Merge pull request #166 from asmacdo/test-arg-parse

Add tests for correct handling of args

test/test_arg_parsing.py

@@ -0,0 +1,42 @@
+import subprocess
+import pytest
+
+
+def test_duct_help() -> None:
+    out = subprocess.check_output(["duct", "--help", "ps"])
+    assert "usage: duct [-h]" in str(out)
+
+
+def test_cmd_help() -> None:
+    out = subprocess.check_output(["duct", "ps", "--help"])
+    assert "ps [options]" in str(out)
+    assert "usage: duct [-h]" not in str(out)
+
+
+@pytest.mark.parametrize(
+    "args",
+    [
+        ["duct", "--unknown", "ps"],
+        ["duct", "--unknown", "ps", "--shouldhavenoeffect"],
+    ],
+)
+def test_duct_unrecognized_arg(args: list) -> None:
+    try:
+        subprocess.check_output(args, stderr=subprocess.STDOUT)
+        pytest.fail("Command should have failed with a non-zero exit code")
+    except subprocess.CalledProcessError as e:
+        assert e.returncode == 2
+        assert "duct: error: unrecognized arguments: --unknown" in str(e.stdout)
+
+
+def test_duct_missing_cmd() -> None:
+    try:
+        subprocess.check_output(
+            ["duct", "--sample-interval", "1"], stderr=subprocess.STDOUT
+        )
+        pytest.fail("Command should have failed with a non-zero exit code")
+    except subprocess.CalledProcessError as e:
+        assert e.returncode == 2
+        assert "duct: error: the following arguments are required: command" in str(
+            e.stdout
+        )