gh-131178: Add tests for site command-line interface

Lib/test/test_site.py

@@ -25,6 +25,7 @@
 import sys
 import sysconfig
 import tempfile
+from textwrap import dedent
 import urllib.error
 import urllib.request
 from unittest import mock
@@ -805,5 +806,112 @@ def test_underpth_dll_file(self):
         self.assertTrue(rc, "sys.path is incorrect")
 
 
+class CommandLineTests(unittest.TestCase):
+    def exists(self, path):
+            if path is not None and os.path.isdir(path):
+                return "exists"
+            else:
+                return "doesn't exist"
+
+    def get_excepted_output(self, *args):
+        if len(args) == 0:
+            user_base = site.getuserbase()
+            user_site = site.getusersitepackages()
+            output = "sys.path = [\n"
+            for dir in sys.path:
+                output += "    %r,\n" % (dir,)
+            output += "]\n"
+            output += f"USER_BASE: {user_base!r} ({self.exists(user_base)})\n"
+            output += f"USER_SITE: {user_site!r} ({self.exists(user_site)})\n"
+            output += f"ENABLE_USER_SITE: {site.ENABLE_USER_SITE!r}\n"
+            return 0, dedent(output).strip()
+
+        buffer = []
+        if '--user-base' in args:
+            buffer.append(site.getuserbase())
+        if '--user-site' in args:
+            buffer.append(site.getusersitepackages())
+
+        if buffer:
+            return_code = 3
+            if site.ENABLE_USER_SITE:
+                return_code = 0
+            elif site.ENABLE_USER_SITE is False:
+                return_code = 1
+            elif site.ENABLE_USER_SITE is None:
+                return_code = 2
+            output = os.pathsep.join(buffer)
+            return return_code, os.path.normpath(dedent(output).strip())
+        else:
+            return 10, None
+
+    def invoke_command_line(self, *args):
+        args = [sys.executable, "-m", "site", *args]
+        env = os.environ.copy()
+        env["PYTHONUTF8"] = "1"
+        env["PYTHONIOENCODING"] = "utf-8"
+
+        proc = subprocess.Popen(args,
+                                stdout=subprocess.PIPE,
+                                stderr=subprocess.STDOUT,
+                                text=True,
+                                env=env,
+                                encoding='utf-8',
+                                errors='replace')
+        proc.wait()
+        output = proc.stdout.read()
+        return_code = proc.returncode
+        proc.stdout.close()
+        return return_code, os.path.normpath(dedent(output).strip())
+
+    @unittest.skipIf(sys.platform == 'wasi', "Popen not supported on WASI")
+    def test_no_args(self):
+        return_code, output = self.invoke_command_line()
+        excepted_return_code, _ = self.get_excepted_output()
+        self.assertEqual(return_code, excepted_return_code)
+        lines = output.splitlines()
+        self.assertEqual(lines[0], "sys.path = [")
+        self.assertEqual(lines[-4], "]")
+        excepted_base = f"USER_BASE: '{site.getuserbase()}'" +\
+            f" ({self.exists(site.getuserbase())})"
+        self.assertEqual(lines[-3], excepted_base)
+        excepted_site = f"USER_SITE: '{site.getusersitepackages()}'" +\
+            f" ({self.exists(site.getusersitepackages())})"
+        self.assertEqual(lines[-2], excepted_site)
+        self.assertEqual(lines[-1], f"ENABLE_USER_SITE: {site.ENABLE_USER_SITE}")
+
+    @unittest.skipIf(sys.platform == 'wasi', "Popen not supported on WASI")
+    def test_unknown_args(self):
+        return_code, output = self.invoke_command_line("--unknown-arg")
+        excepted_return_code, _ = self.get_excepted_output("--unknown-arg")
+        self.assertEqual(return_code, excepted_return_code)
+        self.assertIn('[--user-base] [--user-site]', output)
+
+    @unittest.skipIf(sys.platform == 'wasi', "Popen not supported on WASI")
+    def test_base_arg(self):
+        return_code, output = self.invoke_command_line("--user-base")
+        excepted = self.get_excepted_output("--user-base")
+        excepted_return_code, excepted_output = excepted
+        self.assertEqual(return_code, excepted_return_code)
+        self.assertEqual(output, excepted_output)
+
+    @unittest.skipIf(sys.platform == 'wasi', "Popen not supported on WASI")
+    def test_site_arg(self):
+        return_code, output = self.invoke_command_line("--user-site")
+        excepted = self.get_excepted_output("--user-site")
+        excepted_return_code, excepted_output = excepted
+        self.assertEqual(return_code, excepted_return_code)
+        self.assertEqual(output, excepted_output)
+
+    @unittest.skipIf(sys.platform == 'wasi', "Popen not supported on WASI")
+    def test_both_args(self):
+        return_code, output = self.invoke_command_line("--user-base",
+                                                       "--user-site")
+        excepted = self.get_excepted_output("--user-base", "--user-site")
+        excepted_return_code, excepted_output = excepted
+        self.assertEqual(return_code, excepted_return_code)
+        self.assertEqual(output, excepted_output)
+
+
 if __name__ == "__main__":
     unittest.main()