FabledScribe/tests/test_services_plugin_context.py

from unittest.mock import AsyncMock, MagicMock, patch

import pytest
from scribe.services import plugin_context as pc_module
from scribe.services import retrieval_surfaces as rs
from scribe.services.lessons import LESSON_NOTE_TYPE
from tests.helpers import fake_note, writepath_cfg


pytestmark = pytest.mark.usefixtures("_no_supersession")




# ─── knowledge auto-inject (Path A) ──────────────────────────────────────────


@pytest.mark.asyncio
async def test_get_autoinject_config_defaults_and_clamps():
    from scribe.services import plugin_context as pc

    # No settings stored → defaults.
    with patch.object(pc, "get_setting", AsyncMock(side_effect=lambda uid, k, d: d)), \
         patch.object(rs, "get_setting", AsyncMock(side_effect=lambda uid, k, d="": d)):
        cfg = await pc.get_autoinject_config(1)
    assert cfg == {
        "enabled": pc.AUTOINJECT_DEFAULT_ENABLED,
        "threshold": pc.AUTOINJECT_DEFAULT_THRESHOLD,
        "top_k": pc.AUTOINJECT_DEFAULT_TOP_K,
    }

    # Out-of-range values are clamped; top_k capped at the hard ceiling.
    stored = {
        pc.AUTOINJECT_ENABLED_KEY: "false",
        pc.AUTOINJECT_THRESHOLD_KEY: "5",
        pc.AUTOINJECT_TOP_K_KEY: "999",
    }
    # The switch comes from plugin_context, the two numbers from the registry.
    def _side(uid, k, d=""):
        return stored.get(k, d)

    with patch.object(pc, "get_setting", AsyncMock(side_effect=_side)), \
         patch.object(rs, "get_setting", AsyncMock(side_effect=_side)):
        cfg = await pc.get_autoinject_config(1)
    assert cfg["enabled"] is False
    assert cfg["threshold"] == 1.0
    assert cfg["top_k"] == pc._AUTOINJECT_MAX_TOP_K


@pytest.mark.asyncio
async def test_build_autoinject_hint_disabled_returns_empty_and_skips_search():
    from scribe.services import plugin_context as pc
    search = AsyncMock()
    with patch.object(pc, "get_autoinject_config",
                      AsyncMock(return_value={"enabled": False, "threshold": 0.55, "top_k": 3})), \
         patch.object(pc, "semantic_search_notes", search), \
         patch.object(pc, "record_retrieval", MagicMock()):
        out = await pc.build_autoinject_hint(1, "anything")
    assert out["context"] == "" and out["note_ids"] == []
    search.assert_not_called()  # disabled → no retrieval at all


@pytest.mark.asyncio
async def test_build_autoinject_hint_titles_only_with_margin_gate():
    from scribe.services import plugin_context as pc
    # top=0.80; 0.74 within band (0.10), 0.61 outside → dropped.
    hits = [(0.80, fake_note(id=11, title="Pool sizing decision", user_id=1)),
            (0.74, fake_note(id=22, title="run_maintenance thresholds", user_id=1)),
            (0.61, fake_note(id=33, title="unrelated-ish", user_id=1))]
    rec = MagicMock()
    with patch.object(pc, "get_autoinject_config",
                      AsyncMock(return_value={"enabled": True, "threshold": 0.55, "top_k": 3})), \
         patch.object(pc, "semantic_search_notes", AsyncMock(return_value=hits)), \
         patch.object(pc, "record_retrieval", rec):
        out = await pc.build_autoinject_hint(1, "postgres pool", project_id=2,
                                             exclude_ids=[99])
    # Margin gate kept the top two, dropped the straggler.
    assert out["note_ids"] == [11, 22]
    assert '#11 [note] "Pool sizing decision" (0.80)' in out["context"]
    assert "#33" not in out["context"]
    # Title-first: no body text, ever.
    assert "get_note(id)" in out["context"]
    # Telemetry fired for BOTH retrievals this path runs: the scored menu and
    # the reuse-slot query competing against it. The slot's query used to be
    # the one unlogged retrieval on this path — the hit it displaced was in
    # retrieval_logs, the query that displaced it was not (#2463).
    sources = [c.kwargs["source"] for c in rec.call_args_list]
    assert sources == ["auto_inject", "reuse_slot", "lesson_slot"]


@pytest.mark.asyncio
async def test_build_autoinject_hint_blank_query_returns_empty():
    from scribe.services import plugin_context as pc
    search = AsyncMock()
    with patch.object(pc, "get_autoinject_config",
                      AsyncMock(return_value={"enabled": True, "threshold": 0.55, "top_k": 3})), \
         patch.object(pc, "semantic_search_notes", search):
        out = await pc.build_autoinject_hint(1, "   ")
    assert out["context"] == ""
    search.assert_not_called()




@pytest.mark.asyncio
async def test_build_session_context_includes_project_when_scoped():
    # design_system_id explicitly None: a bare MagicMock would hand back a truthy
    # auto-attribute and send this through the design branch, which is the
    # opposite of what this test is about.
    project = MagicMock(id=2, title="FabledScribe", goal="ship it",
                        design_system_id=None)
    with patch("scribe.services.plugin_context.projects_svc.get_project",
               AsyncMock(return_value=project)), \
         patch("scribe.services.plugin_context.notes_svc.list_notes",
               AsyncMock(return_value=([], 4))):
        from scribe.services.plugin_context import build_session_context
        out = await build_session_context(user_id=7, project_id=2)

    assert out["project"] == {"id": 2, "title": "FabledScribe"}
    assert "## Active project: FabledScribe (id 2)" in out["context"]
    assert "Open todo tasks: 4" in out["context"]
    # No design system on the project -> no design block at all. An install with
    # none is the ordinary case, not a degraded one.
    assert "## Design system" not in out["context"]
    # Live state only (decision #4027): how to work with Scribe is the
    # using-scribe skill's to say. A restated reflex here is a copy that drifts.
    assert 'content_type="rule"' not in out["context"]
    assert "Reflex:" not in out["context"]


def test_a_short_goal_is_shown_whole():
    from scribe.services.plugin_context import _goal_line
    assert _goal_line("ship it", 2) == "Goal: ship it"
    assert _goal_line("", 2) == ""


def test_a_long_goal_is_cut_at_a_word_and_says_where_the_rest_is():
    """#4036: a raw slice ended mid-word with nothing marking the cut, so a
    reader took half a sentence for the whole goal."""
    from scribe.services.plugin_context import _GOAL_CHARS, _goal_line
    goal = "make the record reach the next session\nso a solution is recalled " * 10
    line = _goal_line(goal, 2)
    shown = line.removeprefix("Goal: ").split(" (full goal:")[0]
    assert shown.endswith("…") and len(shown) <= _GOAL_CHARS
    # The cut lands between words: what precedes the ellipsis is a whole word.
    assert shown[:-1].rstrip().split()[-1] in goal.split()
    assert "\n" not in line
    assert line.endswith("(full goal: `enter_project(2)`)")


def test_an_unbroken_goal_still_shows_its_start():
    from scribe.services.plugin_context import _GOAL_CHARS, _goal_line
    shown = _goal_line("x" * 500, 2).removeprefix("Goal: ").split(" (full goal:")[0]
    assert shown == "x" * (_GOAL_CHARS - 1) + "…"


@pytest.mark.asyncio
async def test_build_session_context_pushes_the_projects_design_system():
    """The gap this closes: a design system had no push channel, so its
    standards reached a session only if the agent already knew to go looking —
    the same silent failure as a token nobody declares."""
    project = MagicMock(id=2, title="App", goal="", design_system_id=9)
    design = {
        "id": 9, "title": "App kit", "description": "",
        "inherits_from": ["House"],
        "guidance": [], "token_count": 95,
        "token_groups": ["accent", "surface", "type"],
    }
    with patch("scribe.services.plugin_context.projects_svc.get_project",
               AsyncMock(return_value=project)), \
         patch("scribe.services.plugin_context.notes_svc.list_notes",
               AsyncMock(return_value=([], 0))), \
         patch("scribe.services.plugin_context.design_systems_svc.design_context",
               AsyncMock(return_value=design)):
        from scribe.services.plugin_context import build_session_context
        out = await build_session_context(user_id=7, project_id=2)

    ctx = out["context"]
    assert "## Design system: App kit (id 9) (inherits House)" in ctx
    assert "95 tokens across accent, surface, type" in ctx
    # A pointer to the values, never the values themselves — a hundred token
    # declarations would crowd out the context they are meant to inform. The
    # summary carries counts and group NAMES only, which is why design_context
    # returns those rather than the resolved tokens.
    assert "resolve_design_system(9)" in ctx
    assert "get_design_system_stylesheet(9)" in ctx
    # The prose pointer names the call that has the MERGED guidance, not
    # enter_project, which carries only the summary now (#4045).
    assert "`get_design_system(9)` → `resolved_guidance`" in ctx


@pytest.mark.asyncio
async def test_build_session_context_survives_an_unreadable_design_system():
    """design_context returns None when the caller may not read the system.
    That must degrade to "no design block", not to a crash that costs the
    session its rules too."""
    project = MagicMock(id=2, title="App", goal="", design_system_id=9)
    with patch("scribe.services.plugin_context.projects_svc.get_project",
               AsyncMock(return_value=project)), \
         patch("scribe.services.plugin_context.notes_svc.list_notes",
               AsyncMock(return_value=([], 0))), \
         patch("scribe.services.plugin_context.design_systems_svc.design_context",
               AsyncMock(return_value=None)):
        from scribe.services.plugin_context import build_session_context
        out = await build_session_context(user_id=7, project_id=2)

    assert "## Design system" not in out["context"]
    assert "## Active project: App (id 2)" in out["context"]


@pytest.mark.asyncio
async def test_build_session_context_unbound_repo_emits_bind_hint():
    from scribe.services.plugin_context import build_session_context
    out = await build_session_context(
        user_id=7, project_id=0, unbound_repo="host/owner/repo",
    )

    ctx = out["context"]
    assert out["project"] is None
    assert "## Repository not yet bound" in ctx
    assert 'bind_repo(repo_url="host/owner/repo"' in ctx
    # No project block when unbound.
    assert "## Active project" not in ctx


@pytest.mark.asyncio
async def test_a_project_id_that_does_not_resolve_is_reported_not_dropped():
    """A `.scribe` marker names a project directly (#4085), so for the first
    time a caller arrives holding a pointer it BELIEVES in. If the id is for
    another instance, or names a deleted project, the session has to be told —
    it cannot infer it from an absence.

    This used to render nothing whatsoever: the branch hung off `if project_id`
    as an `elif`, so an id that was sent and failed took the outer arm, found
    no project, and fell out of the block having said nothing at all.
    """
    from scribe.services.plugin_context import build_session_context
    with patch("scribe.services.plugin_context.projects_svc.get_project",
               AsyncMock(return_value=None)):
        out = await build_session_context(user_id=7, project_id=41)

    ctx = out["context"]
    assert out["project"] is None
    assert "## Project 41 could not be loaded" in ctx
    assert "list_projects" in ctx
    # Not mistaken for the repo case, which has a different remedy.
    assert "## Repository not yet bound" not in ctx
    assert "No Scribe project is bound" not in ctx


@pytest.mark.asyncio
async def test_build_process_manifest_renders_stub_specs():
    items = [
        {"id": 5, "title": "Drift Audit", "tags": [], "snippet": "Find drifted docs."},
        {"id": 9, "title": "DRY Pass", "tags": [], "snippet": ""},
    ]
    with patch("scribe.services.plugin_context.knowledge_svc.query_knowledge",
               AsyncMock(return_value=(items, 2))):
        from scribe.services.plugin_context import build_process_manifest
        out = await build_process_manifest(user_id=7)

    assert out["total"] == 2
    drift = out["processes"][0]
    assert drift["id"] == 5
    assert drift["name"] == "Drift Audit"
    assert drift["slug"] == "drift-audit"          # kebab-cased
    assert "Drift Audit" in drift["description"]   # auto-surface trigger
    assert "Find drifted docs." in drift["description"]  # preview folded in
    # No-snippet process still gets a usable description.
    assert "DRY Pass" in out["processes"][1]["description"]


@pytest.mark.asyncio
async def test_build_process_manifest_dedupes_slugs_and_skips_blank_titles():
    items = [
        {"id": 1, "title": "My Process", "tags": [], "snippet": "a"},
        {"id": 2, "title": "my process", "tags": [], "snippet": "b"},  # same slug
        {"id": 3, "title": "   ", "tags": [], "snippet": "skip me"},   # blank title
    ]
    with patch("scribe.services.plugin_context.knowledge_svc.query_knowledge",
               AsyncMock(return_value=(items, 3))):
        from scribe.services.plugin_context import build_process_manifest
        out = await build_process_manifest(user_id=7)

    slugs = [p["slug"] for p in out["processes"]]
    assert slugs == ["my-process", "my-process-2"]  # collision suffixed with id
    assert out["total"] == 2                          # blank-title entry dropped


@pytest.mark.asyncio
async def test_build_process_manifest_truncates_long_preview():
    items = [{"id": 1, "title": "Big", "tags": [], "snippet": "x" * 500}]
    with patch("scribe.services.plugin_context.knowledge_svc.query_knowledge",
               AsyncMock(return_value=(items, 1))):
        from scribe.services.plugin_context import build_process_manifest
        out = await build_process_manifest(user_id=7)

    assert "…" in out["processes"][0]["description"]
    assert "x" * 500 not in out["processes"][0]["description"]


@pytest.mark.asyncio
async def test_build_session_context_caps_length():
    """The cap still binds, and now has to be provoked rather than tripped.

    This used to hand the block 200 long rule titles, because the preload made
    overflow the easy case. Milestone 394 removed that block, so nothing this
    function assembles on its own is big enough any more — which is a reason
    to drive the cap directly, not a reason to drop it. The project and design
    blocks are still unbounded in principle, and the hook passes this text
    through verbatim.

    Patching the cap rather than manufacturing 9,000 characters keeps the test
    about the TRUNCATION PATH — that it cuts, and that it says it cut — which
    is the part a reader depends on. The unbound-repo hint supplies the text:
    since milestone 410 the block carries live state only, and a bare session
    is a one-liner.
    """
    from scribe.services import plugin_context as pc

    with patch.object(pc, "_MAX_CHARS", 60):
        out = await pc.build_session_context(user_id=7, unbound_repo="host/owner/repo")

    assert len(out["context"]) <= 60 + 20  # cap + truncation note
    assert "truncated" in out["context"], (
        "the block was cut without saying so — a reader cannot tell a "
        "truncated context from a short one"
    )


# --- the reuse slot (#2246) --------------------------------------------------

_CFG = {"enabled": True, "threshold": 0.55, "top_k": 3}


def _asked_for_reuse(calls: list[dict]) -> bool:
    """Did the reuse slot issue its reserved query on this run?"""
    return any(
        tuple(c.get("note_type") or ()) == pc_module._REUSE_KINDS for c in calls
    )


async def _autoinject(main_hits, reuse_hits, cfg=None, lesson_hits=None):
    """Run build_autoinject_hint with each semantic query stubbed by the kinds
    it asks for: the unscoped pool, the reserved reuse query, and the reserved
    lesson query (milestone 385 step 5).

    ROUTED ON THE REQUESTED KINDS, not on call order, and that is the point of
    the helper. Order-keyed stubbing was fine while there was one reserved
    slot; with two it makes every test in this section depend on which slot
    runs first, so adding a third would silently hand one slot another's
    candidate list and the tests would still pass.
    """
    calls: list[dict] = []

    async def fake_search(*_a, **kw):
        calls.append(kw)
        kinds = kw.get("note_type") or ()
        if LESSON_NOTE_TYPE in kinds:
            return lesson_hits or []
        if kinds:
            return reuse_hits
        return main_hits

    with patch("scribe.services.plugin_context.get_autoinject_config",
               AsyncMock(return_value=dict(cfg or _CFG))), \
         patch("scribe.services.plugin_context.semantic_search_notes",
               AsyncMock(side_effect=fake_search)), \
         patch("scribe.services.plugin_context.record_retrieval", MagicMock()), \
         patch("scribe.services.plugin_context.record_surfaced", MagicMock()), \
         patch("scribe.services.plugin_context.owner_names_for",
               AsyncMock(return_value={})):
        from scribe.services.plugin_context import build_autoinject_hint
        out = await build_autoinject_hint(1, "write a debounce helper")
    return out, calls


@pytest.mark.asyncio
async def test_a_snippet_takes_the_last_slot_when_none_won_on_score():
    """The measured failure: a prompt asking for a helper returned three project
    records ABOUT building the retrieval system, and zero snippets. Scribe's own
    records are about software work, so they share vocabulary with any coding
    prompt while answering none of them."""
    main = [(0.66, fake_note(id=1, title="Step 3: title-first auto-inject", user_id=1)),
            (0.65, fake_note(id=2, title="Task-reminder dedup query crashes", user_id=1, is_task=True)),
            (0.64, fake_note(id=3, title="Drafter hardening · write-path trigger", user_id=1, is_task=True))]
    reuse = [(0.58, fake_note(id=9, title="debounce — collapse rapid calls", user_id=1, note_type="snippet"))]

    out, calls = await _autoinject(main, reuse)

    assert out["note_ids"] == [1, 2, 9]        # last slot displaced, not the first
    assert "#9" in out["context"] and "[snippet]" in out["context"]
    # The reserved query is scoped to the reuse kinds and asks for exactly one.
    assert calls[1]["note_type"] == ("snippet", "process")
    assert calls[1]["limit"] == 1


@pytest.mark.asyncio
async def test_the_reserved_query_is_skipped_when_a_snippet_already_won():
    """No second query, and no slot spent twice, when ranking already did the
    right thing — the fix must be invisible in the case it isn't needed."""
    main = [(0.81, fake_note(id=9, title="debounce helper", user_id=1, note_type="snippet")),
            (0.80, fake_note(id=1, title="some task", user_id=1, is_task=True))]

    out, calls = await _autoinject(main, [])

    # WHICH query ran, not how many. A count here is a claim about every
    # reserved slot on this path at once, so it fails the day an unrelated one
    # is added — and the thing being tested is that THIS slot stood down.
    assert not _asked_for_reuse(calls)
    assert out["note_ids"] == [9, 1]


@pytest.mark.asyncio
async def test_a_weak_snippet_does_not_buy_the_slot():
    """The reserved hit skips the MARGIN band — that band is what snippets lose
    to — but never the threshold. Silence stays the default; a slot spent on an
    irrelevant snippet is how a menu teaches people to ignore it."""
    main = [(0.66, fake_note(id=1, title="a task", user_id=1, is_task=True))]

    out, calls = await _autoinject(main, [])     # threshold returned nothing

    assert out["note_ids"] == [1]
    assert _asked_for_reuse(calls)               # it asked, and got nothing


@pytest.mark.asyncio
async def test_the_reserved_hit_is_not_held_to_the_margin_band():
    """0.58 is 0.08 below the top hit. Under the band it would survive; the point
    is that it must survive even when it wouldn't — a snippet losing to a
    same-vocabulary project record by a wide margin is the whole bug."""
    main = [(0.90, fake_note(id=1, title="a task", user_id=1, is_task=True))]
    reuse = [(0.58, fake_note(id=9, title="debounce", user_id=1, note_type="snippet"))]

    out, _calls = await _autoinject(main, reuse)

    assert 9 in out["note_ids"]


@pytest.mark.asyncio
async def test_a_process_counts_as_reuse_too():
    """A stored process answers 'how do we do X here' the same way a snippet
    answers 'what do we already have' — both lose to the same project records."""
    main = [(0.70, fake_note(id=1, title="a task", user_id=1, is_task=True))]
    reuse = [(0.60, fake_note(id=8, title="DRY pass process", user_id=1, note_type="process"))]

    out, _ = await _autoinject(main, reuse)
    assert 8 in out["note_ids"]

    # …and one already on the menu suppresses the reserved query.
    out2, calls2 = await _autoinject(
        [(0.70, fake_note(id=8, title="DRY pass process", user_id=1, note_type="process"))], [])
    assert not _asked_for_reuse(calls2)


# --- write-path widened beyond snippets (#2246, the mirror half) -------------

@pytest.mark.asyncio
async def test_write_path_semantic_arm_asks_for_experience_not_just_snippets():
    """The inverse of auto-inject's mistake. This arm was snippets-only, so an
    issue saying "we tried this and it deadlocked" could never reach the moment
    that code was about to be written — arguably the better prior art, because
    it says what NOT to do."""
    from scribe.services import plugin_context as pc

    hits = [(0.72, fake_note(id=9, title="debounce helper", user_id=1, note_type="snippet")),
            (0.70, fake_note(id=7, title="Debounce dropped the trailing call", user_id=1, is_task=True, task_kind="issue"))]
    search = AsyncMock(return_value=hits)
    rec = MagicMock()
    with patch.object(pc, "get_writepath_config",
                      AsyncMock(return_value=writepath_cfg(threshold=0.6))), \
         patch.object(pc.snippets_svc, "list_snippets",
                      AsyncMock(return_value=([], 0))), \
         patch.object(pc, "semantic_search_notes", search), \
         patch.object(pc, "record_retrieval", rec), \
         patch.object(pc, "record_surfaced", MagicMock()), \
         patch.object(pc, "owner_names_for", AsyncMock(return_value={})), \
         patch.object(pc, "concept_query", MagicMock(return_value="debounce a callback")):
        out = await pc.build_write_path_hint(
            1, "src/utils/debounce.ts", code="x" * 400,
        )

    kw = search.await_args.kwargs
    assert kw["note_type"] == ("snippet", "note", LESSON_NOTE_TYPE)
    # An open to-do resembling the code answers nothing; an ISSUE carries a root
    # cause and a NOTE carries durable knowledge. Only the todo is excluded.
    assert kw["task_kind"] == "issue"
    # Telemetry must not claim this was a notes-only retrieval any more.
    assert rec.call_args.kwargs["is_task"] is None


@pytest.mark.asyncio
async def test_write_path_labels_a_non_snippet_hit_with_its_kind():
    """An unlabelled issue on this menu reads as "here is code to reuse", which
    is the opposite of what it says. A snippet stays unlabelled — it is the
    menu's default and the header's default reading."""
    from scribe.services import plugin_context as pc

    hits = [(0.72, fake_note(id=9, title="debounce helper", user_id=1, note_type="snippet")),
            (0.71, fake_note(id=7, title="Debounce dropped the trailing call", user_id=1, is_task=True, task_kind="issue"))]
    with patch.object(pc, "get_writepath_config",
                      AsyncMock(return_value=writepath_cfg(threshold=0.6))), \
         patch.object(pc.snippets_svc, "list_snippets",
                      AsyncMock(return_value=([], 0))), \
         patch.object(pc, "semantic_search_notes", AsyncMock(return_value=hits)), \
         patch.object(pc, "record_retrieval", MagicMock()), \
         patch.object(pc, "record_surfaced", MagicMock()), \
         patch.object(pc, "owner_names_for", AsyncMock(return_value={})), \
         patch.object(pc, "concept_query", MagicMock(return_value="debounce a callback")):
        out = await pc.build_write_path_hint(
            1, "src/utils/debounce.ts", code="x" * 400,
        )

    ctx = out["context"]
    # The issue says what it is — and, since #4154, where it stands: a piece of
    # prior art offered as "already tried" reads differently when it is still open.
    assert "· issue (todo)]" in ctx
    assert '[similar 0.72] "debounce helper"' in ctx   # the snippet does not
    # The header now names the right opener for each kind.
    assert "get_task(id)" in ctx and "get_snippet(id)" in ctx


# ── The config stand-in cannot fall behind the real one (#4214) ───────────

@pytest.mark.asyncio
async def test_the_config_stand_in_carries_every_key_the_real_one_does():
    """THE GUARD `writepath_cfg`'s DOCSTRING ALREADY CLAIMED AND DID NOT HAVE.

    Three arms read their numbers out of that dict inside a fail-open
    `except`, so a missing key does not raise where anyone can see it — the
    arm silently becomes a no-op, which is indistinguishable from the arm
    working and finding nothing. The helper derives its SURFACE keys from the
    registry to prevent exactly that, and then #4214 added a key that is
    deliberately not a surface: the whole derivation missed it, ten tests went
    red at once, and the diagnosis cost a CI round.

    Asserting the KEY SETS match, not the values: the stand-in exists to let a
    test set different numbers.
    """
    from unittest.mock import AsyncMock, patch

    from scribe.services import plugin_context as pc
    from tests.helpers import writepath_cfg

    with patch.object(pc, "get_setting", AsyncMock(return_value="0.6")), \
            patch.object(pc, "floor_for", AsyncMock(return_value=0.6)), \
            patch.object(pc, "budget_for", AsyncMock(return_value=3)):
        real = await pc.get_writepath_config(1)

    assert set(writepath_cfg()) == set(real), (
        "tests/helpers.writepath_cfg has fallen behind get_writepath_config; "
        "a key the real config has and the stand-in does not turns an arm "
        "into a silent no-op under test"
    )