From 5fb48e1e90afdff509a83cc900889df5e5031d93 Mon Sep 17 00:00:00 2001
From: Klaas van Schelven <klaas@vanschelven.com>
Date: Fri, 1 Aug 2025 10:01:41 +0200
Subject: [PATCH] sent_at validation: support 00+00

Fix #179
---
 ingest/header_validators.py | 20 +++++++++++++++-----
 ingest/tests.py             | 19 +++++++++++++++++++
 2 files changed, 34 insertions(+), 5 deletions(-)

diff --git a/ingest/header_validators.py b/ingest/header_validators.py
index a8f95b8..7add3ed 100644
--- a/ingest/header_validators.py
+++ b/ingest/header_validators.py
@@ -16,7 +16,7 @@ from .exceptions import ParseError
 # * item headers -> only those that are relevant for "event" items
 
 
-_RFC3339_Z = re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d+)?Z$")
+_RFC3339_Z = re.compile(r"^\d{4}-\d{2}-\d{2}T\d{2}:\d{2}:\d{2}(?:\.\d{1,9})?(Z|\+00:00)$")
 _UUID32 = re.compile(r"^[0-9a-fA-F]{32}$")
 _UUID36 = re.compile(r"^[0-9a-fA-F]{8}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{4}-[0-9a-fA-F]{12}$")
 
@@ -35,12 +35,22 @@ def validate_sdk(v):
 
 def validate_sent_at(v):
     if not isinstance(v, str) or not _RFC3339_Z.match(v):
-        raise ParseError(f'Envelope header "sent_at" must be an RFC3339 UTC timestamp ending in Z: {v}')
+        raise ParseError(f'Envelope header "sent_at" must be an RFC3339 UTC timestamp: {v}')
 
     try:
-        datetime.strptime(v, "%Y-%m-%dT%H:%M:%SZ")
-    except ValueError:
-        datetime.fromisoformat(v.replace("Z", "+00:00"))
+        # Convert Z to +00:00 for isoformat compatibility
+        if v.endswith("Z"):
+            v = v[:-1] + "+00:00"
+
+        # Truncate fractional seconds to 6 digits (Python's datetime.fromisoformat supports up to 6 digits)
+        v = re.sub(
+            r"(\.\d{1,6})\d*(\+00:00)$",  # keep only first 6 digits before +00:00
+            r"\1\2",
+            v
+        )
+        return datetime.fromisoformat(v)
+    except ValueError as e:
+        raise ParseError(f'Envelope header "sent_at" is not a valid RFC3339 timestamp: {e}') from e
 
 
 def validate_event_id(v):
diff --git a/ingest/tests.py b/ingest/tests.py
index eeb3f56..6f66613 100644
--- a/ingest/tests.py
+++ b/ingest/tests.py
@@ -32,6 +32,7 @@ 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 bugsink.exceptions import ViolatedExpectation
 
@@ -899,3 +900,21 @@ class TestParser(RegularTestCase):
             envelope_headers)
 
         # the rest of the test is not repeated here
+
+
+class HeaderValidationTest(RegularTestCase):
+    # incomplete: regression-based-first (we'll add more later)
+
+    def test_sent_at_trailing_zeros(self):
+        # regression test for #179
+        validate_envelope_headers({"sent_at": "2025-07-31T23:05:37.0926585+00:00"})
+        validate_envelope_headers({"sent_at": "2025-07-31T23:05:37.0926585Z"})
+
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"sent_at": "garbage"})
+
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"sent_at": "2025-07-31T23:05:37.0926585032123+00:00"})
+
+        with self.assertRaises(ParseError):
+            validate_envelope_headers({"sent_at": "2025-07-31T23:05:37.0926+12:00"})