linter: Add rule against verbose $(document).ready() calls.

docs/code-style.md

@@ -261,15 +261,7 @@ parenthesis for the outer call are together on the same line. This style
 isn't necessarily appropriate for calls with multiple anonymous
 functions or other arguments following them.
 
-Use
-
-    $(function () { ...
-
-rather than
-
-    $(document).ready(function () { ...
-
-and combine adjacent on-ready functions, if they are logically related.
+Combine adjacent on-ready functions, if they are logically related.
 
 The best way to build complicated DOM elements is a Mustache template
 like `static/templates/message_reactions.handlebars`. For simpler things

tools/linter_lib/custom_check.py

@@ -187,6 +187,10 @@ def build_custom_checkers(by_lang):
         {'pattern': 'report.error\(["\']',
          'description': 'Argument to report_error should be a literal string enclosed '
                         'by i18n.t()'},
+        {'pattern': '\$\(document\)\.ready\(',
+         'description': "`Use $(f) rather than `$(document).ready(f)`",
+         'good_lines': ['$(function () {foo();}'],
+         'bad_lines': ['$(document).ready(function () {foo();}']},
     ]) + whitespace_rules
     python_rules = cast(RuleList, [
         {'pattern': '^(?!#)@login_required',