Add option to allow installing deps from custom Poetry groups

tox_poetry_installer/hooks.py

@@ -4,6 +4,7 @@ All implementations of tox hooks are defined here, as well as any single-use hel
 specifically related to implementing the hooks (to keep the size/readability of the hook functions
 themselves manageable).
 """
+from itertools import chain
 from typing import Optional
 
 import tox
@@ -117,6 +118,13 @@ def tox_addoption(parser: ToxParser):
         help="Automatically install all Poetry development dependencies to the environment",
     )
 
+    parser.add_testenv_attribute(
+        name="poetry_dep_groups",
+        type="line-list",
+        default=[],
+        help="List of Poetry dependency groups to install to the environment",
+    )
+
     parser.add_testenv_attribute(
         name="install_project_deps",
         type="string",
@@ -196,6 +204,20 @@ def tox_testenv_install_deps(venv: ToxVirtualEnv, action: ToxAction) -> Optional
             dev_deps = []
             logger.info("Env does not install development dependencies, skipping")
 
+        group_deps = utilities.dedupe_packages(
+            list(
+                chain(
+                    *[
+                        utilities.find_group_deps(group, packages, virtualenv, poetry)
+                        for group in venv.envconfig.poetry_dep_groups
+                    ]
+                )
+            )
+        )
+        logger.info(
+            f"Identified {len(group_deps)} group dependencies to install to env"
+        )
+
         env_deps = utilities.find_additional_deps(
             packages, virtualenv, poetry, venv.envconfig.locked_deps
         )
@@ -231,7 +253,9 @@ def tox_testenv_install_deps(venv: ToxVirtualEnv, action: ToxAction) -> Optional
         logger.error(f"Internal plugin error: {err}")
         raise err
 
-    dependencies = utilities.dedupe_packages(dev_deps + env_deps + project_deps)
+    dependencies = utilities.dedupe_packages(
+        dev_deps + group_deps + env_deps + project_deps
+    )
     if (
         venv.envconfig.config.option.parallel_install_threads
         != constants.DEFAULT_INSTALL_THREADS

tox_poetry_installer/utilities.py

@@ -246,6 +246,33 @@ def find_additional_deps(
     return dedupe_packages(dependencies)
 
 
+def find_group_deps(
+    group: str,
+    packages: PackageMap,
+    venv: "_poetry.VirtualEnv",
+    poetry: "_poetry.Poetry",
+) -> List[PoetryPackage]:
+    """Find the dependencies belonging to a dependency group
+
+    Recursively identify the Poetry dev dependencies
+
+    :param group: Name of the dependency group from the project's ``pyproject.toml``
+    :param packages: Mapping of all locked package names to their corresponding package object
+    :param venv: Poetry virtual environment to use for package compatibility checks
+    :param poetry: Poetry object for the current project
+    """
+    return find_additional_deps(
+        packages,
+        venv,
+        poetry,
+        poetry.pyproject.data["tool"]["poetry"]
+        .get("group", {})
+        .get(group, {})
+        .get("dependencies", {})
+        .keys(),
+    )
+
+
 def find_dev_deps(
     packages: PackageMap, venv: "_poetry.VirtualEnv", poetry: "_poetry.Poetry"
 ) -> List[PoetryPackage]:
@@ -257,16 +284,7 @@ def find_dev_deps(
     :param venv: Poetry virtual environment to use for package compatibility checks
     :param poetry: Poetry object for the current project
     """
-    dev_group_deps = find_additional_deps(
-        packages,
-        venv,
-        poetry,
-        poetry.pyproject.data["tool"]["poetry"]
-        .get("group", {})
-        .get("dev", {})
-        .get("dependencies", {})
-        .keys(),
-    )
+    dev_group_deps = find_group_deps("dev", packages, venv, poetry)
 
     # Legacy pyproject.toml poetry format:
     legacy_dev_group_deps = find_additional_deps(