Move test suite docs to the wiki

tests/README

@@ -1,93 +1,7 b''
-A simple testing framework
-
 To run the tests, do:
 
 cd tests/
 python run-tests.py
 
-This finds all scripts in the test directory named test-* and executes
-them. The scripts can be either shell scripts or Python. Each test is
-run in a temporary directory that is removed when the test is complete.
-
-A test-<x> succeeds if the script returns success and its output
-matches test-<x>.out. If the new output doesn't match, it is stored in
-test-<x>.err.
-
-There are some tricky points here that you should be aware of when
-writing tests:
-
-- hg commit and hg merge want user interaction
-
-  for commit use -m "text"
-  for hg merge, set HGMERGE to something noninteractive (like true or merge)
-
-- changeset hashes will change based on user and date which make
-  things like hg history output change
-
-  use commit -m "test" -u test -d "1000000 0"
-
-- diff and export may show the current time
-
-  use -D/--nodates to strip the dates
-
-- You can append your own hgrc settings to the file that the environment
-  variable HGRCPATH points to. This file is cleared before running a test.
-
-You also need to be careful that the tests are portable from one platform
-to another.  You're probably working on Linux, where the GNU toolchain has
-more (or different) functionality than on MacOS, *BSD, Solaris, AIX, etc.
-While testing on all platforms is the only sure-fire way to make sure that
-you've written portable code, here's a list of problems that have been
-found and fixed in the tests.  Another, more comprehensive list may be
-found in the GNU Autoconf manual, online here:
-
-    http://www.gnu.org/software/autoconf/manual/html_node/Portable-Shell.html
-
-sh:
-
-The Bourne shell is a very basic shell.  /bin/sh on Linux is typically
-bash, which even in Bourne-shell mode has many features that Bourne shells
-on other Unix systems don't have (and even on Linux /bin/sh isn't
-guaranteed to be bash).  You'll need to be careful about constructs that
-seem ubiquitous, but are actually not available in the least common
-denominator.  While using another shell (ksh, bash explicitly, posix shell,
-etc.) explicitly may seem like another option, these may not exist in a
-portable location, and so are generally probably not a good idea.  You may
-find that rewriting the test in python will be easier.
-
-- don't use pushd/popd; save the output of "pwd" and use "cd" in place of
-  the pushd, and cd back to the saved pwd instead of popd.
-
-- don't use math expressions like let, (( ... )), or $(( ... )); use "expr"
-  instead.
-
-grep:
-
-- don't use the -q option; redirect stdout to /dev/null instead.
-
-- don't use extended regular expressions with grep; use egrep instead, and
-  don't escape any regex operators.
-
-sed:
-
-- make sure that the beginning-of-line matcher ("^") is at the very
-  beginning of the expression -- it may not be supported inside parens.
-
-echo:
-
-- echo may interpret "\n" and print a newline; use printf instead if you
-  want a literal "\n" (backslash + n).
-
-false:
-
-- false is guaranteed only to return a non-zero value; you cannot depend on
-  it being 1.  On Solaris in particular, /bin/false returns 255.  Rewrite
-  your test to not depend on a particular return value, or create a
-  temporary "false" executable, and call that instead.
-
-diff:
-
-- don't use the -N option.  There's no particularly good workaround short
-  of writing a reasonably complicated replacement script, but substituting
-  gdiff for diff if you can't rewrite the test not to need -N will probably
-  do.
+See http://www.selenic.com/mercurial/wiki/index.cgi/WritingTests for
+more information on writing tests.