Add extensible CLI commands (#853)

* Add extensible CLI commands * Handle plugin SystemExit failures
2026-08-16 16:10:25 +02:00 · 2026-08-05 23:30:28 +02:00
parent 93b7fb5232
commit 067f053627
7 changed files with 809 additions and 0 deletions
@@ -0,0 +1,371 @@
+from types import SimpleNamespace
+
+import click
+from click.testing import CliRunner
+
+from mvt.common.cli_plugins import (
+    ANDROID_CLI_PLUGIN_GROUP,
+    IOS_CLI_PLUGIN_GROUP,
+    BrokenPluginCommand,
+    load_cli_commands_option,
+    register_cli_commands_from_path,
+    register_cli_plugins,
+    register_installed_cli_commands,
+)
+
+
+COMMAND_TEMPLATE = """
+import click
+
+
+@click.command({name!r})
+@click.pass_context
+def cli(ctx):
+    click.echo({message!r})
+    if ctx.obj:
+        click.echo(ctx.obj.get("marker", ""))
+"""
+
+
+def _write_command(path, name, message="command ran"):
+    path.write_text(
+        COMMAND_TEMPLATE.format(name=name, message=message),
+        encoding="utf-8",
+    )
+    return path
+
+
+def _make_group():
+    @click.group()
+    @load_cli_commands_option
+    @click.pass_context
+    def group(ctx):
+        ctx.ensure_object(dict)
+        ctx.obj["marker"] = "parent context"
+
+    return group
+
+
+def _entry_point(name, value, command=None, exception=None, distribution="plugin"):
+    def load():
+        if exception is not None:
+            raise exception
+        return command
+
+    dist = SimpleNamespace(metadata={"Name": distribution}, version="1.0")
+    return SimpleNamespace(name=name, value=value, load=load, dist=dist)
+
+
+def test_load_command_option_registers_command_before_resolution(tmp_path):
+    command_path = _write_command(tmp_path / "hello.py", "hello")
+    group = _make_group()
+
+    result = CliRunner().invoke(
+        group,
+        ["--load-command", str(command_path), "hello"],
+    )
+
+    assert result.exit_code == 0
+    assert "command ran" in result.output
+    assert "parent context" in result.output
+
+
+def test_load_command_option_supports_folders_and_repeated_paths(tmp_path):
+    folder = tmp_path / "commands"
+    folder.mkdir()
+    _write_command(folder / "b.py", "second")
+    _write_command(folder / "a.py", "first")
+    _write_command(folder / ".hidden.py", "hidden")
+    _write_command(folder / "__init__.py", "init")
+    other = _write_command(tmp_path / "third.py", "third")
+    group = _make_group()
+
+    result = CliRunner().invoke(
+        group,
+        [
+            "--load-command",
+            str(folder),
+            "--load-command",
+            str(other),
+            "--load-command",
+            str(other),
+            "--help",
+        ],
+    )
+
+    assert result.exit_code == 0
+    assert "first" in result.output
+    assert "second" in result.output
+    assert "third" in result.output
+    assert "hidden" not in result.output
+    assert "init" not in result.output
+
+
+def test_loaded_command_participates_in_shell_completion(tmp_path):
+    command_path = _write_command(tmp_path / "hello.py", "hello")
+    group = _make_group()
+    words = f"group --load-command {command_path} he"
+
+    result = CliRunner().invoke(
+        group,
+        [],
+        env={
+            "_GROUP_COMPLETE": "bash_complete",
+            "COMP_WORDS": words,
+            "COMP_CWORD": "3",
+        },
+    )
+
+    assert result.exit_code == 0
+    assert "plain,hello" in result.output
+
+
+def test_explicit_command_import_and_contract_failures_are_usage_errors(tmp_path):
+    broken_path = tmp_path / "broken.py"
+    broken_path.write_text("raise RuntimeError('broken import')", encoding="utf-8")
+    missing_cli_path = tmp_path / "missing_cli.py"
+    missing_cli_path.write_text("value = 1", encoding="utf-8")
+
+    broken_result = CliRunner().invoke(
+        _make_group(),
+        ["--load-command", str(broken_path), "broken"],
+    )
+    missing_cli_result = CliRunner().invoke(
+        _make_group(),
+        ["--load-command", str(missing_cli_path), "missing-cli"],
+    )
+
+    assert broken_result.exit_code == 2
+    assert "broken import" in broken_result.output
+    assert missing_cli_result.exit_code == 2
+    assert "must export a Click command or group named 'cli'" in (
+        missing_cli_result.output
+    )
+
+
+def test_environment_command_failure_gets_broken_placeholder(tmp_path):
+    command_path = tmp_path / "broken_command.py"
+    command_path.write_text("raise RuntimeError('broken import')", encoding="utf-8")
+    group = click.Group()
+
+    registered = register_cli_commands_from_path(group, command_path)
+
+    assert registered == ["broken-command"]
+    assert isinstance(group.commands["broken-command"], BrokenPluginCommand)
+    result = CliRunner().invoke(group, ["broken-command"])
+    assert result.exit_code == 1
+    assert "broken import" in result.output
+    assert str(command_path) in result.output
+
+
+def test_environment_command_system_exit_gets_broken_placeholder(tmp_path):
+    command_path = tmp_path / "exiting_command.py"
+    command_path.write_text("raise SystemExit(7)", encoding="utf-8")
+    group = click.Group()
+
+    registered = register_cli_commands_from_path(group, command_path)
+
+    assert registered == ["exiting-command"]
+    assert isinstance(group.commands["exiting-command"], BrokenPluginCommand)
+    result = CliRunner().invoke(group, ["exiting-command"])
+    assert result.exit_code == 1
+    assert "Unable to import custom command" in result.output
+    assert result.output.rstrip().endswith(": 7")
+
+
+def test_installed_entry_point_name_is_the_command_name(monkeypatch):
+    @click.command("internal-name")
+    def command():
+        click.echo("installed command ran")
+
+    entry_point = _entry_point(
+        "external-name",
+        "example_plugin:cli",
+        command=command,
+    )
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        lambda **kwargs: [entry_point],
+    )
+    group = click.Group()
+
+    registered = register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    assert registered == ["external-name"]
+    assert "internal-name" not in group.commands
+    result = CliRunner().invoke(group, ["external-name"])
+    assert result.exit_code == 0
+    assert result.output == "installed command ran\n"
+
+
+def test_broken_installed_plugin_does_not_break_cli(monkeypatch):
+    broken = _entry_point(
+        "broken",
+        "broken_plugin:cli",
+        exception=RuntimeError("missing dependency"),
+        distribution="broken-plugin",
+    )
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        lambda **kwargs: [broken],
+    )
+    group = click.Group()
+
+    register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    help_result = CliRunner().invoke(group, ["--help"])
+    assert help_result.exit_code == 0
+    assert "Warning: external command could not be loaded." in help_result.output
+
+    result = CliRunner().invoke(group, ["broken"])
+    assert result.exit_code == 1
+    assert "broken-plugin 1.0 (broken_plugin:cli)" in result.output
+    assert "RuntimeError: missing dependency" in result.output
+
+
+def test_installed_plugin_system_exit_does_not_break_cli(monkeypatch):
+    exiting = _entry_point(
+        "exiting",
+        "exiting_plugin:cli",
+        exception=SystemExit(7),
+        distribution="exiting-plugin",
+    )
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        lambda **kwargs: [exiting],
+    )
+    group = click.Group()
+
+    register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    help_result = CliRunner().invoke(group, ["--help"])
+    assert help_result.exit_code == 0
+    result = CliRunner().invoke(group, ["exiting"])
+    assert result.exit_code == 1
+    assert "SystemExit: 7" in result.output
+
+
+def test_non_click_entry_point_gets_broken_placeholder(monkeypatch):
+    invalid = _entry_point("invalid", "plugin:value", command=object())
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        lambda **kwargs: [invalid],
+    )
+    group = click.Group()
+
+    register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    assert isinstance(group.commands["invalid"], BrokenPluginCommand)
+    result = CliRunner().invoke(group, ["invalid"])
+    assert result.exit_code == 1
+    assert "must resolve to a Click command or group" in result.output
+
+
+def test_entry_point_discovery_failure_does_not_break_group(monkeypatch, caplog):
+    def fail_discovery(**kwargs):
+        raise RuntimeError("invalid package metadata")
+
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        fail_discovery,
+    )
+    group = click.Group()
+
+    registered = register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    assert registered == []
+    assert not group.commands
+    assert "Unable to discover external commands" in caplog.text
+    assert "invalid package metadata" in caplog.text
+
+
+def test_builtin_and_first_external_command_win_collisions(monkeypatch, caplog):
+    @click.command("version")
+    def core_version():
+        pass
+
+    @click.command()
+    def first():
+        pass
+
+    @click.command()
+    def second():
+        pass
+
+    entry_points = [
+        _entry_point("duplicate", "z_plugin:cli", command=second, distribution="z"),
+        _entry_point("version", "plugin:version", command=first),
+        _entry_point("duplicate", "a_plugin:cli", command=first, distribution="a"),
+    ]
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        lambda **kwargs: entry_points,
+    )
+    group = click.Group(commands={"version": core_version})
+
+    registered = register_installed_cli_commands(group, IOS_CLI_PLUGIN_GROUP)
+
+    assert registered == ["duplicate"]
+    assert group.commands["version"] is core_version
+    assert group.commands["duplicate"] is first
+    assert "the command name is already registered" in caplog.text
+
+
+def test_explicit_command_cannot_replace_existing_command(tmp_path):
+    command_path = _write_command(tmp_path / "version.py", "version")
+    group = _make_group()
+
+    @group.command("version")
+    def core_version():
+        pass
+
+    result = CliRunner().invoke(
+        group,
+        ["--load-command", str(command_path), "version"],
+    )
+
+    assert result.exit_code == 2
+    assert "the command name is already registered" in result.output
+
+
+def test_platform_entry_point_groups_and_environment_paths_are_separate(
+    tmp_path, monkeypatch
+):
+    ios_path = _write_command(tmp_path / "ios.py", "ios-file")
+    android_path = _write_command(tmp_path / "android.py", "android-file")
+
+    @click.command()
+    def ios_package():
+        pass
+
+    @click.command()
+    def android_package():
+        pass
+
+    def entry_points(*, group):
+        if group == IOS_CLI_PLUGIN_GROUP:
+            return [_entry_point("ios-package", "ios_plugin:cli", ios_package)]
+        return [_entry_point("android-package", "android_plugin:cli", android_package)]
+
+    monkeypatch.setattr(
+        "mvt.common.cli_plugins.importlib.metadata.entry_points",
+        entry_points,
+    )
+    monkeypatch.setenv("TEST_IOS_COMMANDS", str(ios_path))
+    monkeypatch.setenv("TEST_ANDROID_COMMANDS", str(android_path))
+    ios_group = click.Group()
+    android_group = click.Group()
+
+    register_cli_plugins(
+        ios_group,
+        entry_point_group=IOS_CLI_PLUGIN_GROUP,
+        environment_variable="TEST_IOS_COMMANDS",
+    )
+    register_cli_plugins(
+        android_group,
+        entry_point_group=ANDROID_CLI_PLUGIN_GROUP,
+        environment_variable="TEST_ANDROID_COMMANDS",
+    )
+
+    assert set(ios_group.commands) == {"ios-file", "ios-package"}
+    assert set(android_group.commands) == {"android-file", "android-package"}