Add completions, Add suggestions list to Argument

tests/test_parsers/test_completions.py

@@ -0,0 +1,18 @@
+import pytest
+
+from falyx.parser.command_argument_parser import CommandArgumentParser
+
+
+@pytest.mark.asyncio
+@pytest.mark.parametrize(
+    "input_tokens, expected",
+    [
+        ([""], ["--help", "--tag", "-h"]),
+        (["--ta"], ["--tag"]),
+        (["--tag"], ["analytics", "build"]),
+    ],
+)
+async def test_suggest_next(input_tokens, expected):
+    parser = CommandArgumentParser(...)
+    parser.add_argument("--tag", choices=["analytics", "build"])
+    assert sorted(parser.suggest_next(input_tokens)) == sorted(expected)