The fix here is correct — nice catch tracing this back from the test-engine-client. This shouldn't hold up the PR, but while reviewing I noticed a few related things worth flagging.

as_json() silently drops the result key when it's None

This is the real systemic issue. The fix closes one path to result=None, but payload.py:236-247 will silently omit the "result" key for any code path that leaves result unset:

if isinstance(self.result, TestResultPassed):
    attrs["result"] = "passed"
if isinstance(self.result, TestResultFailed):
    attrs["result"] = "failed"
    ...
if isinstance(self.result, TestResultSkipped):
    attrs["result"] = "skipped"
# None → key is just absent

A small safety net here would close off the entire class of bugs, not just this instance:

if "result" not in attrs:
    logger.warning("Test %s has no result set", self.name)
    attrs["result"] = "unknown"

Subtests can also leave result=None

Passing/skipped subtests intentionally don't set a result — the design relies on the parent's call-phase report arriving later. If that report is ever lost (plugin conflict, xdist race, crash), the test ships with result=None and hits the same downstream issue. The as_json() safety net above would cover this too.

finalize_test doesn't validate result before shipping

finalize_test() moves tests to the payload without checking if result was set. A warning log here would make future occurrences visible instead of silent.

Minor: if/if/if in update_test_result

The three outcome checks are independent if statements rather than if/elif/elif. Works fine today since pytest outcomes are mutually exclusive, but elif would make that invariant explicit.

None of these are blockers — the fix as-is solves the reported issue. The as_json() fallback is the one I'd most advocate for as a follow-up since it's a one-line safety net against the whole category.

@jameshill @nprizal when is this change going to be released to pypi?

Hi @jasonwbarnett, I will release this change today.

Hi @jasonwbarnett, I have released v1.4.2 that includes this change.