Feature/async support

cliar/cliar.py

@@ -1,5 +1,6 @@
 from argparse import ArgumentParser, RawTextHelpFormatter
-from inspect import signature, getmembers, ismethod, isclass
+from asyncio import get_event_loop
+from inspect import signature, getmembers, ismethod, isclass, iscoroutine
 from collections import OrderedDict
 from typing import List, Iterable, Callable, Set, Type, get_type_hints
 
@@ -291,7 +292,12 @@ def parse(self):
         for subcli in self._subclis:
             subcli.global_args = self.global_args
 
-        if command.handler(**handler_args) == NotImplemented:
+        result = command.handler(**handler_args)
+
+        if iscoroutine(result):
+            result = get_event_loop().run_until_complete(result)
+
+        if result == NotImplemented:
             command.handler.__self__._parser.print_help()
 
     def _root(self):

tests/test_async_fns.py

@@ -0,0 +1,17 @@
+from subprocess import run
+
+
+def test_help(capfd, datadir):
+    run(f'python {datadir/"async_fns.py"} wait -h', shell=True)
+
+    output = capfd.readouterr().out
+
+    assert '-s SECONDS-TO-WAIT, --seconds-to-wait SECONDS-TO-WAIT' in output
+
+def test_wait(capfd, datadir):
+    seconds_to_wait = 1.0
+
+    run(f'python {datadir/"async_fns.py"} wait -s "{seconds_to_wait}"',
+        shell=True)
+    seconds_awaited = float(capfd.readouterr().out.strip())
+    assert round(seconds_awaited, 1) == round(seconds_to_wait, 1)

tests/test_async_fns/async_fns.py

@@ -0,0 +1,15 @@
+import asyncio
+from time import perf_counter
+
+from cliar import Cliar
+
+
+class AsyncFunctions(Cliar):
+    async def wait(self, seconds_to_wait: float = 1.0):
+        t1 = perf_counter()
+        await asyncio.sleep(seconds_to_wait)
+        elapsed = perf_counter() - t1
+        print(elapsed)
+
+if __name__ == "__main__":
+    AsyncFunctions().parse()