portfolio-optimiser/tests/test_frontmatter_unquote_loadbearing.py

"""Kø-(a)/(i) — ONE unquoting rule for frontmatter scalars, and it renders the read-context.

Two rules existed. ``verdicts._unquote`` (``.strip().strip('"').strip("'").strip()``) unquoted the
structural key correctly; ``okf.bundle_context`` unquoted a title with a bare ``.strip('"')``. The
weaker one sat in the path that becomes the agent's read-context and that the commons-owned
nav-goldens byte-compare. Measured before the fix:

    title: "  Spaced  "  ->  ``## concept:   Spaced  ``   (the whitespace half — what (a) named)
    title: 'Single'      ->  ``## concept: 'Single'``     (single quotes rendered verbatim)

Both are frontmatter YAML writes any hand-authoring curator may make, and both reach the model.
This is the (p) defect class — two copies of one conversion, the drifted copy where it matters —
so the fix is the same shape: ONE source, owned by the module that owns ``parse_frontmatter``.

Detach points, each its own test: weaken the renderer back to ``.strip('"')`` -> RED; reintroduce
a private copy in ``verdicts`` -> RED. The control proves the gate covers ground the nav-goldens
do not: every golden title is double-quoted with no inner whitespace, so the goldens stay byte-
identical under BOTH rules and can never have caught this.
"""

from __future__ import annotations

from pathlib import Path

import pytest

from portfolio_optimiser import okf
from portfolio_optimiser import verdicts as verdicts_mod

_GOLDEN_ROOT = Path(__file__).resolve().parents[1] / "shared" / "examples"


def _bundle(tmp_path: Path, title_line: str) -> str:
    """A minimal two-file bundle whose single concept file carries ``title_line`` verbatim."""
    (tmp_path / "index.md").write_text(
        '---\ntype: index\ntitle: "Root"\n---\n\nSummary.\n\n- [A](a.md)\n',
        encoding="utf-8",
    )
    (tmp_path / "a.md").write_text(
        f"---\ntype: concept\n{title_line}\n---\n\nbody a\n", encoding="utf-8"
    )
    return str(tmp_path)


def _heading(bundle_dir: str) -> str:
    ctx = okf.bundle_context(okf.navigate_bundle(bundle_dir))
    return next(line for line in ctx.splitlines() if line.startswith("## "))


@pytest.mark.parametrize(
    ("title_line", "expected"),
    [
        ('title: "  Spaced  "', "## concept: Spaced"),
        ("title: 'Single'", "## concept: Single"),
        ('title: "Plain"', "## concept: Plain"),
        ("title: Bare", "## concept: Bare"),
    ],
)
def test_rendered_title_is_unquoted_and_trimmed(
    tmp_path: Path, title_line: str, expected: str
) -> None:
    """The rendered heading carries the TITLE, not the frontmatter's quoting artifacts.

    Detach point: revert ``bundle_context`` to ``.strip('"')`` -> the first two rows go RED
    (``## concept:   Spaced  `` and ``## concept: 'Single'``). The last two rows are the control
    that the stronger rule did not change the cases that already worked."""
    assert _heading(_bundle(tmp_path, title_line)) == expected


def test_frontmatter_unquoting_has_exactly_one_source() -> None:
    """``verdicts`` must DELEGATE, not carry its own copy — the (p) rule applied to unquoting.

    Identity, not equal behaviour: two implementations that agree today are exactly the state
    this defect class starts from. Reintroduce a private copy in ``verdicts`` -> RED."""
    assert verdicts_mod._unquote is okf.unquote_scalar, (
        "verdicts must delegate to okf.unquote_scalar; a private copy is the defect class"
    )


def test_verdict_structural_key_still_unquotes_after_delegation() -> None:
    """The delegation must be behaviour-identical on the structural key, because ``_mint_id``
    hashes these values — a normalising change would re-key every promoted verdict.

    Not a tautology against the source: the expected values are written out longhand here."""
    assert okf.unquote_scalar('"  Spaced  "') == "Spaced"
    assert okf.unquote_scalar("'Single'") == "Single"
    assert okf.unquote_scalar("  bare  ") == "bare"
    assert okf.unquote_scalar('"18000"') == "18000"


def test_nav_goldens_cannot_have_caught_this() -> None:
    """CONTROL — the commons-owned byte-level fasit is blind to this defect by construction.

    Every golden title is double-quoted with no inner whitespace, so ``.strip('"')`` and
    ``unquote_scalar`` render byte-identically there. If a future golden gains a single-quoted or
    space-padded title this test goes RED and says so: the fasit would then be load-bearing for
    the rule, and this file's claim to cover uncovered ground would no longer hold."""
    titles = [
        line.split(":", 1)[1].strip()
        for path in sorted(_GOLDEN_ROOT.glob("nav-golden-*/**/*.md"))
        for line in path.read_text(encoding="utf-8").splitlines()
        if line.startswith("title:")
    ]
    assert titles, "no golden titles found — the control has lost its subject"
    for raw in titles:
        assert raw.strip('"') == okf.unquote_scalar(raw), (
            f"golden title {raw!r} now discriminates between the two rules — the nav-goldens "
            "have become load-bearing for unquoting, so this control must be re-stated"
        )