irc: test sopel.irc.utils.safe function

sopel/irc/utils.py

@@ -35,7 +35,30 @@ def get_cnames(domain):
 
 
 def safe(string):
-    """Remove newlines from a string."""
+    """Remove newlines from a string.
+
+    :param str string: input text to process
+    :return: the string without newlines
+    :rtype: str
+    :raises TypeError: when ``string`` is ``None``
+
+    This function removes newlines from a string and always returns a unicode
+    string (as in ``str`` on Python 3 and ``unicode`` on Python 2), but doesn't
+    strip or alter it in any other way::
+
+        >>> safe('some text\\r\\n')
+        'some text'
+
+    This is useful to ensure a string can be used in a IRC message.
+
+    .. versionchanged:: 7.1
+
+        This function now raises a :exc:`TypeError` instead of an unpredictable
+        behaviour when given ``None``.
+
+    """
+    if string is None:
+        raise TypeError('safe function requires a string, not NoneType')
     if sys.version_info.major >= 3 and isinstance(string, bytes):
         string = string.decode("utf8")
     elif sys.version_info.major < 3:

test/irc/test_irc_utils.py

@@ -0,0 +1,44 @@
+# coding=utf-8
+"""Tests for core ``sopel.irc.utils``"""
+from __future__ import absolute_import, division, print_function, unicode_literals
+
+import pytest
+
+from sopel.irc import utils
+
+
+def test_safe():
+    text = 'some text'
+    assert utils.safe(text + '\r\n') == text
+    assert utils.safe(text + '\n') == text
+    assert utils.safe(text + '\r') == text
+    assert utils.safe('\r\n' + text) == text
+    assert utils.safe('\n' + text) == text
+    assert utils.safe('\r' + text) == text
+    assert utils.safe('some \r\ntext') == text
+    assert utils.safe('some \ntext') == text
+    assert utils.safe('some \rtext') == text
+
+
+def test_safe_empty():
+    text = ''
+    assert utils.safe(text) == text
+
+
+def test_safe_null():
+    with pytest.raises(TypeError):
+        utils.safe(None)
+
+
+def test_safe_bytes():
+    text = b'some text'
+    assert utils.safe(text) == text.decode('utf-8')
+    assert utils.safe(text + b'\r\n') == text.decode('utf-8')
+    assert utils.safe(text + b'\n') == text.decode('utf-8')
+    assert utils.safe(text + b'\r') == text.decode('utf-8')
+    assert utils.safe(b'\r\n' + text) == text.decode('utf-8')
+    assert utils.safe(b'\n' + text) == text.decode('utf-8')
+    assert utils.safe(b'\r' + text) == text.decode('utf-8')
+    assert utils.safe(b'some \r\ntext') == text.decode('utf-8')
+    assert utils.safe(b'some \ntext') == text.decode('utf-8')
+    assert utils.safe(b'some \rtext') == text.decode('utf-8')