Add contexts.describe() for debugging

mwparserfromhell/parser/contexts.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8  -*-
 #
-# Copyright (C) 2012-2017 Ben Kurtovic <ben.kurtovic@gmail.com>
+# Copyright (C) 2012-2019 Ben Kurtovic <ben.kurtovic@gmail.com>
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -193,3 +193,16 @@ UNSAFE = (TEMPLATE_NAME + WIKILINK_TITLE + EXT_LINK_TITLE +
 DOUBLE = TEMPLATE_PARAM_KEY + TAG_CLOSE + TABLE_ROW_OPEN
 NO_WIKILINKS = TEMPLATE_NAME + ARGUMENT_NAME + WIKILINK_TITLE + EXT_LINK_URI
 NO_EXT_LINKS = TEMPLATE_NAME + ARGUMENT_NAME + WIKILINK_TITLE + EXT_LINK
+
+def describe(context):
+    """Return a string describing the given context value, for debugging."""
+    flags = []
+    for name, value in globals().items():
+        if not isinstance(value, int) or name.startswith("GL_"):
+            continue
+        if bin(value).count("1") != 1:
+            continue  # Hacky way to skip aggregate contexts
+        if context & value:
+            flags.append((name, value))
+    flags.sort(key=lambda it: it[1])
+    return "|".join(it[0] for it in flags)

tests/test_pytokenizer.py

@@ -1,6 +1,6 @@
 # -*- coding: utf-8  -*-
 #
-# Copyright (C) 2012-2016 Ben Kurtovic <ben.kurtovic@gmail.com>
+# Copyright (C) 2012-2019 Ben Kurtovic <ben.kurtovic@gmail.com>
 #
 # Permission is hereby granted, free of charge, to any person obtaining a copy
 # of this software and associated documentation files (the "Software"), to deal
@@ -23,6 +23,7 @@
 from __future__ import unicode_literals
 import unittest
 
+from mwparserfromhell.parser import contexts
 from mwparserfromhell.parser.tokenizer import Tokenizer
 
 from ._test_tokenizer import TokenizerTestCase
@@ -40,5 +41,10 @@ class TestPyTokenizer(TokenizerTestCase, unittest.TestCase):
             self.assertFalse(Tokenizer.USES_C)
             self.assertFalse(Tokenizer().USES_C)
 
+    def test_describe_context(self):
+        self.assertEqual("", contexts.describe(0))
+        ctx = contexts.describe(contexts.TEMPLATE_PARAM_KEY|contexts.HAS_TEXT)
+        self.assertEqual("TEMPLATE_PARAM_KEY|HAS_TEXT", ctx)
+
 if __name__ == "__main__":
     unittest.main(verbosity=2)