fix: migrate pact Verifier to pact-python 3.x API

pact-python 3.x (released after the 1.x series) ships a new Rust FFI-based
verifier that breaks backward compatibility with the old Ruby-based verifier.

The constructor and verification call both changed:

Old API (pact-python 1.x):
    verifier = Verifier(provider='lms', provider_base_url=url)
    output, _ = verifier.verify_pacts(pact_file, headers=[...], provider_states_setup_url=...)
    assert output == 0

New API (pact-python 3.x):
    Verifier(name='lms')
        .add_transport(url=url)
        .add_source(pact_file)
        .add_custom_header('Pact-Authentication', 'Allow')
        .state_handler(provider_states_setup_url, body=True)
        .verify()

Key differences:
- `provider` → `name`, `provider_base_url` → `.add_transport(url=...)`
- `verify_pacts()` is gone; replaced by fluent `.add_source()` + `.verify()`
- Headers are set individually via `.add_custom_header(name, value)` rather
  than as a list of `Key: Value` strings
- `provider_states_setup_url` becomes `.state_handler(url, body=True)`;
  `body=True` is required for URL-based handlers and matches what the
  provider state views already expect (they read from request.body)
- `verify()` raises RuntimeError on failure instead of returning a non-zero
  exit code, so the `assert output == 0` is no longer needed
- The verifier is now created fresh inside the test method rather than in
  setUpClass, because `add_source` and `add_custom_header` accumulate state
  on the underlying FFI handle — sharing a verifier across multiple test
  invocations would cause duplicate sources/headers on the second run

Co-Authored-By: Claude Sonnet 4.6 <[email protected]>

Author: feanil

lms/djangoapps/course_api/blocks/tests/pacts/verify_pact.py

@@ -17,24 +17,15 @@
 class ProviderVerificationServer(LiveServerTestCase):
     """ Django Test Live Server for Pact Verification """
 
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-
-        cls.verifier = Verifier(
-            provider='lms',
-            provider_base_url=cls.live_server_url,
-        )
-
-    @classmethod
-    def tearDownClass(cls):
-        super().tearDownClass()
-
     def test_verify_pact(self):
-        output, _ = self.verifier.verify_pacts(
-            os.path.join(PACT_DIR, PACT_FILE),
-            headers=['Pact-Authentication: Allow', ],
-            provider_states_setup_url=f"{self.live_server_url}{reverse('provider-state-view')}",
+        (
+            Verifier(name='lms')
+            .add_transport(url=self.live_server_url)
+            .add_source(os.path.join(PACT_DIR, PACT_FILE))
+            .add_custom_header('Pact-Authentication', 'Allow')
+            .state_handler(
+                f"{self.live_server_url}{reverse('provider-state-view')}",
+                body=True,
+            )
+            .verify()
         )
-
-        assert output == 0

lms/djangoapps/courseware/tests/pacts/verify_pact.py

@@ -17,24 +17,15 @@
 class ProviderVerificationServer(LiveServerTestCase):
     """ Django Test Live Server for Pact Verification """
 
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-
-        cls.verifier = Verifier(
-            provider='lms',
-            provider_base_url=cls.live_server_url,
-        )
-
-    @classmethod
-    def tearDownClass(cls):
-        super().tearDownClass()
-
     def test_verify_pact(self):
-        output, _ = self.verifier.verify_pacts(
-            os.path.join(PACT_DIR, PACT_FILE),
-            headers=['Pact-Authentication: Allow', ],
-            provider_states_setup_url=f"{self.live_server_url}{reverse('courseware_xblock_handler_provider_state')}",
+        (
+            Verifier(name='lms')
+            .add_transport(url=self.live_server_url)
+            .add_source(os.path.join(PACT_DIR, PACT_FILE))
+            .add_custom_header('Pact-Authentication', 'Allow')
+            .state_handler(
+                f"{self.live_server_url}{reverse('courseware_xblock_handler_provider_state')}",
+                body=True,
+            )
+            .verify()
         )
-
-        assert output == 0

openedx/core/djangoapps/courseware_api/tests/pacts/verify_pact.py

@@ -20,27 +20,16 @@
 class ProviderVerificationServer(LiveServerTestCase):
     """ Live Server for Pact Verification"""
 
-    @classmethod
-    def setUpClass(cls):
-        super().setUpClass()
-
-        cls.PACT_URL = cls.live_server_url
-
-        cls.verifier = Verifier(
-            provider='lms',
-            provider_base_url=cls.PACT_URL,
-        )
-
-    @classmethod
-    def tearDownClass(cls):
-        super().tearDownClass()
-
     @override_waffle_flag(DISCOUNT_APPLICABILITY_FLAG, active=True)
     def test_verify_pact(self):
-        output, _ = self.verifier.verify_pacts(
-            os.path.join(PACT_DIR, PACT_FILE),
-            headers=['Pact-Authentication: Allow', ],
-            provider_states_setup_url=f"{self.PACT_URL}{reverse('courseware_api:provider-state-view')}",
+        (
+            Verifier(name='lms')
+            .add_transport(url=self.live_server_url)
+            .add_source(os.path.join(PACT_DIR, PACT_FILE))
+            .add_custom_header('Pact-Authentication', 'Allow')
+            .state_handler(
+                f"{self.live_server_url}{reverse('courseware_api:provider-state-view')}",
+                body=True,
+            )
+            .verify()
         )
-
-        assert output == 0