Allow users to provide version information to the required_plugins INI key

changelog/7346.feature.rst

@@ -0,0 +1 @@
+Version information as defined by `PEP 440 <https://www.python.org/dev/peps/pep-0440/#version-specifiers>`_ may now be included when providing plugins to the ``required_plugins`` configuration option.

doc/en/reference.rst

@@ -1562,12 +1562,14 @@ passed multiple times. The expected format is ``name=value``. For example::
 .. confval:: required_plugins
 
    A space separated list of plugins that must be present for pytest to run.
+   Plugins can be listed with or without version specifiers directly following
+   their name. Whitespace between different version specifiers is not allowed.
    If any one of the plugins is not found, emit an error.
 
    .. code-block:: ini
 
        [pytest]
-       required_plugins = pytest-html pytest-xdist
+       required_plugins = pytest-django>=3.0.0,<4.0.0 pytest-html pytest-xdist>=1.0.0
 
 
 .. confval:: testpaths

src/_pytest/config/__init__.py

@@ -1094,13 +1094,26 @@ def _validate_plugins(self) -> None:
         if not required_plugins:
             return
 
+        # Imported lazily to improve start-up time.
+        from packaging.version import Version
+        from packaging.requirements import InvalidRequirement, Requirement
+
         plugin_info = self.pluginmanager.list_plugin_distinfo()
-        plugin_dist_names = [dist.project_name for _, dist in plugin_info]
+        plugin_dist_info = {dist.project_name: dist.version for _, dist in plugin_info}
 
         missing_plugins = []
-        for plugin in required_plugins:
-            if plugin not in plugin_dist_names:
-                missing_plugins.append(plugin)
+        for required_plugin in required_plugins:
+            spec = None
+            try:
+                spec = Requirement(required_plugin)
+            except InvalidRequirement:
+                missing_plugins.append(required_plugin)
+                continue
+
+            if spec.name not in plugin_dist_info:
+                missing_plugins.append(required_plugin)
+            elif Version(plugin_dist_info[spec.name]) not in spec.specifier:
+                missing_plugins.append(required_plugin)
 
         if missing_plugins:
             fail(

testing/test_config.py

@@ -250,6 +250,63 @@ def test_invalid_ini_keys(
             ),
             (
                 """
+          [pytest]
+          required_plugins = pytest-xdist
+          """,
+                "",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist==1.32.0
+          """,
+                "",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist>1.0.0,<2.0.0
+          """,
+                "",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist~=1.32.0 pytest-xdist==1.32.0 pytest-xdist!=0.0.1 pytest-xdist<=99.99.0
+            pytest-xdist>=1.32.0 pytest-xdist<9.9.9 pytest-xdist>1.30.0 pytest-xdist===1.32.0
+          """,
+                "",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist>9.9.9 pytest-xdist==1.32.0 pytest-xdist==8.8.8
+          """,
+                "Missing required plugins: pytest-xdist==8.8.8, pytest-xdist>9.9.9",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist==aegsrgrsgs pytest-xdist==-1 pytest-xdist>2.1.1,>3.0.0
+          """,
+                "Missing required plugins: pytest-xdist==-1, pytest-xdist==aegsrgrsgs, pytest-xdist>2.1.1,>3.0.0",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist== pytest-xdist<=
+          """,
+                "Missing required plugins: pytest-xdist<=, pytest-xdist==",
+            ),
+            (
+                """
+          [pytest]
+          required_plugins = pytest-xdist= pytest-xdist<
+          """,
+                "Missing required plugins: pytest-xdist<, pytest-xdist=",
+            ),
+            (
+                """
           [some_other_header]
           required_plugins = wont be triggered
           [pytest]