Files
parsedmarc/tests/test_s3.py
T
Sean Whalen b7b8383fa4 Expand honest test coverage from 59% to 83%; fix two latent bugs (#775)
* Expand honest test coverage from 59% to 83%; fix two latent bugs

271 new tests across the output modules, ES/OS clients, CLI config
parsing, and the top-level parsing surface. Coverage measured against
shipped code only (see [tool.coverage.run] source = ["parsedmarc"]
omit = ["*/parsedmarc/resources/maps/*.py"] in pyproject.toml).

Per-module results:

  s3.py             38% → 100%   (also fixes SMTP-TLS-to-S3 bug below)
  gelf.py           40% → 100%
  syslog.py         46% → 100%
  kafkaclient.py    34% → 100%
  splunk.py         24% → 100%
  loganalytics.py   56% → 100%
  webhook.py        78% → 100%   (also removes redundant try/except)
  elastic.py        36% →  99%
  opensearch.py     40% →  99%
  cli.py            52% →  69%
  __init__.py       74% →  76%   (also fixes append_json bug below)
  utils.py          84% (unchanged in this PR)
  TOTAL             59% →  83%

The remaining 17% is honest. The biggest unreached blocks are
_main() in cli.py and the watch-mode mailbox iteration in __init__.py,
both of which would require either standing up live subsystems (real
Elasticsearch, real IMAP) or mocking deep enough that the test would
verify the mock rather than the code. The PR-A AGENTS.md guidance —
"if 90% requires faking it, ship 85% honestly" — applies here.

Bugs fixed while writing tests:

1. parsedmarc/s3.py — SMTP-TLS-to-S3 was completely broken.
   save_report_to_s3 unconditionally read report["report_metadata"]
   when building S3 object metadata, but RFC 8460 §4.3 SMTP TLS
   reports are flat (no report_metadata sub-object). The CLI's
   surrounding try/except silently swallowed the KeyError, so every
   SMTP-TLS report quietly failed to upload. Also fixes a related
   issue: parse_smtp_tls_report_json stores begin_date as the raw
   ISO-8601 string from the report (per the SMTPTLSReport TypedDict
   and RFC 8460 §4.3), but the S3 code path assumed a datetime
   with .year / .month / .day attributes. Both fixed; the broken
   metadata-extraction branch now uses the flat-report fields, and
   the date branch normalizes via human_timestamp_to_datetime.

2. parsedmarc/__init__.py — append_json corrupted JSON output files
   on the second write. The original implementation opened files in
   "a+" mode, then seek()ed backwards to overwrite the trailing "]"
   with ",\n" before appending more elements. Python's docs are
   explicit (https://docs.python.org/3/library/functions.html#open):
   on POSIX, writes in "a"/"a+" mode always go to EOF regardless of
   seek() position. The result was that the second call produced
   [...]\n],\n[...] -style corrupted output instead of a single
   merged array. Replaced with a read-merge-write pattern: load the
   existing array (if any), append the new elements, rewrite the
   whole file. The CSV cousin append_csv was not affected — it
   doesn't seek backwards.

3. parsedmarc/webhook.py — removed redundant try/except blocks in
   save_aggregate_report_to_webhook / save_failure_report_to_webhook
   / save_smtp_tls_report_to_webhook. _send_to_webhook already
   catches every Exception itself, so the outer except blocks were
   unreachable dead code (covered nothing, defended against nothing,
   and inflated the source-line count without testing value).

Testing approach: mocks at SDK boundaries (boto3 resource, kafka
producer, requests session, opensearch/elasticsearch Document/Search,
azure LogsIngestionClient). Tests verify the parsedmarc-side
transformation logic — document/event construction, index/topic
naming, dedup queries, error wrapping — rather than asserting on
mock invocations as a proxy for behaviour. Where a branch is
defensive against a caller that doesn't exist in the codebase, the
test is omitted (commented in code rather than hidden behind a
pragma).

547 tests total (was 276), all passing. ruff check + format clean.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Document the two bug fixes from this PR in the 10.0.0 changelog

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Document testing standards in AGENTS.md

Adds a "Testing standards" section covering the principles applied in
PR-A (split) and PR-B (coverage expansion):

- Coverage measures shipped code only — don't reintroduce tests/* to
  the scope, don't expand omit, don't use # pragma: no cover.
- Honest tests assert on observable behaviour, not "the mock was called".
  Mock at SDK boundaries; parse the payload that gets sent.
- "If 90% requires faking it, ship 85% honestly" — coverage is a tool,
  not a goal. PR-B's deliberate stops at cli.py 69% and __init__.py 76%
  are the documented precedent for when to halt.
- Verify bug claims against the relevant RFC, internal types, installed
  SDK source, or upstream docs before changing code. Cite the source in
  the commit message and test docstring (RFC 8460 §4.3 and the Python
  open() docs for #775's two bug fixes are the pattern to follow).
- Bugs found while writing tests are fixed in the same PR; the test
  doubles as the regression guard.
- File layout (tests/test_<module>.py) is non-negotiable; module-level
  test loggers need fresh-handler setup so test ordering doesn't break
  assertLogs.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

* Cover the corrupt-file fallback in append_json

Codecov flagged 2 missing patch-coverage lines on PR #775: the
except (json.JSONDecodeError, OSError) branch in append_json, which
falls back to overwriting when the existing file isn't a parseable
JSON array. Two new tests in tests/test_init.py:TestAppendJson
exercise both paths:

- test_corrupt_existing_file_is_overwritten_cleanly: existing file
  contains invalid JSON; append_json overwrites with the new array.
- test_existing_file_with_non_list_root_is_overwritten: existing
  file parses as {"foo": ...} (dict, not list); the isinstance guard
  rejects it and we overwrite cleanly.

Patch coverage now 100% on the bug fix.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

---------

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
2026-05-20 20:35:22 -04:00

221 lines
9.0 KiB
Python

"""Tests for parsedmarc.s3"""
import json
import unittest
from unittest.mock import MagicMock, patch
from parsedmarc.s3 import S3Client
def _sample_aggregate_report():
"""Minimal aggregate report shape used by S3Client.save_*_to_s3."""
return {
"report_metadata": {
"org_name": "example.com",
"org_email": "dmarc@example.com",
"report_id": "agg-123",
"begin_date": "2024-01-15 00:00:00",
"end_date": "2024-01-16 00:00:00",
# not in S3Client.metadata_keys; should NOT appear on the S3 object
"errors": [],
},
"policy_published": {"domain": "example.com", "p": "none"},
"records": [],
}
def _sample_smtp_tls_report():
"""Minimal SMTP TLS report shape as parse_smtp_tls_report_json
produces it — flat, with ISO-string begin_date / end_date pulled
directly from the report JSON."""
return {
"organization_name": "example.com",
"begin_date": "2024-02-03T00:00:00Z",
"end_date": "2024-02-04T00:00:00Z",
"report_id": "tls-456",
"contact_info": "tls-admin@example.com",
"policies": [],
}
class TestS3ClientInit(unittest.TestCase):
"""S3Client.__init__ delegates to boto3.resource() with the supplied
credentials and endpoint. A regression in argument names or order
would silently send reports to the wrong bucket or auth as the wrong
principal."""
def test_init_forwards_credentials_to_boto3(self):
with patch("parsedmarc.s3.boto3.resource") as mock_resource:
S3Client(
bucket_name="my-bucket",
bucket_path="dmarc",
region_name="us-east-1",
endpoint_url="https://s3.example.com",
access_key_id="AKIA-test",
secret_access_key="secret-test",
)
mock_resource.assert_called_once_with(
"s3",
region_name="us-east-1",
endpoint_url="https://s3.example.com",
aws_access_key_id="AKIA-test",
aws_secret_access_key="secret-test",
)
def test_init_caches_bucket_handle(self):
"""self.bucket is the Bucket(bucket_name) on the boto3 resource,
so subsequent save_* calls go to the right bucket."""
with patch("parsedmarc.s3.boto3.resource") as mock_resource:
mock_resource.return_value.Bucket.return_value = "bucket-handle"
client = S3Client(
bucket_name="my-bucket",
bucket_path="dmarc",
region_name="us-east-1",
endpoint_url="https://s3.example.com",
access_key_id="k",
secret_access_key="s",
)
mock_resource.return_value.Bucket.assert_called_once_with("my-bucket")
self.assertEqual(client.bucket, "bucket-handle")
class TestS3ClientSavePathsAndMetadata(unittest.TestCase):
"""The S3 key is built from the report's begin_date and report_id.
Wrong format = unfindable reports; wrong metadata filtering = secret
leakage onto the S3 object."""
def _client_with_mock_bucket(self):
with patch("parsedmarc.s3.boto3.resource"):
client = S3Client(
bucket_name="b",
bucket_path="dmarc",
region_name="us-east-1",
endpoint_url="https://s3.example.com",
access_key_id="k",
secret_access_key="s",
)
client.bucket = MagicMock()
return client
def test_aggregate_dispatches_with_aggregate_in_key_path(self):
"""save_aggregate_report_to_s3 puts the object under
<bucket_path>/aggregate/year=YYYY/month=MM/day=DD/<report_id>.json."""
client = self._client_with_mock_bucket()
client.save_aggregate_report_to_s3(_sample_aggregate_report())
client.bucket.put_object.assert_called_once()
call = client.bucket.put_object.call_args
self.assertEqual(
call.kwargs["Key"],
"dmarc/aggregate/year=2024/month=01/day=15/agg-123.json",
)
def test_failure_dispatches_with_failure_in_key_path(self):
client = self._client_with_mock_bucket()
report = _sample_aggregate_report()
report["report_metadata"]["report_id"] = "fail-789"
client.save_failure_report_to_s3(report)
key = client.bucket.put_object.call_args.kwargs["Key"]
self.assertEqual(key, "dmarc/failure/year=2024/month=01/day=15/fail-789.json")
def test_smtp_tls_uses_report_begin_date(self):
"""SMTP TLS reports are flat — no report_metadata — and
begin_date is the ISO string produced by parse_smtp_tls_report_json.
The S3 path-builder parses that string into a datetime for the
year=/month=/day= key segments.
Regression: an earlier version assumed ALL reports carried a
report_metadata sub-object, which crashed with KeyError on every
SMTP TLS save. The CLI swallowed the error and only logged it,
so the bug was invisible in production."""
client = self._client_with_mock_bucket()
client.save_smtp_tls_report_to_s3(_sample_smtp_tls_report())
key = client.bucket.put_object.call_args.kwargs["Key"]
self.assertEqual(key, "dmarc/smtp_tls/year=2024/month=02/day=03/tls-456.json")
def test_smtp_tls_metadata_comes_from_flat_report_fields(self):
"""SMTP TLS object metadata is built from the flat report
instead of report_metadata. organization_name is renamed to
org_name (the S3 metadata key) for consistency with DMARC."""
client = self._client_with_mock_bucket()
client.save_smtp_tls_report_to_s3(_sample_smtp_tls_report())
meta = client.bucket.put_object.call_args.kwargs["Metadata"]
self.assertEqual(meta["org_name"], "example.com")
self.assertEqual(meta["report_id"], "tls-456")
self.assertEqual(meta["begin_date"], "2024-02-03T00:00:00Z")
self.assertEqual(meta["end_date"], "2024-02-04T00:00:00Z")
def test_object_body_is_json_serialized_report(self):
client = self._client_with_mock_bucket()
report = _sample_aggregate_report()
client.save_aggregate_report_to_s3(report)
body = client.bucket.put_object.call_args.kwargs["Body"]
# Round-trip the JSON to make sure it actually deserializes and
# carries every top-level key the source report had.
self.assertEqual(json.loads(body), report)
def test_metadata_filtered_to_documented_keys_only(self):
"""report_metadata fields outside `metadata_keys` must not be
attached to the S3 object — they could leak large or sensitive
payloads (errors lists, internal IDs) into object metadata."""
client = self._client_with_mock_bucket()
report = _sample_aggregate_report()
report["report_metadata"]["errors"] = ["a", "b"]
report["report_metadata"]["internal_diag"] = "secret"
client.save_aggregate_report_to_s3(report)
meta = client.bucket.put_object.call_args.kwargs["Metadata"]
self.assertEqual(
set(meta.keys()),
{"org_name", "org_email", "report_id", "begin_date", "end_date"},
)
self.assertNotIn("errors", meta)
self.assertNotIn("internal_diag", meta)
class TestS3ClientClose(unittest.TestCase):
"""close() must release the underlying boto3 client; a slow leak
here matters for long-running watch-mode processes."""
def test_close_calls_underlying_client_close(self):
with patch("parsedmarc.s3.boto3.resource") as mock_resource:
client = S3Client(
bucket_name="b",
bucket_path="p",
region_name="r",
endpoint_url="https://s3.example.com",
access_key_id="k",
secret_access_key="s",
)
client.close()
mock_resource.return_value.meta.client.close.assert_called_once()
def test_close_swallows_exceptions_from_underlying_client(self):
"""close() is called during shutdown/reload; if boto3 raises
from the close path, we don't want it to propagate and prevent
clean exit. The except is defensive but deliberate."""
with patch("parsedmarc.s3.boto3.resource") as mock_resource:
mock_resource.return_value.meta.client.close.side_effect = RuntimeError(
"boom"
)
client = S3Client(
bucket_name="b",
bucket_path="p",
region_name="r",
endpoint_url="https://s3.example.com",
access_key_id="k",
secret_access_key="s",
)
# Should not raise.
client.close()
class TestS3ClientBackwardCompatAlias(unittest.TestCase):
def test_forensic_alias_points_to_failure_method(self):
self.assertIs(
S3Client.save_forensic_report_to_s3, # type: ignore[attr-defined]
S3Client.save_failure_report_to_s3,
)
if __name__ == "__main__":
unittest.main(verbosity=2)