test(ci): cover assurance gate entry points

tests/unit/test_unittest_gate.py

@@ -3,8 +3,11 @@
 from __future__ import annotations
 
 import unittest
+from contextlib import redirect_stderr
+from io import StringIO
+from unittest.mock import Mock, patch
 
-from scripts.unittest_gate import assurance_errors
+from scripts.unittest_gate import assurance_errors, main
 
 
 class TestAssuranceErrors(unittest.TestCase):
@@ -29,6 +32,60 @@ class TestAssuranceErrors(unittest.TestCase):
         )
         self.assertEqual(["1 test(s) skipped in a no-skip suite"], errors)
 
+    def test_main_accepts_successful_assured_suite(self) -> None:
+        result = Mock(
+            testsRun=22,
+            skipped=[],
+            wasSuccessful=Mock(return_value=True),
+        )
+        runner = Mock()
+        runner.run.return_value = result
+        with patch(
+            "scripts.unittest_gate.unittest.defaultTestLoader.discover",
+            return_value=Mock(),
+        ) as discover, patch(
+            "scripts.unittest_gate.unittest.TextTestRunner",
+            return_value=runner,
+        ) as runner_type:
+            self.assertEqual(
+                0,
+                main([
+                    "-s", "tests/integration",
+                    "-t", ".",
+                    "-p", "test_*.py",
+                    "--minimum-executed", "22",
+                    "--fail-on-skip",
+                    "-v",
+                ]),
+            )
+        discover.assert_called_once_with(
+            "tests/integration", pattern="test_*.py", top_level_dir="."
+        )
+        runner_type.assert_called_once_with(verbosity=2)
+
+    def test_main_rejects_unsuccessful_underfilled_suite(self) -> None:
+        result = Mock(
+            testsRun=1,
+            skipped=[(Mock(), "not available")],
+            wasSuccessful=Mock(return_value=False),
+        )
+        runner = Mock()
+        runner.run.return_value = result
+        error = StringIO()
+        with patch(
+            "scripts.unittest_gate.unittest.defaultTestLoader.discover",
+            return_value=Mock(),
+        ), patch(
+            "scripts.unittest_gate.unittest.TextTestRunner",
+            return_value=runner,
+        ), redirect_stderr(error):
+            self.assertEqual(
+                1,
+                main(["--minimum-executed", "2", "--fail-on-skip"]),
+            )
+        self.assertIn("below required minimum", error.getvalue())
+        self.assertIn("skipped in a no-skip suite", error.getvalue())
+
 
 if __name__ == "__main__":
     unittest.main()