Add assert_not_regex()

Closes: #10

Author: srittau

NEWS.md

@@ -4,6 +4,10 @@
 
 - Drop support for Python 3.6.
 
+### API Additions
+
+- Add `assert_not_regex()`.
+
 ### Other Changes
 
 - Modernize the type stubs.

asserts/__init__.py

@@ -551,6 +551,30 @@ def assert_regex(text, regex, msg_fmt="{msg}"):
         fail(msg_fmt.format(msg=msg, text=text, pattern=compiled.pattern))
 
 
+def assert_not_regex(text, regex, msg_fmt="{msg}"):
+    """Fail if text does match the regular expression.
+
+    regex can be either a regular expression string or a compiled regular
+    expression object.
+
+    >>> assert_regex("Hello World!", r"llo.*rld!$")
+    >>> assert_regex("Hello World!", r"\\d")
+    Traceback (most recent call last):
+        ...
+    AssertionError: 'Hello World!' does not match '\\\\d'
+
+    The following msg_fmt arguments are supported:
+    * msg - the default error message
+    * text - text that is matched
+    * pattern - regular expression pattern as string
+    """
+
+    compiled = re.compile(regex)
+    if compiled.search(text):
+        msg = "{!r} matches {!r}".format(text, compiled.pattern)
+        fail(msg_fmt.format(msg=msg, text=text, pattern=compiled.pattern))
+
+
 def assert_is(first, second, msg_fmt="{msg}"):
     """Fail if first and second do not refer to the same object.
 

asserts/__init__.pyi

@@ -104,6 +104,9 @@ def assert_greater_equal(
 def assert_regex(
     text: str, regex: str | Pattern[str], msg_fmt: str = ...
 ) -> None: ...
+def assert_not_regex(
+    text: str, regex: str | Pattern[str], msg_fmt: str = ...
+) -> None: ...
 def assert_is(first: object, second: object, msg_fmt: str = ...) -> None: ...
 def assert_is_not(
     first: object, second: object, msg_fmt: str = ...

test_asserts.py

@@ -5,46 +5,47 @@
 from collections import OrderedDict
 from datetime import datetime, timedelta
 from unittest import TestCase
-from warnings import warn, catch_warnings
+from warnings import catch_warnings, warn
 
 from asserts import (
-    fail,
-    assert_true,
-    assert_false,
-    assert_boolean_true,
-    assert_boolean_false,
-    assert_is_none,
-    assert_is_not_none,
-    assert_equal,
-    assert_not_equal,
+    Exists,
     assert_almost_equal,
-    assert_not_almost_equal,
+    assert_between,
+    assert_boolean_false,
+    assert_boolean_true,
+    assert_count_equal,
+    assert_datetime_about_now,
+    assert_datetime_about_now_utc,
     assert_dict_equal,
     assert_dict_superset,
-    assert_less,
-    assert_less_equal,
+    assert_equal,
+    assert_false,
     assert_greater,
     assert_greater_equal,
-    assert_between,
+    assert_has_attr,
+    assert_in,
     assert_is,
+    assert_is_instance,
+    assert_is_none,
     assert_is_not,
-    assert_in,
+    assert_is_not_none,
+    assert_json_subset,
+    assert_less,
+    assert_less_equal,
+    assert_not_almost_equal,
+    assert_not_equal,
     assert_not_in,
-    assert_count_equal,
-    assert_regex,
-    assert_is_instance,
     assert_not_is_instance,
-    assert_has_attr,
-    assert_datetime_about_now,
-    assert_datetime_about_now_utc,
+    assert_not_regex,
     assert_raises,
-    assert_raises_regex,
     assert_raises_errno,
+    assert_raises_regex,
+    assert_regex,
     assert_succeeds,
+    assert_true,
     assert_warns,
     assert_warns_regex,
-    assert_json_subset,
-    Exists,
+    fail,
 )
 
 
@@ -617,6 +618,49 @@ def test_assert_regex__does_not_match_regex__custom_message(self):
         ):
             assert_regex("Wrong text", regex, "{msg};{text!r};{pattern!r}")
 
+    # assert_not_regex()
+
+    def test_assert_not_regex__does_not_match_string(self):
+        assert_not_regex("This is a test text", "no match")
+
+    def test_assert_not_regex__does_not_match_regex(self):
+        regex = re.compile("no match")
+        assert_not_regex("This is a test text", regex)
+
+    def test_assert_not_regex__matches_string__default_message(self):
+        with _assert_raises_assertion(
+            "'This is a test text' matches 'is.*test'"
+        ):
+            assert_not_regex("This is a test text", "is.*test")
+
+    def test_assert_not_regex__matches_regex__default_message(self):
+        regex = re.compile("is.*test")
+        with _assert_raises_assertion(
+            "'This is a test text' matches 'is.*test'"
+        ):
+            assert_not_regex("This is a test text", regex)
+
+    def test_assert_not_regex__matches_string__custom_message(self):
+        with _assert_raises_assertion(
+            "'This is a test text' matches 'is.*test';"
+            "'This is a test text';'is.*test'"
+        ):
+            assert_not_regex(
+                "This is a test text",
+                "is.*test",
+                "{msg};{text!r};{pattern!r}",
+            )
+
+    def test_assert_not_regex__matches_regex__custom_message(self):
+        regex = re.compile("is.*test")
+        with _assert_raises_assertion(
+            "'This is a test text' matches 'is.*test';'This is a test text';"
+            "'is.*test'"
+        ):
+            assert_not_regex(
+                "This is a test text", regex, "{msg};{text!r};{pattern!r}"
+            )
+
     # assert_is()
 
     def test_assert_is__same(self):