Rewrite CLI around action runtime

tests/test_cli.py

@@ -4,6 +4,19 @@ import os
 import subprocess
 import sys
 
+from typer.testing import CliRunner
+
+from flow.cli import app
+
+
+runner = CliRunner()
+
+
+def test_typer_runner_version():
+    result = runner.invoke(app, ["--version"])
+    assert result.exit_code == 0
+    assert "flow" in result.stdout
+
 
 def test_version_flag():
     """Test --version flag works."""