# @Test suite for multi-line needs rendered by src-trace, TEST_MULTILINE_RENDER_1, test, [IMPL_LNK_1]
"""``src-trace`` creates a need from every multi-line need of its files (#1885).

Every case builds a copy of ``doc_test/need_id_refs`` (see ``test_need_id_refs``) made
into a git repository, with ``myst-parser`` loaded, ``get_multiline_needs`` on, a host
need ``REQ_HOST`` and a label ``host-label`` in ``index``, and ``src/refs.cpp`` emptied of
its references. A block's body is parsed in the markup it declares, whatever the page's:
the four cells (page markup by body markup) render the same role link, reference, list and literal.
"""

import hashlib
import re
from pathlib import Path
from typing import Any

import myst_parser
import pytest
from sphinx.testing.util import SphinxTestApp
from sphinx.util.parallel import parallel_available

from sphinx_needs_testkit import build_warnings

from .test_need_id_refs import _SHOWS_WARNING_TYPES, _build, _json, _MakeApp, _project
from .test_rediscovery import _touch_later

MYST_MAJOR = int(myst_parser.__version__.split(".")[0])

CONF = """\
extensions = ["sphinx_needs", "sphinx_codelinks", "myst_parser"]
exclude_patterns = ["_build"]
needs_build_json = True
source_suffix = {".rst": "restructuredtext", ".md": "markdown"}
needs_fields = {"priority": {"description": "Priority", "schema": {"type": "integer"}}}
"""

INDEX = """\
Multi-line needs
================

.. toctree::
   :glob:

   *
   sub/*

.. req:: A host need
   :id: REQ_HOST

.. _host-label:

Host label target
-----------------
"""

MULTILINE = """
[codelinks.projects.src.analyse]
get_oneline_needs = true
get_multiline_needs = true
"""

#: the files every case starts from
BASE = {
    "docs/conf.py": CONF,
    "docs/index.rst": INDEX,
    "src/refs.cpp": "// no markers here\n",
}

PAGE_RST = """\
RST page
========

.. src-trace::
   :project: src
   :file: rr.c

.. src-trace::
   :project: src
   :file: rm.c
"""

PAGE_MD = """\
# MyST page

```{src-trace}
:project: src
:file: mr.c
```

```{src-trace}
:project: src
:file: mm.c
```
"""

RST_BODY = """\
 * Body in RST, see :need:`REQ_HOST` and :ref:`host-label`.
 *
 * - bullet one
 * - bullet with ``inline literal``"""

MYST_BODY = """\
 * Body in MyST, see {need}`REQ_HOST` and {ref}`host-label`.
 *
 * - bullet one
 * - bullet with `inline literal`"""


def _cell(name: str, markup: str, body: str) -> str:
    """A source file: a one-line need on line 1, a block opening on line 5."""
    upper = name.upper()
    return f"""\
// @one-line in {name}.c, IMPL_{upper}_ONE, impl, [REQ_HOST]
void f() {{}}

/**
 * @need[{markup}] req: {upper} body
 * :id: REQ_{upper}
 * :links: REQ_HOST, IMPL_{upper}_ONE
 *
{body}
 * @endneed
 */
void g() {{}}
"""


#: the four cells: (source, page, the directive's line on it, the body's markup)
CELLS = {
    "REQ_RR": ("rr.c", "page_rst", 4, ".rst"),
    "REQ_RM": ("rm.c", "page_rst", 8, ".md"),
    "REQ_MR": ("mr.c", "page_md", 3, ".rst"),
    "REQ_MM": ("mm.c", "page_md", 8, ".md"),
}

FOUR_CELLS = {
    "docs/page_rst.rst": PAGE_RST,
    "docs/page_md.md": PAGE_MD,
    "src/rr.c": _cell("rr", "rst", RST_BODY),
    "src/rm.c": _cell("rm", "md", MYST_BODY),
    "src/mr.c": _cell("mr", "rst", RST_BODY),
    "src/mm.c": _cell("mm", "md", MYST_BODY),
}


def _blocks(tmp_path: Path, files: dict[str, str], *, toml_extra: str = "") -> str:
    """The project with ``files`` added; return its commit."""
    return _project(
        tmp_path, files={**BASE, **files}, toml_extra=MULTILINE + toml_extra
    )


def _warning(location: str, message: str, subtype: str) -> str:
    suffix = f" [codelinks.{subtype}]" if _SHOWS_WARNING_TYPES else ""
    return f"{location}: WARNING: {message}{suffix}"


def _multiline(location: str, message: str) -> str:
    return _warning(location, message, "multiline_need")


def _content_html(app: SphinxTestApp, page: str, need_id: str) -> str:
    """The HTML of the content cell of the need ``need_id``."""
    text = Path(app.outdir, page).read_text(encoding="utf-8")
    start = text.index('<td class="need content"', text.index(f'id="{need_id}"'))
    return text[start : text.index("</td>", start)]


def _need(app: SphinxTestApp, need_id: str) -> dict[str, Any] | None:
    return _json(app)["needs"].get(need_id)


def _card(app: SphinxTestApp, page: str, need_id: str) -> str | None:
    """The HTML of the need's table on ``page``, ``None`` without one."""
    html = Path(app.outdir, page).read_text(encoding="utf-8")
    match = re.search(rf'<table class="[^"]*" id="{need_id}"[^>]*>', html)
    return (
        None
        if match is None
        else html[match.start() : html.index("</table>", match.start())]
    )


def _warnings(app: SphinxTestApp) -> list[str]:
    """:func:`build_warnings` without the extension re-registration notes a second
    application in one process logs."""
    return [w for w in build_warnings(app) if "is already registered" not in w]


def test_four_cells_render_in_the_declared_markup(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """An RST and a MyST body, each in an RST and a MyST page: the same role link,
    reference, list and literal in all four; each need recorded at its directive with
    the body's doctype, its links converted, its URLs at the block's open line."""
    commit = _blocks(tmp_path, FOUR_CELLS)
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == []
    for need_id, (source, page, lineno, doctype) in CELLS.items():
        need = _need(app, need_id)
        assert need is not None, need_id
        upper = need_id.removeprefix("REQ_")
        assert {
            key: need[key]
            for key in ("docname", "lineno", "doctype", "links", "is_import")
        } == {
            "docname": page,
            "lineno": lineno,
            "doctype": doctype,
            # Sphinx-Needs keeps a need's links sorted
            "links": [f"IMPL_{upper}_ONE", "REQ_HOST"],
            "is_import": False,
        }, need_id
        assert need["local-url"] == f"src/{source}#L5"
        assert need["remote-url"] == (
            f"https://github.com/example/demo/blob/{commit}/src/{source}#L5"
        )
        html = _content_html(app, f"{page}.html", need_id)
        assert 'href="index.html#REQ_HOST"' in html, need_id
        assert 'href="index.html#host-label"' in html, need_id
        assert '<ul class="simple">' in html, need_id
        assert '<code class="docutils literal notranslate">' in html, need_id
        # no role written in the other markup is left as text
        assert ":need:" not in html, need_id
        assert "{need}" not in html, need_id
        # the source page links the open line back to the need
        source_page = Path(app.outdir, "src", source.replace(".c", ".html"))
        assert (
            f'<a class="viewcode-back" href="../{page}.html#{need_id}">[docs]</a>'
            '<a id="L-5" name="L-5">'
        ) in source_page.read_text(encoding="utf-8"), need_id


#: a second project, ``ts``, beside the fixture's ``src``
TS_PROJECT = """
[codelinks.projects.ts]
remote_url_pattern = "https://github.com/example/demo/blob/{commit}/{path}#L{line}"

[codelinks.projects.ts.source_discover]
src_dir = "../ts"
comment_type = "ts"

[codelinks.projects.ts.analyse]
get_oneline_needs = true
get_multiline_needs = true
"""

TS_FILES = {
    "docs/page_ts.rst": """\
TypeScript page
===============

.. src-trace::
   :project: ts
   :file: handler.ts

.. src-trace::
   :project: ts
   :file: button.tsx
""",
    # a run of // comments, its body in RST, opening on line 4
    "ts/handler.ts": """\
// @handler entry, IMPL_TS_ONE, impl, [REQ_HOST]
export function entry(): void {}

// @need[rst] req: Handler body
// :id: REQ_TS_HANDLER
// :links: REQ_HOST, IMPL_TS_ONE
//
// Body in RST, see :need:`REQ_HOST`.
//
// - item one
// - item two
// @endneed
export function handle(request: Request): Response {
  return new Response();
}
""",
    # a JSDoc block, its body in MyST, opening on line 5
    "ts/button.tsx": """\
// @button entry, IMPL_TSX_ONE, impl, [REQ_HOST]
export const entry = 1;

/**
 * @need[md] req: Button body
 * :id: REQ_TSX_BUTTON
 * :links: REQ_HOST, IMPL_TSX_ONE
 *
 * Body in MyST, see {need}`REQ_HOST`.
 *
 * - item one
 * - item two
 * @endneed
 */
export const LoginButton = () => <button>Log in</button>;
""",
}


def test_typescript_blocks_render(tmp_path: Path, make_app: _MakeApp) -> None:
    """A ``//`` run in a ``.ts`` file and a JSDoc block in a ``.tsx`` file render
    through ``src-trace`` as the C blocks do: each body in its declared markup, the
    need recorded at its directive, its URL at the block's open line."""
    _blocks(tmp_path, TS_FILES, toml_extra=TS_PROJECT)
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == []
    expected = {
        "REQ_TS_HANDLER": ("handler.ts", 4, ".rst", "IMPL_TS_ONE", 4),
        "REQ_TSX_BUTTON": ("button.tsx", 8, ".md", "IMPL_TSX_ONE", 5),
    }
    for need_id, (source, lineno, doctype, one_line, open_line) in expected.items():
        need = _need(app, need_id)
        assert need is not None, need_id
        assert {
            key: need[key] for key in ("docname", "lineno", "doctype", "links")
        } == {
            "docname": "page_ts",
            "lineno": lineno,
            "doctype": doctype,
            # Sphinx-Needs keeps a need's links sorted
            "links": [one_line, "REQ_HOST"],
        }, need_id
        assert need["local-url"] == f"ts/{source}#L{open_line}"
        html = _content_html(app, "page_ts.html", need_id)
        assert 'href="index.html#REQ_HOST"' in html, need_id
        assert '<ul class="simple">' in html, need_id
        assert ":need:" not in html, need_id
        assert "{need}" not in html, need_id


def _at(*parts: str) -> str:
    """A path below the project root as a warning prints it after ``<srcdir>/``: with
    the OS's separators, since Sphinx and docutils print the file's own path."""
    return str(Path(*parts))


def _myst_logged(page: str, source: str, line: int) -> str:
    """Where a warning myst-parser logs itself points, for a body in ``source``:
    myst-parser 5 names the page being read with the body's line, myst-parser 4 the
    body's file with an ``.rst`` suffix (Sphinx-Needs' documented first-slice gap)."""
    if MYST_MAJOR >= 5:
        return f"<srcdir>/{_at('docs', page)}:{line}"
    return f"<srcdir>/{_at('src', source)}.rst:{line}"


def _diagnostics_cell(name: str, markup: str) -> str:
    upper = name.upper()
    if markup == "rst":
        body = " * A bad role :nosuchrole:`x` here.\n *\n * .. nosuchdirective:: arg"
    else:
        body = " * A bad role {nosuchrole}`x` here.\n *\n * ```{nosuchdirective} arg\n * ```"
    return f"""\
// a file with one block, opening on line 3

/**
 * @need[{markup}] spec: {upper} diagnostics
 * :id: SPEC_{upper}
 *
{body}
 * @endneed
 */
void h() {{}}
"""


def test_body_diagnostics_name_the_source_line(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A message about an RST body names the source file and line (absolute: Sphinx
    makes a node's source absolute); myst-parser's own messages about a MyST body name
    the page (myst-parser 5) or ``<source>.rst`` (4), with the source line."""
    _blocks(
        tmp_path,
        {
            "docs/page_rst.rst": PAGE_RST,
            "docs/page_md.md": PAGE_MD,
            "src/rr.c": _diagnostics_cell("rr", "rst"),
            "src/rm.c": _diagnostics_cell("rm", "md"),
            "src/mr.c": _diagnostics_cell("mr", "rst"),
            "src/mm.c": _diagnostics_cell("mm", "md"),
        },
    )
    app = _build(tmp_path, make_app)

    docutils = " [docutils]" if _SHOWS_WARNING_TYPES else ""

    def myst(kind: str) -> str:
        return f" [myst.{kind}]" if _SHOWS_WARNING_TYPES else ""

    def rst(source: str) -> list[str]:
        return [
            f"<srcdir>/{_at('src', source)}:7: ERROR: Unknown interpreted text role "
            f'"nosuchrole".{docutils}',
            f"<srcdir>/{_at('src', source)}:9: ERROR: Unknown directive type "
            '"nosuchdirective".'
            "\n\n.. nosuchdirective:: arg"
            f"{docutils}",
        ]

    def md(page: str, source: str) -> list[str]:
        return [
            f"{_myst_logged(page, source, 7)}: WARNING: Unknown interpreted text role "
            f'"nosuchrole".{myst("role_unknown")}',
            f"{_myst_logged(page, source, 9)}: WARNING: Unknown directive type: "
            f"'nosuchdirective'{myst('directive_unknown')}",
        ]

    assert sorted(build_warnings(app, srcdir=tmp_path)) == sorted(
        [
            *rst("mr.c"),
            *md("page_md.md", "mm.c"),
            *rst("rr.c"),
            *md("page_rst.rst", "rm.c"),
        ]
    )
    for need_id in ("SPEC_RR", "SPEC_RM", "SPEC_MR", "SPEC_MM"):
        assert _need(app, need_id) is not None, need_id


Q3_HEAD = "// @need req: Q3 block\n"
#: an expectation on the need's card on its page rather than on ``needs.json``: ``None``
#: for no card, else a text the card holds
CARD = "<card>"
Q3_BODY = "//\n// Body {{ 1 + 1 }} here.\n// @endneed\nvoid q() {}\n"


@pytest.mark.parametrize(
    ("options", "expected", "warnings"),
    [
        pytest.param(
            [":links: REQ_HOST; REQ_002 | SPEC_001"],
            {"links": ["REQ_002", "REQ_HOST", "SPEC_001"]},
            [],
            id="links_split",
        ),
        pytest.param([":tags: a, b"], {"tags": ["a", "b"]}, [], id="tags_split"),
        pytest.param([":status: open"], {"status": "open"}, [], id="status"),
        pytest.param([":priority: 3"], {"priority": 3}, [], id="typed_field_coerced"),
        pytest.param(
            [":priority: notanint"],
            None,
            [
                (
                    1,
                    "invalid_field_value: multi-line need could not be created: Field "
                    "'priority' is invalid: Cannot convert 'notanint' to integer",
                )
            ],
            id="typed_field_refused",
        ),
        pytest.param(
            [":nosuch: x"],
            {"title": "Q3 block"},
            [
                (
                    3,
                    "multi-line need option 'nosuch' is not an option a multi-line "
                    "need takes: ignored",
                )
            ],
            id="unknown_option_warned",
        ),
        pytest.param([":hide:"], {CARD: None}, [], id="hide_flag"),
        pytest.param(
            [":collapse: true"], {CARD: "target__hide__meta"}, [], id="collapse"
        ),
        pytest.param(
            [":constraints: nosuchconstraint"],
            None,
            [
                (
                    1,
                    "invalid_constraints: multi-line need could not be created: "
                    "Constraints {'nosuchconstraint'} not in 'needs_constraints'.",
                )
            ],
            id="unknown_constraint_refused",
        ),
        pytest.param(
            [":jinja_content: false"],
            {"jinja_content": False, "content": "Body {{ 1 + 1 }} here."},
            [],
            id="jinja_content_false",
        ),
        pytest.param(
            [":jinja_content: true"],
            {"jinja_content": True, "content": "Body 2 here."},
            [],
            id="jinja_content_true",
        ),
        pytest.param(
            [":jinja_content: maybe"],
            None,
            [
                (
                    3,
                    "invalid_option: multi-line need could not be created: Invalid "
                    "value for 'jinja_content' option: not a flag or case-insensitive "
                    "true/false/yes/no",
                )
            ],
            id="jinja_content_refused",
        ),
        pytest.param(
            [":docname: elsewhere", ":lineno: 99"],
            {"docname": "page_q", "lineno": 4},
            [
                (
                    3,
                    "multi-line need option 'docname' is not an option a multi-line "
                    "need takes: ignored",
                ),
                (
                    4,
                    "multi-line need option 'lineno' is not an option a multi-line "
                    "need takes: ignored",
                ),
            ],
            id="computed_keys_warned",
        ),
        pytest.param(
            [":parts: some text"],
            {"parts": {}},
            [
                (
                    3,
                    "multi-line need option 'parts' is not an option a multi-line "
                    "need takes: ignored",
                )
            ],
            id="parts_warned_not_crashing",
        ),
        pytest.param(
            [":arch: some text"],
            {"arch": {}},
            [
                (
                    3,
                    "multi-line need option 'arch' is not an option a multi-line "
                    "need takes: ignored",
                )
            ],
            id="arch_warned",
        ),
        pytest.param(
            [":Status: open", ":TAGS: a, b"],
            {"status": "open", "tags": ["a", "b"]},
            [],
            id="option_keys_lowercased",
        ),
        pytest.param(
            [":status: open", ":Status: closed"],
            {"status": "open"},
            [
                (
                    4,
                    "multi-line need option 'Status' repeats 'status': the first "
                    "value is kept",
                )
            ],
            id="option_key_repeated_in_another_case",
        ),
        pytest.param(
            [":Type: spec", ":Content: x"],
            {"type": "req", "content": "Body {{ 1 + 1 }} here."},
            [
                (
                    3,
                    "multi-line need option 'Type' repeats the block's own 'type': ignored",
                ),
                (
                    4,
                    "multi-line need option 'Content' repeats the block's own "
                    "'content': ignored",
                ),
            ],
            id="option_naming_a_record_key_in_another_case",
        ),
        pytest.param(
            [":delete: true"],
            {"title": "Q3 block"},
            [
                (
                    3,
                    "multi-line need option 'delete' is not an option a multi-line "
                    "need takes: ignored",
                )
            ],
            id="directive_only_option_warned",
        ),
    ],
)
def test_options_are_the_need_directives(
    tmp_path: Path,
    make_app: _MakeApp,
    options: list[str],
    expected: dict[str, Any] | None,
    warnings: list[tuple[int, str]],
) -> None:
    """A block takes the options ``.. req::`` takes, converted as the directive converts
    them: links and tags split, typed fields coerced, ``jinja_content`` a flag. A key
    the directive does not know is ignored with a warning at its line, the need kept; a
    value Sphinx-Needs refuses refuses the need, warned at the open line."""
    source = Q3_HEAD + "// :id: REQ_Q3\n"
    source += "".join(f"// {option}\n" for option in options) + Q3_BODY
    _blocks(
        tmp_path,
        {
            "docs/page_q.rst": "Q\n=\n\n.. src-trace::\n   :project: src\n   :file: q.c\n",
            "src/q.c": source,
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == [
        _multiline(f"src/q.c:{line}", message) for line, message in warnings
    ]
    need = _need(app, "REQ_Q3")
    if expected is None:
        assert need is None
        return
    assert need is not None
    fields = {key: value for key, value in expected.items() if key != CARD}
    assert {key: need[key] for key in fields} == fields
    if CARD in expected:
        card = _card(app, "page_q.html", "REQ_Q3")
        if expected[CARD] is None:
            assert card is None
        else:
            assert card is not None
            assert expected[CARD] in card


def test_an_empty_id_is_refused_with_the_directives_message(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    _blocks(
        tmp_path,
        {
            "docs/page_q.rst": "Q\n=\n\n.. src-trace::\n   :project: src\n   :file: q.c\n",
            "src/q.c": Q3_HEAD + "// :id:\n" + Q3_BODY,
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == [
        _multiline(
            "src/q.c:2",
            "invalid_option: multi-line need could not be created: Invalid value for "
            "'id' option: 'id' must not be empty",
        )
    ]
    assert not [
        need for need in _json(app)["needs"].values() if need["docname"] == "page_q"
    ]


def test_an_unknown_type_is_refused_at_the_open_line(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    _blocks(
        tmp_path,
        {
            "docs/page_q.rst": "Q\n=\n\n.. src-trace::\n   :project: src\n   :file: q.c\n",
            "src/q.c": "// a block of an unknown type\n// @need nosuchtype: T\n"
            "// :id: X_1\n// @endneed\n",
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == [
        _multiline(
            "src/q.c:2",
            "invalid_type: multi-line need could not be created: Unknown need type "
            "'nosuchtype'.",
        )
    ]
    assert _need(app, "X_1") is None


DUPLICATES = """\
/**
 * @need req: Block first
 * :id: DUP_1
 * @endneed
 */
void a() {}
// @one-line after the block, DUP_1, impl
void b() {}
// @one-line before the block, DUP_2, impl
void c() {}
// @need req: Block after the one-line need
// :id: DUP_2
// @endneed
void d() {}
// @need req: The first of two blocks
// :id: DUP_3
// @endneed
void e() {}
// @need req: The second of two blocks
// :id: DUP_3
// @endneed
void f() {}
// @need req: Generated id block
// @endneed
void g() {}
"""


def _duplicate(location: str, kind: str, need_id: str) -> str:
    return _warning(
        location,
        f"{kind} {need_id!r} is already defined in document 'page_d': not created again "
        "by the src-trace directive in 'page_d' (give the markers distinct ids)",
        "duplicate_need",
    )


def test_one_need_per_id_across_kinds_the_earlier_line_wins(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """One-line needs and blocks are one list in source order: of two markers with one
    id, whatever their kinds, the earlier keeps it and the warning names the kind of the
    one skipped. A block without ``:id:`` gets the id Sphinx-Needs generates."""
    _blocks(
        tmp_path,
        {
            "docs/page_d.rst": "D\n=\n\n.. src-trace::\n   :project: src\n   :file: d.c\n",
            "src/d.c": DUPLICATES,
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == [
        _duplicate("src/d.c:7", "one-line need", "DUP_1"),
        _duplicate("src/d.c:11", "multi-line need", "DUP_2"),
        _duplicate("src/d.c:19", "multi-line need", "DUP_3"),
    ]
    needs = _json(app)["needs"]
    assert (needs["DUP_1"]["type"], needs["DUP_1"]["title"]) == ("req", "Block first")
    assert (needs["DUP_2"]["type"], needs["DUP_2"]["title"]) == (
        "impl",
        "one-line before the block",
    )
    assert needs["DUP_3"]["title"] == "The first of two blocks"
    generated = "R_" + hashlib.sha1(b"Generated id block").hexdigest().upper()[:5]
    assert needs[generated]["title"] == "Generated id block"


ORDER = {
    "src/order/a.c": (
        "// @one-line A1, IMPL_A1_ONE, impl\n"
        "void a1() {}\n"
        "// @need req: Block B1\n"
        "// :id: REQ_B1_BLK\n"
        "// @endneed\n"
        "void b1() {}\n\n\n\n\n"
        "// @one-line A2, IMPL_A2_ONE, impl\n"
        "void a2() {}\n"
    ),
    "src/order/b.c": (
        "void nothing() {}\n"
        "// @one-line C1, IMPL_C1_ONE, impl\n"
        "void c1() {}\n"
        "// @need req: Block D1\n"
        "// :id: REQ_D1_BLK\n"
        "// @endneed\n"
        "void d1() {}\n"
    ),
}


def _card_order(app: SphinxTestApp, page: str) -> list[str]:
    html = Path(app.outdir, page).read_text(encoding="utf-8")
    return list(
        dict.fromkeys(re.findall(r'<table class="need[^"]*" id="([A-Z0-9_]+)"', html))
    )


def test_cards_follow_the_open_lines_across_files(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block takes its place by its open line, in the order one-line needs already
    have: by row across the directive's files, then by file."""
    _blocks(
        tmp_path,
        {
            **ORDER,
            "docs/page_o.rst": "O\n=\n\n.. src-trace::\n   :project: src\n"
            "   :directory: order\n",
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == []
    assert _card_order(app, "page_o.html") == [
        "IMPL_A1_ONE",
        "IMPL_C1_ONE",
        "REQ_B1_BLK",
        "REQ_D1_BLK",
        "IMPL_A2_ONE",
    ]


@pytest.mark.skipif(
    not parallel_available, reason="Sphinx reads sources in parallel on POSIX only"
)
def test_parallel_build_matches_the_serial_one(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """``-j 2`` records the same needs, warnings and content as a serial build: a block
    is created through ``add_need``, which the parallel merge already handles."""
    _blocks(tmp_path, FOUR_CELLS)
    serial = _build(tmp_path, make_app)
    serial_needs = _json(serial)["needs"]
    serial_warnings = sorted(build_warnings(serial))
    serial_html = {
        need_id: _content_html(serial, f"{page}.html", need_id)
        for need_id, (_, page, _, _) in CELLS.items()
    }

    parallel = _build(tmp_path, make_app, parallel=2)

    assert _json(parallel)["needs"] == serial_needs
    assert sorted(_warnings(parallel)) == serial_warnings
    assert {
        need_id: _content_html(parallel, f"{page}.html", need_id)
        for need_id, (_, page, _, _) in CELLS.items()
    } == serial_html


INCREMENTAL = (
    "// @need req: Other title\n//\n// Other body.\n// @endneed\nvoid o() {}\n"
)


def test_an_edited_block_is_read_again(tmp_path: Path, make_app: _MakeApp) -> None:
    """An incremental build after editing a block's body updates its content; after
    editing its title the generated id moves, with no duplicate warning."""
    _blocks(
        tmp_path,
        {
            "docs/page_i.rst": "I\n=\n\n.. src-trace::\n   :project: src\n   :file: i.c\n",
            "src/i.c": INCREMENTAL,
        },
    )
    first_id = "R_" + hashlib.sha1(b"Other title").hexdigest().upper()[:5]
    app = _build(tmp_path, make_app)
    assert _need(app, first_id)["content"] == "Other body."  # type: ignore[index]

    source = tmp_path / "src" / "i.c"
    source.write_text(
        INCREMENTAL.replace("Other body.", "Edited body."), encoding="utf-8"
    )
    _touch_later(source)
    app = _build(tmp_path, make_app, freshenv=False)
    assert _warnings(app) == []
    assert _need(app, first_id)["content"] == "Edited body."  # type: ignore[index]

    source.write_text(
        INCREMENTAL.replace("Other body.", "Edited body.").replace(
            "Other title", "Edited title"
        ),
        encoding="utf-8",
    )
    _touch_later(source)
    app = _build(tmp_path, make_app, freshenv=False)
    second_id = "R_" + hashlib.sha1(b"Edited title").hexdigest().upper()[:5]
    assert _warnings(app) == []
    assert _need(app, first_id) is None
    assert _need(app, second_id)["content"] == "Edited body."  # type: ignore[index]


def test_analyser_warnings_on_blocks_are_multiline_need(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A malformed block is reported at its source line under ``codelinks.multiline_need``
    -- every warning about blocks in the build shares one subtype -- while a malformed
    one-line marker stays ``codelinks.oneline``."""
    _blocks(
        tmp_path,
        {
            "docs/page_w.rst": "W\n=\n\n.. src-trace::\n   :project: src\n   :file: w.c\n",
            "src/w.c": "// @need req: Never closed\n// :id: REQ_OPEN\nvoid w() {}\n"
            "// @only a title, X_1, impl, [A], extra\nvoid x() {}\n",
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == [
        _multiline(
            "src/w.c:1",
            "multiline_need_unterminated: no '@endneed' line before the comment ends; "
            "the block is skipped",
        ),
        _warning(
            "src/w.c:4",
            "too_many_fields: 5 given fields, maximum is 4",
            "oneline",
        ),
    ]


TXT_MARKUP = """
[codelinks.projects.src.analyse.multiline_needs]
markups = { rst = ".rst", md = ".md", txt = ".txt" }
"""

PAGE_K = """\
K
=

.. src-trace::
   :project: src
   :file: k.c

.. src-trace::
   :project: src
   :file: k2.c

.. src-trace::
   :project: src
   :file: k3.c
"""


def _txt_block(need_id: str, *, hide: bool = False, body: str | None = None) -> str:
    """A ``@need[txt]`` block: ``.txt`` is a suffix no parser of the project claims."""
    lines = [f"// @need[txt] req: {need_id} title", f"// :id: {need_id}"]
    if hide:
        lines.append("// :hide:")
    if body is not None:
        lines += ["//", f"// {body}"]
    return "\n".join([*lines, "// @endneed", f"void {need_id.lower()}() {{}}", ""])


UNCLAIMED = {
    "docs/page_k.rst": PAGE_K,
    # two blocks with a body and a hidden one: one warning for the directive
    "src/k.c": _txt_block("TXT_1", body="Plain *one* text.")
    + _txt_block("TXT_2", body="Plain *two* text.")
    + _txt_block("TXT_HIDDEN", hide=True, body="Hidden *text*."),
    # a hidden block and one without a body: nothing is parsed, nothing warned
    "src/k2.c": _txt_block("TXT_HIDDEN_2", hide=True, body="Hidden *text*.")
    + _txt_block("TXT_BLANK"),
    # another directive: warned again
    "src/k3.c": _txt_block("TXT_3", body="Plain *three* text."),
}


def test_an_unclaimed_markup_is_parsed_as_the_page(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A markup whose suffix no parser claims is parsed as the page's markup: every
    need kept, its ``doctype`` as declared, and one warning per directive and markup at
    the directive -- none where every such block is hidden or has no body."""
    _blocks(tmp_path, UNCLAIMED, toml_extra=TXT_MARKUP)
    app = _build(tmp_path, make_app)

    unclaimed = (
        "Multi-line needs declare doctype '.txt', which this project cannot parse "
        "content in: '.txt' is not a registered source suffix (registered: '.md', "
        "'.rst'). Their content was parsed as this page's markup instead. Add the suffix "
        "to source_suffix with a reStructuredText or MyST parser, or map the markup to a "
        "suffix it parses."
    )
    assert build_warnings(app) == [
        _multiline("<srcdir>/page_k.rst:4", unclaimed),
        _multiline("<srcdir>/page_k.rst:12", unclaimed),
    ]
    needs = _json(app)["needs"]
    for need_id in (
        "TXT_1",
        "TXT_2",
        "TXT_HIDDEN",
        "TXT_HIDDEN_2",
        "TXT_BLANK",
        "TXT_3",
    ):
        assert needs[need_id]["doctype"] == ".txt", need_id
    for need_id, word in (("TXT_1", "one"), ("TXT_2", "two"), ("TXT_3", "three")):
        assert f"<em>{word}</em>" in _content_html(app, "page_k.html", need_id)
    assert _card(app, "page_k.html", "TXT_HIDDEN") is None


def test_a_hidden_block_with_a_declared_full_title_is_not_warned_unclaimed(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A hidden block without ``:id:`` whose ``:full_title:`` the project declares, in a
    markup no parser claims: nothing of it is parsed, so nothing is warned -- the
    lookup that finds it hidden uses the id it is given (#2410)."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": CONF.replace(
                "needs_fields = {", 'needs_fields = {"full_title": {"nullable": True}, '
            ),
            "docs/page_h.rst": "H\n=\n\n.. src-trace::\n   :project: src\n   :file: h.c\n",
            "src/h.c": "// @need[txt] req: Short title\n"
            "// :full_title: A much longer title\n// :hide:\n//\n// Hidden *text*.\n"
            "// @endneed\nvoid h() {}\n",
        },
        toml_extra=TXT_MARKUP,
    )
    app = _build(tmp_path, make_app)
    assert _warnings(app) == []
    assert _need(app, SHORT_TITLE_ID) is not None
    assert _card(app, "page_h.html", SHORT_TITLE_ID) is None


TEMPLATE = "**TPL bold** and `tlink <https://t.example>`_ then: {{content}}\n"
TEMPLATED_BLOCK = """\
// @need[md] req: Templated block
// :id: REQ_TPL
// {option}
//
// Body [blink](https://b.example).
// @endneed
void templated() {{}}
"""


@pytest.mark.parametrize(
    ("option", "conf"),
    [
        pytest.param(":template: rsttpl", "", id="the_blocks_template"),
        pytest.param(
            ":status: open",
            'needs_fields = {"template": {"default": "rsttpl"}}\n',
            id="the_projects_default",
        ),
        pytest.param(
            ":status: open",
            'needs_fields = {"template": {"predicates": '
            '[(\'id == "REQ_TPL"\', "rsttpl")]}}\n',
            id="a_project_predicate",
        ),
    ],
)
def test_a_templated_block_is_parsed_as_the_page(
    tmp_path: Path, make_app: _MakeApp, option: str, conf: str
) -> None:
    """A template is a file of the project, written in the page's markup: a block
    rendered through one -- its own ``:template:``, or one the project gives -- is
    parsed as the page's markup, template and body together, as ``needimport`` does."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": CONF.replace("needs_fields = ", "_unused = ") + conf,
            "docs/needs_templates/rsttpl.need": TEMPLATE,
            "docs/page_t.rst": "T\n=\n\n.. src-trace::\n   :project: src\n   :file: t.c\n",
            "src/t.c": TEMPLATED_BLOCK.format(option=option),
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == []
    html = _content_html(app, "page_t.html", "REQ_TPL")
    # the template's reStructuredText renders ...
    assert "<strong>TPL bold</strong>" in html
    assert '<a class="reference external" href="https://t.example">tlink</a>' in html
    # ... and so the body is reStructuredText too: its Markdown link is text
    assert "[blink](" in html
    assert _need(app, "REQ_TPL")["doctype"] == ".md"  # type: ignore[index]


def test_an_upper_case_id_is_the_id(tmp_path: Path, make_app: _MakeApp) -> None:
    """docutils lowercases a directive's option names, so ``:ID:`` is the id."""
    _blocks(
        tmp_path,
        {
            "docs/page_q.rst": "Q\n=\n\n.. src-trace::\n   :project: src\n   :file: q.c\n",
            "src/q.c": Q3_HEAD + "// :ID: REQ_UPPER\n" + Q3_BODY,
        },
    )
    app = _build(tmp_path, make_app)

    assert build_warnings(app) == []
    assert _need(app, "REQ_UPPER") is not None


def test_a_fallback_body_still_names_the_source_line(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A body in a markup no parser claims is parsed in the page's markup, still
    anchored at its source line: a bad role in it names the source file and line."""
    _blocks(
        tmp_path,
        {
            "docs/page_f.rst": "F\n=\n\n.. src-trace::\n   :project: src\n   :file: fb.c\n",
            "src/fb.c": "// @need[txt] req: Fallback body\n// :id: REQ_FB\n//\n"
            "// A bad role :nosuchrole:`x` here.\n// @endneed\nvoid fb() {}\n",
        },
        toml_extra=TXT_MARKUP,
    )
    app = _build(tmp_path, make_app)

    docutils = " [docutils]" if _SHOWS_WARNING_TYPES else ""
    assert build_warnings(app, srcdir=tmp_path) == [
        f"<srcdir>/{_at('src', 'fb.c')}:4: ERROR: Unknown interpreted text role "
        f'"nosuchrole".{docutils}',
        _multiline(
            f"<srcdir>/{_at('docs', 'page_f.rst')}:4",
            "Multi-line needs declare doctype '.txt', which this project cannot parse "
            "content in: '.txt' is not a registered source suffix (registered: '.md', "
            "'.rst'). Their content was parsed as this page's markup instead. Add the "
            "suffix to source_suffix with a reStructuredText or MyST parser, or map the "
            "markup to a suffix it parses.",
        ),
    ]
    assert _need(app, "REQ_FB")["doctype"] == ".txt"  # type: ignore[index]


def test_full_title_does_not_move_the_predicted_id(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block without ``:id:`` but with ``:full_title:`` (not an option it takes, so
    ignored): the id predicted for the duplicate check and the ``[docs]`` link is the
    one the need gets, from the title alone."""
    _blocks(
        tmp_path,
        {
            "docs/page_f.rst": "F\n=\n\n.. src-trace::\n   :project: src\n   :file: f.c\n",
            "src/f.c": "// @need req: Short title\n// :full_title: A much longer title\n"
            "// @endneed\nvoid f() {}\n",
        },
    )
    app = _build(tmp_path, make_app)
    need_id = "R_" + hashlib.sha1(b"Short title").hexdigest().upper()[:5]
    assert need_id in _json(app)["needs"]
    page = Path(app.outdir, "src", "f.html").read_text(encoding="utf-8")
    assert f'href="../page_f.html#{need_id}">[docs]</a>' in page


#: the id of a block titled ``Short title``, hashed from its title
SHORT_TITLE_ID = "R_" + hashlib.sha1(b"Short title").hexdigest().upper()[:5]
#: the id hashed from its ``full_title``, which a block's need is never given (#2410)
FULL_TITLE_ID = "R_" + hashlib.sha1(b"A much longer title").hexdigest().upper()[:5]


def _declared_full_title(
    tmp_path: Path, make_app: _MakeApp, owner: str | None = None
) -> SphinxTestApp:
    """Build a block without ``:id:`` whose ``:full_title:`` the project declares as a
    field, on ``page_f``; with ``owner``, a need of that id is written in ``owner.rst``,
    read before ``page_f``."""
    files = {
        "docs/conf.py": CONF.replace(
            "needs_fields = {", 'needs_fields = {"full_title": {"nullable": True}, '
        ),
        "docs/page_f.rst": "F\n=\n\n.. src-trace::\n   :project: src\n   :file: f.c\n",
        "src/f.c": "// @need req: Short title\n// :full_title: A much longer title\n"
        "// @endneed\nvoid f() {}\n",
    }
    if owner is not None:
        files["docs/owner.rst"] = (
            f"Owner\n=====\n\n.. req:: Written by hand\n   :id: {owner}\n"
        )
    _blocks(tmp_path, files)
    return _build(tmp_path, make_app)


def test_a_declared_full_title_is_the_field_and_the_id_is_the_title_s(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block without ``:id:`` whose ``:full_title:`` the project declares: the field
    holds it, the need's id is hashed from the title (the record path passes no full
    title), and the id the duplicate check and the ``[docs]`` link use -- the one
    :func:`would_be_id` predicts -- is that same id (#2410)."""
    app = _declared_full_title(tmp_path, make_app)
    needs = _json(app)["needs"]
    on_page = [
        need_id for need_id, need in needs.items() if need["docname"] == "page_f"
    ]
    assert on_page == [SHORT_TITLE_ID]
    assert needs[SHORT_TITLE_ID]["full_title"] == "A much longer title"
    page = Path(app.outdir, "src", "f.html").read_text(encoding="utf-8")
    assert re.findall(r'href="([^"]*)">\[docs\]</a>', page) == [
        f"../page_f.html#{SHORT_TITLE_ID}"
    ]


def test_a_declared_full_title_s_duplicate_check_names_the_need_s_id(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """The duplicate check looks up the id the block's need would get: a need that owns
    it already is found, and the block is skipped with the duplicate warning, naming
    that id, rather than refused by Sphinx-Needs (#2410)."""
    app = _declared_full_title(tmp_path, make_app, owner=SHORT_TITLE_ID)
    assert _warnings(app) == [
        _warning(
            "src/f.c:1",
            f"multi-line need {SHORT_TITLE_ID!r} is already defined in document "
            "'owner': not created again by the src-trace directive in 'page_f' "
            "(narrow one directive's scope)",
            "duplicate_need",
        )
    ]
    assert _need(app, SHORT_TITLE_ID)["title"] == "Written by hand"  # type: ignore[index]


def test_a_declared_full_title_s_skip_is_read_again_when_its_owner_goes(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """The skip is remembered as any duplicate's is: when the need that owned the id
    goes, the next incremental build reads ``page_f`` again and the block's need is
    created (#2410)."""
    _declared_full_title(tmp_path, make_app, owner=SHORT_TITLE_ID)
    owner = tmp_path / "docs" / "owner.rst"
    owner.write_text("Owner\n=====\n\nNo need.\n", encoding="utf-8")
    _touch_later(owner)
    app = _build(tmp_path, make_app, freshenv=False)
    assert _warnings(app) == []
    assert _need(app, SHORT_TITLE_ID)["docname"] == "page_f"  # type: ignore[index]


def test_a_need_of_the_full_title_s_id_does_not_skip_the_block(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A need whose id is the one hashed from the block's ``:full_title:`` is no
    duplicate: the block's need is not given that id, so it is created (#2410)."""
    app = _declared_full_title(tmp_path, make_app, owner=FULL_TITLE_ID)
    assert _warnings(app) == []
    needs = _json(app)["needs"]
    assert needs[FULL_TITLE_ID]["title"] == "Written by hand"
    assert needs[SHORT_TITLE_ID]["title"] == "Short title"


def test_a_link_type_named_full_title_is_kept_on_a_block(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block without ``:id:`` that sets a LINK type named ``full_title``: the need
    keeps the link -- the record path dropped it as the legacy ``full_title`` key
    (#2466) -- and its id is hashed from the title, the one the ``[docs]`` link names."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": CONF + 'needs_links = {"full_title": {}}\n',
            "docs/page_f.rst": "F\n=\n\n.. src-trace::\n   :project: src\n   :file: f.c\n",
            "src/f.c": "// @need req: Short title\n// :full_title: REQ_HOST\n"
            "// @endneed\nvoid f() {}\n",
        },
    )
    app = _build(tmp_path, make_app)
    assert _warnings(app) == []
    assert _need(app, SHORT_TITLE_ID)["full_title"] == ["REQ_HOST"]  # type: ignore[index]
    page = Path(app.outdir, "src", "f.html").read_text(encoding="utf-8")
    assert re.findall(r'href="([^"]*)">\[docs\]</a>', page) == [
        f"../page_f.html#{SHORT_TITLE_ID}"
    ]


#: a project declaring a field named ``description``
DESCRIPTION_CONF = CONF.replace(
    "needs_fields = {", 'needs_fields = {"description": {"nullable": True}, '
)
#: the id of a block with an empty title and no body: hashed from the empty content
EMPTY_TITLE_ID = "R_" + hashlib.sha1(b"").hexdigest().upper()[:5]


def test_a_declared_description_is_kept_on_a_body_less_block(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block with no body whose ``:description:`` the project declares: the field
    holds it and the content stays empty -- the legacy rename (sphinx-needs before 4.0
    wrote the content as ``description``) is for a record with no ``content``, and a
    block's record always has one (#2465)."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": DESCRIPTION_CONF,
            "docs/page_d.rst": "D\n=\n\n.. src-trace::\n   :project: src\n   :file: d.c\n",
            "src/d.c": "// @need req: Block need\n// :id: REQ_BLK\n"
            "// :description: block text\n// @endneed\nvoid f() {}\n",
        },
    )
    app = _build(tmp_path, make_app)
    assert _warnings(app) == []
    need = _need(app, "REQ_BLK")
    assert need is not None
    assert (need["description"], need["content"]) == ("block text", "")


def test_a_declared_description_does_not_move_the_predicted_id(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A block without ``:id:``, with an empty title and no body, whose
    ``:description:`` the project declares: its id is hashed from the empty content,
    the one :func:`would_be_id` predicts for the duplicate check and the ``[docs]`` link
    -- not from the field's text taken as the content (#2465)."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": DESCRIPTION_CONF,
            "docs/page_d.rst": "D\n=\n\n.. src-trace::\n   :project: src\n   :file: d.c\n",
            "src/d.c": "// @need req:\n// :description: hashed from me\n"
            "// @endneed\nvoid f() {}\n",
        },
    )
    app = _build(tmp_path, make_app)
    needs = _json(app)["needs"]
    on_page = [
        need_id for need_id, need in needs.items() if need["docname"] == "page_d"
    ]
    assert on_page == [EMPTY_TITLE_ID]
    assert needs[EMPTY_TITLE_ID]["description"] == "hashed from me"
    page = Path(app.outdir, "src", "d.html").read_text(encoding="utf-8")
    assert re.findall(r'href="([^"]*)">\[docs\]</a>', page) == [
        f"../page_d.html#{EMPTY_TITLE_ID}"
    ]


def test_a_link_type_named_description_is_kept_on_a_block(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """A body-less block that sets a LINK type named ``description``: the need keeps
    the link, where the legacy rename made its text the content and lost it (#2465)."""
    _blocks(
        tmp_path,
        {
            "docs/conf.py": CONF + 'needs_links = {"description": {}}\n',
            "docs/page_d.rst": "D\n=\n\n.. src-trace::\n   :project: src\n   :file: d.c\n",
            "src/d.c": "// @need req: Block need\n// :id: REQ_BLK\n"
            "// :description: REQ_HOST\n// @endneed\nvoid f() {}\n",
        },
    )
    app = _build(tmp_path, make_app)
    assert _warnings(app) == []
    need = _need(app, "REQ_BLK")
    assert need is not None
    assert (need["description"], need["content"]) == (["REQ_HOST"], "")


def test_one_line_needs_keep_the_analysis_order(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """Two files whose string order and path order differ (``a-c.c`` before ``a/b.c``
    as strings, after as paths), a one-line need on the same row in each: the cards
    keep the order the analysis gives, the one before multi-line needs."""
    _blocks(
        tmp_path,
        {
            "src/o2/a/b.c": "// @one-line in b, IMPL_AB_ONE, impl\n",
            "src/o2/a-c.c": "// @one-line in ac, IMPL_AC_ONE, impl\n",
            "docs/page_o2.rst": "O\n=\n\n.. src-trace::\n   :project: src\n"
            "   :directory: o2\n",
        },
    )
    app = _build(tmp_path, make_app)
    assert _card_order(app, "page_o2.html") == ["IMPL_AC_ONE", "IMPL_AB_ONE"]


XPARSER = """\
from docutils.parsers.rst import Parser as _Rst
from sphinx.parsers import Parser as _SphinxParser


class XParser(_SphinxParser):
    supported = ("xrst",)

    def parse(self, inputstring, document):
        _Rst().parse(inputstring, document)


def setup(app):
    app.add_source_suffix(".xrst", "xrst")
    app.add_source_parser(XParser)
"""


def test_a_fallback_on_a_page_of_a_third_parser_keeps_the_need(
    tmp_path: Path, make_app: _MakeApp
) -> None:
    """On a page whose own parser is neither reStructuredText nor MyST, the page's
    suffix is unclaimed too: the body is parsed by the page's parser, unanchored (its
    warnings at the page), and the need is kept."""
    _blocks(
        tmp_path,
        {
            "docs/xparser_ext.py": XPARSER,
            "docs/conf.py": CONF
            + "import os, sys\nsys.path.insert(0, os.path.dirname(__file__))\n"
            "extensions.append('xparser_ext')\n"
            'source_suffix = {".rst": "restructuredtext", ".md": "markdown", '
            '".xrst": "xrst"}\n',
            "docs/page_x.xrst": "X\n=\n\n.. src-trace::\n   :project: src\n   :file: fbx.c\n",
            "src/fbx.c": "// @need[txt] req: Third parser\n// :id: REQ_FBX\n//\n"
            "// A bad role :nosuchrole:`x` and *em*.\n// @endneed\nvoid f() {}\n",
        },
        toml_extra=TXT_MARKUP,
    )
    app = _build(tmp_path, make_app)

    docutils = " [docutils]" if _SHOWS_WARNING_TYPES else ""
    assert build_warnings(app) == [
        f'<srcdir>/page_x.xrst:4: ERROR: Unknown interpreted text role "nosuchrole".'
        f"{docutils}",
        _multiline(
            "<srcdir>/page_x.xrst:4",
            "Multi-line needs declare doctype '.txt', which this project cannot parse "
            "content in: '.txt' is not a registered source suffix (registered: '.md', "
            "'.rst', '.xrst'). Their content was parsed as this page's markup instead. "
            "Add the suffix to source_suffix with a reStructuredText or MyST parser, or "
            "map the markup to a suffix it parses.",
        ),
    ]
    assert _need(app, "REQ_FBX")["doctype"] == ".txt"  # type: ignore[index]
    assert "<em>em</em>" in _content_html(app, "page_x.html", "REQ_FBX")


def test_a_fallback_on_a_myst_page_is_myst(tmp_path: Path, make_app: _MakeApp) -> None:
    """On a MyST page an unclaimed markup falls back to MyST, the page's markup, still
    anchored at the body's source line: its Markdown link renders, and an unresolved
    ``{ref}`` names the source file and line."""
    _blocks(
        tmp_path,
        {
            "docs/page_m.md": "# M\n\n```{src-trace}\n:project: src\n:file: fbm.c\n```\n",
            "src/fbm.c": "// @need[txt] req: MyST fallback\n// :id: REQ_FBM\n//\n"
            "// A [link](https://x.example) and {ref}`nolabel_md`.\n// @endneed\n"
            "void f() {}\n",
        },
        toml_extra=TXT_MARKUP,
    )
    app = _build(tmp_path, make_app)

    ref = " [ref.ref]" if _SHOWS_WARNING_TYPES else ""
    assert sorted(build_warnings(app, srcdir=tmp_path)) == sorted(
        [
            f"<srcdir>/{_at('src', 'fbm.c')}:4: WARNING: undefined label: "
            f"'nolabel_md'{ref}",
            _multiline(
                f"<srcdir>/{_at('docs', 'page_m.md')}:3",
                "Multi-line needs declare doctype '.txt', which this project cannot "
                "parse content in: '.txt' is not a registered source suffix "
                "(registered: '.md', '.rst'). Their content was parsed as this page's "
                "markup instead. Add the suffix to source_suffix with a "
                "reStructuredText or MyST parser, or map the markup to a suffix it "
                "parses.",
            ),
        ]
    )
    assert _need(app, "REQ_FBM")["doctype"] == ".txt"  # type: ignore[index]
    assert '<a class="reference external" href="https://x.example">link</a>' in (
        _content_html(app, "page_m.html", "REQ_FBM")
    )