minimal plugin system ideas (#24)

* add pluggy dependency

* move imports out of cli and add initialy pluggy init calls

* add cmd pluggins

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* rename implhook to register

* change default plugins to use register and add machanism to load default plugins

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix linting

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

* fix import

* [pre-commit.ci] auto fixes from pre-commit.com hooks

for more information, see https://pre-commit.ci

Co-authored-by: pre-commit-ci[bot] <66853113+pre-commit-ci[bot]@users.noreply.github.com>

Author: fpliger

pyproject.toml

@@ -21,6 +21,7 @@ Jinja2 = "^3.1.2"
 rich = "^12.3.0"
 rich-click = {extras = ["typer"], version = "^1.3.0"}
 typer = "^0.4.1"
+pluggy = "^1.0.0"
 
 [tool.poetry.dev-dependencies]
 coverage = "^6.3.2"

src/pyscript/__init__.py

@@ -5,7 +5,16 @@
 except ImportError:  # pragma: no cover
     import importlib_metadata as metadata  # type: ignore
 
+try:
+    import rich_click.typer as typer
+except ImportError:  # pragma: no cover
+    import typer  # type: ignore
+from rich.console import Console
+
 try:
     __version__ = metadata.version("pyscript-cli")
 except metadata.PackageNotFoundError:  # pragma: no cover
     __version__ = "unknown"
+
+console = Console()
+app = typer.Typer(add_completion=False)

src/pyscript/cli.py

@@ -1,21 +1,17 @@
 """The main CLI entrypoint and commands."""
+import sys
 import time
 import webbrowser
 from pathlib import Path
 from typing import Any, Optional
 
-from pyscript._generator import file_to_html, string_to_html
-
-try:
-    import rich_click.typer as typer
-except ImportError:  # pragma: no cover
-    import typer  # type: ignore
-from rich.console import Console
+from pluggy import PluginManager
 
-from pyscript import __version__
+from pyscript import __version__, app, console, plugins, typer
+from pyscript._generator import file_to_html, string_to_html
+from pyscript.plugins import hookspecs
 
-console = Console()
-app = typer.Typer(add_completion=False)
+DEFAULT_PLUGINS = ["create", "delete"]
 
 
 def _print_version():
@@ -108,3 +104,27 @@ def wrap(
     if remove_output:
         time.sleep(1)
         output.unlink()
+
+
+pm = PluginManager("pyscript-cli")
+
+pm.add_hookspecs(hookspecs)
+
+for modname in DEFAULT_PLUGINS:
+    importspec = f"pyscript.plugins.{modname}"
+
+    try:
+        __import__(importspec)
+    except ImportError as e:
+        raise ImportError(
+            f'Error importing plugin "{modname}": {e.args[0]}'
+        ).with_traceback(e.__traceback__) from e
+
+    else:
+        mod = sys.modules[importspec]
+        pm.register(mod, modname)
+
+    loaded = pm.load_setuptools_entrypoints("pyscript-cli")
+
+for cmd in pm.hook.pyscript_subcommand():
+    plugins._add_cmd(cmd)

src/pyscript/plugins/__init__.py

@@ -0,0 +1,9 @@
+from pluggy import HookimplMarker
+
+from pyscript import app
+
+register = HookimplMarker("pyscript-cli")
+
+
+def _add_cmd(f):
+    app.command()(f)

src/pyscript/plugins/create.py

@@ -0,0 +1,12 @@
+from pyscript import console, plugins
+
+
+def create():
+    """Creates a new PyScript Project from scratch."""
+    console.print("pyscript create cmd not yet available..", style="bold green")
+    return True
+
+
+@plugins.register
+def pyscript_subcommand():
+    return create

src/pyscript/plugins/delete.py

@@ -0,0 +1,12 @@
+from pyscript import console
+from pyscript.plugins import register
+
+
+def delete():
+    console.print("pyscript delete cmd not yet available..", style="bold red")
+    return True
+
+
+@register
+def pyscript_subcommand():
+    return delete

src/pyscript/plugins/hookspecs.py

@@ -0,0 +1,8 @@
+from pluggy import HookspecMarker
+
+hookspec = HookspecMarker("pyscript-cli")
+
+
+@hookspec
+def pyscript_subcommand():
+    """My special little hook that you can customize."""