Wire 0050 failure-isolation conformance fixtures

[chris-colinsky]

Summary

Wire proposal 0050's failure-isolation conformance fixtures (pipeline-utilities/058-063) into the conformance harness, validating the §6.3 FailureIsolationMiddleware behavior against the spec fixtures (previously covered by unit tests only). This is the third v0.14.0 piece, after the cause-fidelity behavior fix (#153) and ahead of the spec-pin bump to v0.55.0.

Test/manifest only, no src/ changes.

What changed

• A failure_isolation middleware directive (a directives.py spec + a _build_middleware branch constructing the real FailureIsolationMiddleware) and the expected_failure_isolation_event assertion, backed by a FailureIsolatedEvent capture observer.
• Variant conventions for the fixtures: callable degraded_update (a {{ state.x }} template render), matches_category predicate, and the on_caught state-side-channel (overlaid onto final_state, since the callback can't write graph state directly).
• The raises node directive accepts the {message, exception_kind} shape (fixture 063).
• Un-defers 058-063 from parsing and execution.

Scope notes

• 061 is execution-deferred. python's FailureIsolatedEvent.attempt_index in the three-piece composition is the node-level baseline (0), while fixture 061 (and §6.3's lineage-correlation prose) expect the final retry attempt (1). That reconciliation is in progress with spec; 061 un-defers once it resolves and python's attempt_index is corrected if needed.
• The call-level-retry fixtures (llm-provider/056-058) stay deferred. They assert the per-attempt LLM span surface that 0050 deferred (decision (b); partial in the manifest), so they remain queued until a future LlmRetryAttemptEvent cycle.

Validation

• Full conformance suite: 593 passed, 251 skipped, 0 failed (exercises the shared-harness changes across all capabilities).
• The five failure-isolation fixtures (058/059/060/062/063) execute and pass; ruff + pyright clean; conformance-manifest guard OK.

[Copilot]

Pull request overview

Wires Wire proposal 0050 failure-isolation conformance fixtures (pipeline-utilities/058–063) into the Python conformance harness by adding fixture directive parsing, middleware construction, and FailureIsolatedEvent assertions (with 061 still execution-deferred due to the attempt_index discrepancy).

Changes:

• Add a failure_isolation middleware directive model and runtime construction path, including predicate + degraded_update callable encoding and an on_caught side-channel overlay.
• Capture and assert FailureIsolatedEvent via new expected_failure_isolation_event / no_failure_isolation_event expected-block keys.
• Extend the raises node directive to accept {message, exception_kind} for fixture 063 and un-defer parsing/execution for 058/059/060/062/063.

Reviewed changes

Copilot reviewed 6 out of 6 changed files in this pull request and generated 1 comment.

Show a summary per file

File	Description
tests/conformance/test_pipeline_utilities.py	Runs pipeline-utilities 058–063, builds FailureIsolationMiddleware from fixture config, captures FailureIsolatedEvent, and asserts expected event/no-event plus on_caught overlay.
tests/conformance/test_fixture_parsing.py	Updates parsing deferrals: keeps llm-provider/056–058 deferred, removes pipeline-utilities/058–063 from parsing deferral notes.
tests/conformance/harness/expectations.py	Adds expected-block fields for failure-isolation assertions and parses 061’s expected_attempt_events.
tests/conformance/harness/directives.py	Adds failure_isolation middleware directive schema and expands raises to allow dict shape.
tests/conformance/adapter.py	Implements {message, exception_kind} support for raises nodes.
conformance.toml	Updates proposal 0050 notes to reflect fixture wiring status and 061’s pending attempt_index reconciliation.

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