From 154328e7273481f62d5ce877a5c310b72dca9ebb Mon Sep 17 00:00:00 2001
From: tangyuan0821 <tangyuan0821@email.cn>
Date: Tue, 23 Jun 2026 16:30:34 +0800
Subject: [PATCH 1/2] gh-131178: Add tests for pydoc command-line interface

---
 Lib/pydoc.py                      |  1 +
 Lib/test/test_pydoc/test_pydoc.py | 61 +++++++++++++++++++++++++++++++
 2 files changed, 62 insertions(+)

diff --git a/Lib/pydoc.py b/Lib/pydoc.py
index fe42592530c2cfd..a0626cb8bb9d338 100644
--- a/Lib/pydoc.py
+++ b/Lib/pydoc.py
@@ -2850,6 +2850,7 @@ class BadUsage(Exception): pass
     directory.  If <name> contains a '{sep}', it is treated as a filename; if
     it names a directory, documentation is written for all the contents.
 """.format(cmd=cmd, sep=os.sep))
+        sys.exit(1)
 
 if __name__ == '__main__':
     cli()
diff --git a/Lib/test/test_pydoc/test_pydoc.py b/Lib/test/test_pydoc/test_pydoc.py
index 5543c664528e6c8..687c460033b9915 100644
--- a/Lib/test/test_pydoc/test_pydoc.py
+++ b/Lib/test/test_pydoc/test_pydoc.py
@@ -2462,6 +2462,67 @@ def __version__(self):
             self.assertEqual(len(w), 1)
 
 
+@support.force_not_colorized_test_class
+class TestPydocCLI(unittest.TestCase):
+    """Tests for the pydoc command-line interface."""
+
+    def test_show_doc(self):
+        rc, out, err = assert_python_ok('-m', 'pydoc', 'os')
+        self.assertEqual(rc, 0)
+        self.assertIn(b'os', out)
+        self.assertEqual(err, b'')
+
+    def test_show_doc_builtin(self):
+        rc, out, err = assert_python_ok('-m', 'pydoc', 'list')
+        self.assertEqual(rc, 0)
+        self.assertIn(b'list', out)
+        self.assertEqual(err, b'')
+
+    def test_show_doc_keyword(self):
+        rc, out, err = assert_python_ok('-m', 'pydoc', 'for')
+        self.assertEqual(rc, 0)
+        self.assertIn(b'for', out)
+        self.assertEqual(err, b'')
+
+    def test_keyword_search(self):
+        rc, out, err = assert_python_ok('-m', 'pydoc', '-k', 'thread')
+        self.assertEqual(rc, 0)
+        # Either matching modules are listed or no documentation is found.
+        self.assertTrue(
+            b'thread' in out.lower() or
+            b'no Python documentation found' in out,
+            out
+        )
+        self.assertEqual(err, b'')
+
+    def test_write_html(self):
+        with os_helper.temp_dir() as tmpdir:
+            rc, out, err = assert_python_ok('-m', 'pydoc', '-w', 'os',
+                                            __cwd=tmpdir)
+            self.assertEqual(rc, 0)
+            self.assertIn(b'wrote os.html', out.lower())
+            self.assertEqual(err, b'')
+            self.assertTrue(os.path.exists(os.path.join(tmpdir, 'os.html')))
+
+    def test_nonexistent_module(self):
+        rc, out, err = assert_python_failure('-m', 'pydoc', 'nonexistent_module')
+        self.assertEqual(rc, 1)
+        self.assertIn(b'nonexistent_module', out)
+        self.assertEqual(err, b'')
+
+    def test_no_args(self):
+        rc, out, err = assert_python_failure('-m', 'pydoc')
+        self.assertEqual(rc, 1)
+        self.assertIn(b'pydoc - the Python documentation tool', out)
+        self.assertEqual(err, b'')
+
+    def test_invalid_flag(self):
+        rc, out, err = assert_python_failure('-m', 'pydoc', '--xyz')
+        self.assertEqual(rc, 1)
+        self.assertIn(b'pydoc - the Python documentation tool', out)
+        self.assertEqual(err, b'')
+
+
 def setUpModule():
     thread_info = threading_helper.threading_setup()
     unittest.addModuleCleanup(threading_helper.threading_cleanup, *thread_info)

From d5a415361bd016c37816cd6cf389e3d09ff31cac Mon Sep 17 00:00:00 2001
From: tangyuan0821 <tangyuan0821@email.cn>
Date: Tue, 23 Jun 2026 16:36:11 +0800
Subject: [PATCH 2/2] gh-131178: Add news entries for pydoc CLI tests

---
 .../next/Library/2026-06-23-16-34-09.gh-issue-131178.XyZaBc.rst  | 1 +
 .../next/Tests/2026-06-23-16-34-08.gh-issue-131178.LmNpQr.rst    | 1 +
 2 files changed, 2 insertions(+)
 create mode 100644 Misc/NEWS.d/next/Library/2026-06-23-16-34-09.gh-issue-131178.XyZaBc.rst
 create mode 100644 Misc/NEWS.d/next/Tests/2026-06-23-16-34-08.gh-issue-131178.LmNpQr.rst

diff --git a/Misc/NEWS.d/next/Library/2026-06-23-16-34-09.gh-issue-131178.XyZaBc.rst b/Misc/NEWS.d/next/Library/2026-06-23-16-34-09.gh-issue-131178.XyZaBc.rst
new file mode 100644
index 000000000000000..8560098689c20f2
--- /dev/null
+++ b/Misc/NEWS.d/next/Library/2026-06-23-16-34-09.gh-issue-131178.XyZaBc.rst
@@ -0,0 +1 @@
+Make :mod:`pydoc` exit with code 1 when invoked with no arguments or an invalid option.
diff --git a/Misc/NEWS.d/next/Tests/2026-06-23-16-34-08.gh-issue-131178.LmNpQr.rst b/Misc/NEWS.d/next/Tests/2026-06-23-16-34-08.gh-issue-131178.LmNpQr.rst
new file mode 100644
index 000000000000000..919c7481612c0ea
--- /dev/null
+++ b/Misc/NEWS.d/next/Tests/2026-06-23-16-34-08.gh-issue-131178.LmNpQr.rst
@@ -0,0 +1 @@
+Add CLI tests for :mod:`pydoc`.