llm plugins --hook X option, closes #1047

docs/help.md

@@ -811,8 +811,9 @@ Usage: llm plugins [OPTIONS]
   List installed plugins
 
 Options:
-  --all   Include built-in default plugins
-  --help  Show this message and exit.
+  --all        Include built-in default plugins
+  --hook TEXT  Filter for plugins that implement this hook
+  --help       Show this message and exit.
 ```
 
 (help-install)=

llm/cli.py

@@ -2617,9 +2617,16 @@ def fragments_loaders():
 
 @cli.command(name="plugins")
 @click.option("--all", help="Include built-in default plugins", is_flag=True)
-def plugins_list(all):
+@click.option(
+    "hooks", "--hook", help="Filter for plugins that implement this hook", multiple=True
+)
+def plugins_list(all, hooks):
     "List installed plugins"
-    click.echo(json.dumps(get_plugins(all), indent=2))
+    plugins = get_plugins(all)
+    hooks = set(hooks)
+    if hooks:
+        plugins = [plugin for plugin in plugins if hooks.intersection(plugin["hooks"])]
+    click.echo(json.dumps(plugins, indent=2))
 
 
 def display_truncated(text):

tests/test_plugins.py

@@ -290,3 +290,25 @@ def test_register_tools(tmpdir):
     finally:
         plugins.pm.unregister(name="ToolsPlugin")
         assert llm.get_tools() == {}
+
+
+def test_plugins_command():
+    runner = CliRunner()
+    result = runner.invoke(cli.cli, ["plugins"])
+    assert result.exit_code == 0
+    assert json.loads(result.output) == [
+        {"name": "EchoModelPlugin", "hooks": ["register_models"]},
+        {
+            "name": "MockModelsPlugin",
+            "hooks": ["register_embedding_models", "register_models"],
+        },
+    ]
+    # Test the --hook option
+    result2 = runner.invoke(cli.cli, ["plugins", "--hook", "register_embedding_models"])
+    assert result2.exit_code == 0
+    assert json.loads(result2.output) == [
+        {
+            "name": "MockModelsPlugin",
+            "hooks": ["register_embedding_models", "register_models"],
+        },
+    ]