gh webhook signature unit test (#82)

core/gh_webhook_handling.py

@@ -67,9 +67,13 @@ def handle_issue(payload, action):
     return action
 
 
-def verify_secret(secret, payload, signature_header):
+def generate_signature(secret, payload):
     hash_object = hmac.new(
         secret.encode("utf-8"), msg=payload, digestmod=hashlib.sha256
     )
-    expected_signature = f"sha256={hash_object.hexdigest()}"
+    return f"sha256={hash_object.hexdigest()}"
+
+
+def verify_secret(secret, payload, signature_header):
+    expected_signature = generate_signature(secret, payload)
     return hmac.compare_digest(expected_signature, signature_header)

core/tests.py

@@ -1 +1,26 @@
-# Create your tests here.
+import json
+from django.test import TestCase
+
+from core.gh_webhook_handling import verify_secret, generate_signature
+
+
+class GHWebhookTestCase(TestCase):
+    def setUp(self):
+        self.secret = "UwU"
+        self.payload = {
+            "sender": {"login": "test_user"},
+            "action": "opened",
+            "pull_request": {"merged": False},
+            "issue": {"state_reason": "completed"},
+        }
+        self.payload_bytes = json.dumps(self.payload).encode("utf-8")
+        self.signature = generate_signature(self.secret, self.payload_bytes)
+
+    def test_valid_signature(self):
+        self.assertTrue(verify_secret(self.secret, self.payload_bytes, self.signature))
+
+    def test_invalid_signature(self):
+        wrong_signature = "silly:3"
+        self.assertFalse(
+            verify_secret(self.secret, self.payload_bytes, wrong_signature)
+        )