feat(cli): add --migration option to config command

src/poetry/console/commands/config.py

@@ -16,6 +16,8 @@
 from poetry.config.config import boolean_normalizer
 from poetry.config.config import boolean_validator
 from poetry.config.config import int_normalizer
+from poetry.config.config_source import UNSET
+from poetry.config.config_source import ConfigSourceMigration
 from poetry.console.commands.command import Command
 
 
@@ -25,6 +27,17 @@
 
     from poetry.config.config_source import ConfigSource
 
+CONFIG_MIGRATIONS = [
+    ConfigSourceMigration(
+        old_key="experimental.system-git-client", new_key="system-git-client"
+    ),
+    ConfigSourceMigration(
+        old_key="virtualenvs.prefer-active-python",
+        new_key="virtualenvs.use-poetry-python",
+        value_migration={True: UNSET, False: True},
+    ),
+]
+
 
 class ConfigCommand(Command):
     name = "config"
@@ -39,6 +52,7 @@ class ConfigCommand(Command):
         option("list", None, "List configuration settings."),
         option("unset", None, "Unset configuration setting."),
         option("local", None, "Set/Get from the project's local configuration."),
+        option("migrate", None, "Migrate outdated configuration settings."),
     ]
 
     help = """\
@@ -97,6 +111,9 @@ def handle(self) -> int:
         from poetry.locations import CONFIG_DIR
         from poetry.toml.file import TOMLFile
 
+        if self.option("migrate"):
+            self._migrate()
+
         config = Config.create()
         config_file = TOMLFile(CONFIG_DIR / "config.toml")
 
@@ -324,3 +341,14 @@ def _list_configuration(
                 message = f"<c1>{k + key}</c1> = <c2>{json.dumps(value)}</c2>"
 
             self.line(message)
+
+    def _migrate(self) -> None:
+        from poetry.config.file_config_source import FileConfigSource
+        from poetry.locations import CONFIG_DIR
+        from poetry.toml.file import TOMLFile
+
+        config_file = TOMLFile(CONFIG_DIR / "config.toml")
+        config_source = FileConfigSource(config_file)
+
+        for migration in CONFIG_MIGRATIONS:
+            migration.apply(config_source)

tests/console/commands/test_config.py

@@ -2,7 +2,9 @@
 
 import json
 import os
+import textwrap
 
+from pathlib import Path
 from typing import TYPE_CHECKING
 
 import pytest
@@ -18,8 +20,6 @@
 
 
 if TYPE_CHECKING:
-    from pathlib import Path
-
     from cleo.testers.command_tester import CommandTester
     from pytest_mock import MockerFixture
 
@@ -560,3 +560,33 @@ def test_config_solver_lazy_wheel(
 
     repo = LegacyRepository("foo", "https://foo.com")
     assert not repo._lazy_wheel
+
+
+def test_config_migrate(
+    tester: CommandTester, mocker: MockerFixture, tmp_path: Path
+) -> None:
+    config_dir = tmp_path / "config"
+    mocker.patch("poetry.locations.CONFIG_DIR", config_dir)
+
+    config_file = Path(config_dir / "config.toml")
+    config_data = textwrap.dedent("""\
+    [experimental]
+    system-git-client = true
+
+    [virtualenvs]
+    prefer-active-python = false
+    """)
+    with config_file.open("w") as fh:
+        fh.write(config_data)
+
+    tester.execute("--migrate")
+
+    expected_config = textwrap.dedent("""\
+    system-git-client = true
+
+    [virtualenvs]
+    use-poetry-python = true
+    """)
+
+    with config_file.open("r") as fh:
+        assert fh.read() == expected_config