Add command-line option sanity check tests

tests/cli_test.py

@@ -0,0 +1,96 @@
+"""Sanity checks for command-line options."""
+import re
+from subprocess import PIPE
+from subprocess import Popen
+
+import pytest
+
+
+@pytest.fixture
+def current_version():
+    return open('VERSION').read().strip()
+
+
+def test_no_arguments_prints_usage(both_debug_modes, both_setsid_modes):
+    proc = Popen(('dumb-init'), stderr=PIPE)
+    _, stderr = proc.communicate()
+    assert proc.returncode != 0
+    assert stderr == (
+        b'Usage: dumb-init [option] program [args]\n'
+        b'Try dumb-init --help for full usage.\n'
+    )
+
+
+@pytest.mark.parametrize('flag', ['-h', '--help'])
+def test_help_message(flag, both_debug_modes, both_setsid_modes, current_version):
+    """dumb-init should say something useful when called with the help flag,
+    and exit zero.
+    """
+    proc = Popen(('dumb-init', flag), stderr=PIPE)
+    _, stderr = proc.communicate()
+    assert proc.returncode == 0
+    assert stderr == (
+        b'dumb-init v' + current_version.encode('ascii') + b'\n'
+        b'Usage: dumb-init [option] command [[arg] ...]\n'
+        b'\n'
+        b'dumb-init is a simple process supervisor that forwards signals to children.\n'
+        b'It is designed to run as PID1 in minimal container environments.\n'
+        b'\n'
+        b'Optional arguments:\n'
+        b'   -c, --single-child   Run in single-child mode.\n'
+        b'                        In this mode, signals are only proxies to the\n'
+        b'                        direct child and not any of its ancestors.\n'
+        b'   -v, --verbose        Print debugging information to stderr.\n'
+        b'   -h, --help           Print this help message and exit.\n'
+        b'   -V, --version        Print the current version and exit.\n'
+        b'\n'
+        b'Full help is available online at https://github.com/Yelp/dumb-init\n'
+    )
+
+
+@pytest.mark.parametrize('flag', ['-V', '--version'])
+def test_version_message(flag, both_debug_modes, both_setsid_modes, current_version):
+    """dumb-init should print its version when asked to."""
+
+    proc = Popen(('dumb-init', flag), stderr=PIPE)
+    _, stderr = proc.communicate()
+    assert proc.returncode == 0
+    assert stderr == b'dumb-init v' + current_version.encode('ascii') + b'\n'
+
+
+@pytest.mark.parametrize('flag', ['-v', '--verbose'])
+def test_verbose(flag):
+    """dumb-init should print debug output when asked to."""
+    proc = Popen(('dumb-init', flag, 'echo', 'oh,', 'hi'), stdout=PIPE, stderr=PIPE)
+    stdout, stderr = proc.communicate()
+    assert proc.returncode == 0
+    assert stdout == b'oh, hi\n'
+    assert re.match(
+        (
+            b'^\[dumb-init\] Child spawned with PID [0-9]+\.\n'
+            b'\[dumb-init\] setsid complete\.\n'
+            b'\[dumb-init\] A child with PID [0-9]+ exited with exit status 0.\n'
+            b'\[dumb-init\] Forwarded signal 15 to children\.\n'
+            b'\[dumb-init\] Child exited with status 0\. Goodbye\.\n$'
+        ),
+        stderr,
+    )
+
+
+@pytest.mark.parametrize('flag1', ['-v', '--verbose'])
+@pytest.mark.parametrize('flag2', ['-c', '--single-child'])
+def test_verbose_and_single_child(flag1, flag2):
+    """dumb-init should print debug output when asked to."""
+    proc = Popen(('dumb-init', flag1, flag2, 'echo', 'oh,', 'hi'), stdout=PIPE, stderr=PIPE)
+    stdout, stderr = proc.communicate()
+    assert proc.returncode == 0
+    assert stdout == b'oh, hi\n'
+    assert re.match(
+        (
+            b'^\[dumb-init\] Child spawned with PID [0-9]+\.\n'
+            b'\[dumb-init\] A child with PID [0-9]+ exited with exit status 0.\n'
+            b'\[dumb-init\] Forwarded signal 15 to children\.\n'
+            b'\[dumb-init\] Child exited with status 0\. Goodbye\.\n$'
+        ),
+        stderr,
+    )

tests/help_message_test.py

@@ -1,39 +0,0 @@
-from subprocess import PIPE
-from subprocess import Popen
-
-import pytest
-
-
-def test_exit_status(both_debug_modes, both_setsid_modes):
-    """dumb-init should say something useful when called with no arguments, and
-    exit nonzero.
-    """
-    proc = Popen(('dumb-init'), stderr=PIPE)
-    _, stderr = proc.communicate()
-    assert proc.returncode != 0
-    assert stderr == (
-        b'Usage: dumb-init [option] program [args]\n'
-        b'Try dumb-init --help for full usage.\n'
-    )
-
-
-@pytest.mark.parametrize('flag', ['-h', '--help'])
-def test_help_message(flag, both_debug_modes, both_setsid_modes):
-    """dumb-init should say something useful when called with the help flag,
-    and exit zero.
-    """
-    proc = Popen(('dumb-init', flag), stderr=PIPE)
-    _, stderr = proc.communicate()
-    assert proc.returncode == 0
-    assert len(stderr) >= 50
-
-
-@pytest.mark.parametrize('flag', ['-V', '--version'])
-def test_version_message(flag, both_debug_modes, both_setsid_modes):
-    """dumb-init should print its version when asked to."""
-    version = open('VERSION', 'rb').read()
-
-    proc = Popen(('dumb-init', flag), stderr=PIPE)
-    _, stderr = proc.communicate()
-    assert proc.returncode == 0
-    assert stderr == b'dumb-init v' + version