feat: Support async default ValueFrom functions.

examples/defer_import_slow_startup/defer_import/main.py

@@ -17,4 +17,4 @@ class MeanCommand:
 
 
 def main():
-    return cappa.invoke(DeferImport)
+    cappa.invoke(DeferImport)

examples/defer_import_slow_startup/pyproject.toml

@@ -2,18 +2,19 @@
 name = "defer-import"
 version = "0.0.1"
 dependencies = [
-    "pandas >= 2.2.3",
+    "pandas",
     "cappa",
 ]
+requires-python = ">=3.8,<4"
 
 [project.scripts]
 defer-import = "defer_import.main:main"
 
 [tool.uv.sources]
 cappa = {path = "../.."}
 
-[tool.uv]
-dev-dependencies = [
+[dependency-groups]
+dev = [
     "mypy >= 1.0.0",
     "pyright >= 1.1.398",
     "basedpyright >= 1.29.1",

meow.py

@@ -0,0 +1,34 @@
+import asyncio
+from dataclasses import dataclass
+from typing import Annotated, TypeVar
+
+from rich.prompt import IntPrompt
+
+import cappa
+from cappa import ValueFrom
+
+T = TypeVar("T")
+
+
+async def test() -> list[int]:
+    return [1]
+
+
+async def gen() -> int:
+    ids = await test()
+    business = IntPrompt.ask("choices a business", choices=[str(_id) for _id in ids])
+    return business
+
+
+@dataclass
+class Test:
+    business: Annotated[
+        int,
+        cappa.Arg(default=ValueFrom(gen), help="Business ID"),
+    ]
+
+    async def __call__(self):
+        print(self.business)
+
+
+asyncio.run(cappa.invoke_async(Test))

src/cappa/__init__.py

@@ -1,10 +1,10 @@
-from cappa.base import collect, command, invoke, invoke_async, parse
+from cappa.base import collect, command, invoke, invoke_async, parse, parse_async
 from cappa.command import Command
 from cappa.completion.types import Completion
 from cappa.default import Confirm, Default, Env, Prompt, ValueFrom
 from cappa.file_io import FileMode
 from cappa.help import HelpFormattable, HelpFormatter
-from cappa.invoke import Dep, Self
+from cappa.invoke.types import Dep, Self
 from cappa.output import Exit, HelpExit, Output
 from cappa.parse import default_parse, unpack_arguments
 from cappa.state import State
@@ -52,5 +52,6 @@
     "invoke",
     "invoke_async",
     "parse",
+    "parse_async",
     "unpack_arguments",
 ]

src/cappa/argparse.py

@@ -7,7 +7,7 @@
 from cappa.arg import Arg, ArgAction, Group
 from cappa.command import Command, Subcommand
 from cappa.help import ArgGroup
-from cappa.invoke import fulfill_deps
+from cappa.invoke.base import fulfill_deps
 from cappa.output import Exit, HelpExit, Output
 from cappa.parser import RawOption, Value
 from cappa.typing import assert_type