portfolio-optimiser/tests/test_checker_gate_loadbearing.py

"""Step 3/4 load-bearing seam (målbilde §2/§6/§7): an explicit checker REJECT MUST gate.

The gap (fot-i-bakken, verified in code): the GroupChat checker critiqued into the void —
``output_from=[proposer]`` surfaced only the proposer, so an explicit checker rejection was
ignored and the ONLY blocking gate was the deterministic validator (on the *numbers*). Fase 3
surfaces the checker verdict and makes an explicit ``VERDICT: REJECT`` block an otherwise-
validated proposal — qualitative falsification on the *reasoning*, distinct from the validator
on the *numbers* (målbilde §2 step 4).

These two tests are a load-bearing PAIR, not a smoke test (per the Fase-2 green-but-dead trap):
- the positive test uses a VALIDATOR-VALID proposer, so the ONLY possible rejecter is the
  checker; it asserts the checker's reason propagates into ``outcome.reason`` AND that provenance
  stays honest (``validator_decision == "validated"``). It goes RED on EITHER detach: revert
  ``output_from=agents`` to proposer-only, OR drop the run.py checker override.
- the approve test is the causality control: the SAME valid proposer with a checker APPROVE
  validates normally — proving the rejection above is CAUSED by the checker verdict, not the
  fixture.
"""

from __future__ import annotations

from collections.abc import Callable
from pathlib import Path

from agent_framework import BaseChatClient
from conftest import SyntheticUsageChatClient

from portfolio_optimiser.run import run_project
from portfolio_optimiser.validator import Rejection, ValidatedProposal

BUNDLE_DIR = Path(__file__).resolve().parents[1] / "shared" / "examples" / "bygg-energi-mikro"

# A VALIDATOR-VALID BYGG-KONTOR-NORD proposal (same shape as the Step-1 test): affected total
# 300000 x 1.0; no assumptions -> degenerate Monte Carlo P90 = 0.30 x 300000 = 90000 >= claimed
# 30000 -> validates on the first attempt. So in the reject test the ONLY possible rejecter is
# the checker, never the validator (closes the green-but-dead trap).
_VALID_PROPOSER_REPLY = (
    '{"measure":"LED-retrofit av kontorbelysning","affected_items":'
    '[{"code":"ENERGI-TOTAL-EL","quantity":300000,"unit_cost":1.0}],"claimed_saving_nok":30000}'
)
_VERDICT_INPUT = {"decision": "approved", "rationale": "expert reviewed (sim)"}
# A unique reason substring: it can only reach outcome.reason if the checker's output actually
# reached the gate (the "third assertion" that makes the pair load-bearing, not green-but-dead).
_REJECT_REASON = "payback exceeds horizon (sim-unique a1b2c3)"


def _role_factory(proposer_reply: str, checker_reply: str) -> Callable[[str], BaseChatClient]:
    """A role-aware synthetic factory: the checker speaks its verdict, the proposer its proposal.
    The existing make_*_client_factory fixtures are role-agnostic, so the gate needs this."""

    def factory(role: str) -> BaseChatClient:
        return SyntheticUsageChatClient(
            default_reply=checker_reply if role == "checker" else proposer_reply
        )

    return factory


async def test_explicit_checker_reject_gates_a_validated_proposal() -> None:
    """LOAD-BEARING: an explicit checker REJECT blocks an otherwise-validated proposal. Goes RED
    if ``output_from`` drops the checker OR the run.py checker override is removed."""
    factory = _role_factory(_VALID_PROPOSER_REPLY, f"VERDICT: REJECT - {_REJECT_REASON}")

    result = await run_project(
        "BYGG-KONTOR-NORD",
        "local",
        docs_dir=str(BUNDLE_DIR),
        bundle_dir=str(BUNDLE_DIR),
        verdict_input=_VERDICT_INPUT,
        client_factory=factory,
    )

    assert isinstance(result.outcome, Rejection), (
        "checker said REJECT but the proposal was not gated — the checker verdict is ignored"
    )
    assert _REJECT_REASON in result.outcome.reason, (
        "the checker's reason did not propagate into the outcome — its output never reached the gate"
    )
    # Provenance honesty: the VALIDATOR passed (the numbers are feasible); only the checker
    # rejected. validator_decision must reflect the numbers, never conflate the two falsifiers.
    assert result.provenance.validator_decision == "validated", (
        "provenance conflates the two falsifiers — validator_decision must reflect the numbers only"
    )
    assert result.checker_verdict == "reject"


async def test_checker_approve_lets_a_validated_proposal_through() -> None:
    """CAUSALITY CONTROL: the SAME valid proposer with a checker APPROVE validates normally —
    proving the rejection above is caused by the checker verdict, not the fixture's mere shape."""
    factory = _role_factory(_VALID_PROPOSER_REPLY, "VERDICT: APPROVE")

    result = await run_project(
        "BYGG-KONTOR-NORD",
        "local",
        docs_dir=str(BUNDLE_DIR),
        bundle_dir=str(BUNDLE_DIR),
        verdict_input=_VERDICT_INPUT,
        client_factory=factory,
    )

    assert isinstance(result.outcome, ValidatedProposal)
    assert result.checker_verdict == "approve"