Add some tests for header validation

See #179

ingest/tests.py

@@ -32,7 +32,8 @@ from bsmain.management.commands.send_json import Command as SendJsonCommand
 from .views import BaseIngestAPIView
 from .parsers import readuntil, NewlineFinder, ParseError, LengthFinder, StreamingEnvelopeParser
 from .event_counter import check_for_thresholds
-from .header_validators import validate_envelope_headers
+from .header_validators import (
+    validate_envelope_headers, validate_item_headers, filter_valid_item_headers, filter_valid_envelope_headers)
 
 from bugsink.exceptions import ViolatedExpectation
 
@@ -918,3 +919,56 @@ class HeaderValidationTest(RegularTestCase):
 
         with self.assertRaises(ParseError):
             validate_envelope_headers({"sent_at": "2025-07-31T23:05:37.0926+12:00"})
+
+    def test_dsn(self):
+        validate_envelope_headers({"dsn": "https://public@example.com/1"})
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"dsn": "not-a-dsn"})
+
+    def test_sdk(self):
+        validate_envelope_headers({"sdk": {}})
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"sdk": "1.0"})
+
+    def test_event_id(self):
+        valid32 = "a" * 32
+        valid36 = "123e4567-e89b-12d3-a456-426614174000"
+        validate_envelope_headers({"event_id": valid32})
+        validate_envelope_headers({"event_id": valid36})
+
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"event_id": "xyz"})
+
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"event_id": "g" * 32})
+
+    def test_filter_valid_envelope_headers(self):
+        headers = {
+            "dsn": "bad",
+            "sent_at": "2025-08-02T00:00:00Z",
+            "sdk": "bad",
+            "event_id": "deadbeefdeadbeefdeadbeefdeadbeef"
+        }
+
+        self.assertEqual(filter_valid_envelope_headers(headers), {
+            "sent_at": "2025-08-02T00:00:00Z",
+            "event_id": "deadbeefdeadbeefdeadbeefdeadbeef",
+        })
+
+    def test_validate_item_headers_non_event_doesnt_raise(self):
+        validate_item_headers({"type": "transaction", "length": -1})
+
+    def test_validate_item_headers(self):
+        validate_item_headers({"type": "event", "length": 0})
+
+        with self.assertRaises(ParseError):
+            validate_item_headers({"type": "event", "length": -1})
+
+    def test_filter_valid_item_headers_non_event(self):
+        header = {"type": "transaction", "length": -1}
+        self.assertIs(filter_valid_item_headers(header), header)
+
+    def test_filter_valid_item_headers_event(self):
+        self.assertEqual(filter_valid_item_headers(
+            {"type": "event", "length": 3, "foo": 1}),
+            {"type": "event", "length": 3})