Add tests

tests/test_types.py

@@ -3936,6 +3936,45 @@ class Foobar(BaseModel):
     }
 
 
+@pytest.mark.parametrize(
+    'use_field',
+    [pytest.param(True, id='Field'), pytest.param(False, id='constr')],
+)
+def test_compiled_pattern_in_field(use_field):
+    """
+    https://github.com/pydantic/pydantic/issues/9052
+    https://github.com/pydantic/pydantic/pull/9053
+    """
+    pattern_value = r'^whatev.r\d$'
+    field_pattern = re.compile(pattern_value)
+
+    if use_field:
+
+        class Foobar(BaseModel):
+            str_regex: str = Field(..., pattern=field_pattern)
+    else:
+
+        class Foobar(BaseModel):
+            str_regex: constr(pattern=field_pattern) = ...
+
+    matching_value = 'whatever1'
+    f = Foobar(str_regex=matching_value)
+    assert f.str_regex == matching_value
+
+    with pytest.raises(
+        ValidationError,
+        match=re.escape("String should match pattern '" + pattern_value + "'"),
+    ):
+        Foobar(str_regex=' whatever1')
+
+    assert Foobar.model_json_schema() == {
+        'type': 'object',
+        'title': 'Foobar',
+        'properties': {'str_regex': {'pattern': pattern_value, 'title': 'Str Regex', 'type': 'string'}},
+        'required': ['str_regex'],
+    }
+
+
 def test_pattern_with_invalid_param():
     with pytest.raises(
         PydanticSchemaGenerationError,