hgweb: add .jshintrc with some basic rules

This file is picked up automatically by jshint, so no extra changes required in
test-check-jshint.t.

.jshintrc

@@ -0,0 +1,11 b''
+{
+    // Enforcing
+    "eqeqeq"        : true,     // true: Require triple equals (===) for comparison
+    "forin"         : true,     // true: Require filtering for..in loops with obj.hasOwnProperty()
+    "freeze"        : true,     // true: prohibits overwriting prototypes of native objects such as Array, Date etc.
+    "nonbsp"        : true,     // true: Prohibit "non-breaking whitespace" characters.
+    "undef"         : true,     // true: Require all non-global variables to be declared (prevents global leaks)
+
+    // Environments
+    "browser"       : true      // Web Browser (window, document, etc)
+}

tests/test-check-code.t

@@ -1,55 +1,56 b''
 #require test-repo
 
   $ . "$TESTDIR/helpers-testrepo.sh"
   $ check_code="$TESTDIR"/../contrib/check-code.py
   $ cd "$TESTDIR"/..
 
 New errors are not allowed. Warnings are strongly discouraged.
 (The writing "no-che?k-code" is for not skipping this file when checking.)
 
   $ testrepohg locate \
   > -X contrib/python-zstandard \
   > -X hgext/fsmonitor/pywatchman \
   > -X mercurial/thirdparty \
   > | sed 's-\\-/-g' | "$check_code" --warnings --per-file=0 - || false
   Skipping i18n/polib.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/__init__.py it has no-che?k-code (glob)
   Skipping mercurial/httpclient/_readers.py it has no-che?k-code (glob)
   Skipping mercurial/selectors2.py it has no-che?k-code (glob)
   Skipping mercurial/statprof.py it has no-che?k-code (glob)
   Skipping tests/badserverext.py it has no-che?k-code (glob)
 
 @commands in debugcommands.py should be in alphabetical order.
 
   >>> import re
   >>> commands = []
   >>> with open('mercurial/debugcommands.py', 'rb') as fh:
   ...     for line in fh:
   ...         m = re.match("^@command\('([a-z]+)", line)
   ...         if m:
   ...             commands.append(m.group(1))
   >>> scommands = list(sorted(commands))
   >>> for i, command in enumerate(scommands):
   ...     if command != commands[i]:
   ...         print('commands in debugcommands.py not sorted; first differing '
   ...               'command is %s; expected %s' % (commands[i], command))
   ...         break
 
 Prevent adding new files in the root directory accidentally.
 
   $ testrepohg files 'glob:*'
   .arcconfig
   .clang-format
   .editorconfig
   .hgignore
   .hgsigs
   .hgtags
+  .jshintrc
   CONTRIBUTING
   CONTRIBUTORS
   COPYING
   Makefile
   README.rst
   hg
   hgeditor
   hgweb.cgi
   setup.py