cli: add self show command

src/poetry/console/application.py

@@ -87,6 +87,7 @@ COMMANDS = [
     "self install",
     "self remove",
     "self update",
+    "self show",
     # Source commands
     "source add",
     "source remove",

src/poetry/console/commands/group_command.py

@@ -85,7 +85,7 @@ class GroupCommand(EnvCommand):
         for key in {"with", "without", "only"}:
             groups[key] = {
                 group.strip()
-                for groups in self.option(key)
+                for groups in self.option(key, "")
                 for group in groups.split(",")
             }
 

src/poetry/console/commands/self/show/__init__.py

+from __future__ import annotations
+
+from cleo.helpers import option
+
+from poetry.console.commands.self.self_command import SelfCommand
+from poetry.console.commands.show import ShowCommand
+
+
+class SelfShowCommand(SelfCommand, ShowCommand):
+    name = "self show"
+    options = [
+        option("addons", None, "List only add-on packages installed."),
+        *[o for o in ShowCommand.options if o.name in {"tree", "latest", "outdated"}],
+    ]
+    description = "Show packages from Poetry's runtime environment."
+    help = f"""\
+The <c1>self show</c1> command behaves similar to the <c1>show</c1> command, but
+working within Poetry's runtime environment. This lists all packages installed within
+the Poetry install environment.
+
+To show only additional packages that have been added via <c1>self add</c1> and their
+dependencies use <c1>self show --addons</c1>.
+
+This is managed in the <comment>{SelfCommand.get_default_system_pyproject_file()}</> \
+file.
+"""
+
+    @property
+    def activated_groups(self) -> set[str]:
+        if self.option("addons", False):
+            return {SelfCommand.ADDITIONAL_PACKAGE_GROUP}
+
+        return super(ShowCommand, self).activated_groups