for changes
+  adding changesets
+  adding manifests
+  adding file changes
+  added 1 changesets with 1 changes to 1 files (+1 heads)
+  1 new obsolescence markers
+
+  $ cd ../..