Add with_case_tags decorator

docs/api_reference.md

@@ -197,6 +197,57 @@ Returns True if the provided object is a function or callable and, if `check_pre
 
  - `check_prefix`: if this boolean is True (default), the prefix will be checked. If False, any function will lead to a `True` result whatever its name.
 
+
+### `@with_case_tags`
+
+```python
+@with_case_tags(*tags,  # type: Any
+                ):
+```
+
+This decorator can be applied to a class defining cases to apply multiple
+`*tags` to all case methods defined thereby.
+
+```python
+@with_case_tags('tag_1', 'tag_2')
+class CasesContainerClass:
+
+    def case_one(self, ...):
+        ...
+
+    @case(tags='another_tag')
+    def case_two(self, ...):
+        ...
+
+    @case(tags='tag_1')
+    def case_three(self, ...):
+        ...
+```
+
+This is equivalent to:
+
+
+```python
+class CasesContainerClass:
+
+    @case(tags=('tag_1', 'tag_2'))
+    def case_one(self, ...):
+        ...
+
+    @case(tags=('another_tag', 'tag_1', 'tag_2'))
+    def case_two(self, ...):
+        ...
+
+    @case(tags=('tag_1', 'tag_2'))
+    def case_three(self, ...):
+        ...
+```
+
+**Parameters:**
+
+ - `tags`: custom tags to be added to all case methods. See also [`@case(tags=...)`](#case).
+
+
 ### The `filters` submodule
 
 This submodule contains symbols to help you create filters for `@parametrize_with_cases(filter=...)`.

docs/changelog.md

@@ -1,5 +1,11 @@
 # Changelog
 
+### 3.8.6 - Add with_case_tags decorator
+- Added the `with_case_tags` decorator for applying common tags to all cases
+  defined in a case class. Fixes [#351](https://github.com/smarie/python-pytest-cases/issues/351).
+  PR [#361](https://github.com/smarie/python-pytest-cases/issues/361)
+  by [@michele-riva](https://github.com/michele-riva).
+
 ### 3.8.6 - compatibility fix
 
 - Fixed issue with legacy python 2.7 and 3.5. Fixes [#352](https://github.com/smarie/python-pytest-cases/issues/352).

docs/index.md

@@ -269,7 +269,7 @@ def test_bad_datasets(data, err_type, err_msg):
 ``` 
 
 
- - the `has_tag` argument allows you to filter cases based on tags set on case functions using the `@case` decorator. See API reference of [`@case`](./api_reference.md#case) and [`@parametrize_with_cases`](./api_reference.md#parametrize_with_cases).
+ - the `has_tag` argument allows you to filter cases based on tags set on case functions using the `@case` decorator. See API reference of [`@case`](./api_reference.md#case) and [`@parametrize_with_cases`](./api_reference.md#parametrize_with_cases). Tags shared by multiple cases grouped inside a class may be added automatically to all cases using the [`@with_case_tags`](./api_reference.md#with_case_tags) decorator.
 
 
 ```python

src/pytest_cases/__init__.py

@@ -10,7 +10,7 @@
 from .fixture_parametrize_plus import pytest_parametrize_plus, parametrize_plus, parametrize, fixture_ref
 
 from .case_funcs import case, copy_case_info, set_case_id, get_case_id, get_case_marks, \
-    get_case_tags, matches_tag_query, is_case_class, is_case_function
+    get_case_tags, matches_tag_query, is_case_class, is_case_function, with_case_tags
 from .case_parametrizer_new import parametrize_with_cases, THIS_MODULE, get_all_cases, get_parametrize_args, \
     get_current_case_id, get_current_cases, get_current_params, CasesCollectionWarning
 

src/pytest_cases/case_funcs.py

@@ -366,3 +366,30 @@ def is_case_function(f,                       # type: Any
         except:
             # GH#287: safe fallback
             return False
+
+
+def with_case_tags(*tags):
+    """Attach `tags` to all cases defined in the decorated class."""
+    def _decorator(cls):
+        if is_case_function(cls):
+            raise ValueError(
+                'Cannot use with_case_tags on a case '
+                'function. Use the @case decorator instead.'
+                )
+        if not is_case_class(cls):
+            raise ValueError('with_case_tags can only be applied to classes '
+                             'defining a collection of cases.')
+        for case_name in dir(cls):
+            case_ = getattr(cls, case_name)
+            if not is_case_function(case_):  # Not a case
+                continue
+            try:
+                case_info = getattr(case_, CASE_FIELD)
+            except AttributeError:
+                # Not explicitly decorated with @case. Do so now.
+                case_ = case(case_)
+                case_info = getattr(case_, CASE_FIELD)
+            tags_to_add = tuple(t for t in tags if t not in case_info.tags)
+            case_info.add_tags(tags_to_add)
+        return cls
+    return _decorator