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bee9bbb | 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 | """Site-specific semantic checks for interactive clone markup and its inventory."""
from __future__ import annotations
from dataclasses import dataclass
from html.parser import HTMLParser
import json
from pathlib import Path
from typing import Mapping
from urllib.parse import urlsplit
_BEHAVIORS = {
"navigate",
"submit",
"client-state",
"durable-state",
"safe-boundary",
}
_TRACE_IDS = {f"trace-{number:03d}" for number in range(1, 24)}
_VOID_TAGS = {
"area",
"base",
"br",
"col",
"embed",
"hr",
"img",
"input",
"link",
"meta",
"param",
"source",
"track",
"wbr",
}
_CONTROL_TAGS = {"button", "input", "select", "textarea"}
_BOOLEAN_CLIENT_ACTION_ATTRIBUTES = {"data-login-open"}
@dataclass(frozen=True)
class InteractionFinding:
route: str
code: str
label: str
@dataclass(frozen=True)
class ControlContract:
id: str
route: str
selector: str
behavior: str
target: str
persistence: str
trace_ids: tuple[str, ...]
evidence_refs: tuple[str, ...]
@dataclass
class _Element:
tag: str
attrs: Mapping[str, str]
text: list[str]
class _InteractionParser(HTMLParser):
def __init__(self, route: str) -> None:
super().__init__(convert_charrefs=True)
self.route = route
self.findings: list[InteractionFinding] = []
self._pending_findings: list[tuple[str, _Element]] = []
self._open: list[_Element] = []
self._anchors: list[_Element] = []
self._elements_by_id: dict[str, _Element] = {}
self._disabled_controls: list[_Element] = []
def handle_starttag(self, tag: str, attrs: list[tuple[str, str | None]]) -> None:
normalized_tag = tag.lower()
attributes = {
name.lower(): "" if value is None else value for name, value in attrs
}
element = _Element(normalized_tag, attributes, [])
element_id = attributes.get("id", "").strip()
if element_id:
self._elements_by_id[element_id] = element
if normalized_tag == "a":
self._anchors.append(element)
href = attributes.get("href", "").strip()
if not href or href == "#" or href.lower().startswith("javascript:"):
self._pending_findings.append(("placeholder-link", element))
elif normalized_tag == "button":
self._audit_button(element)
elif normalized_tag == "input" and attributes.get("type", "").lower() == "submit":
self._audit_submit(element)
if normalized_tag in _CONTROL_TAGS and "disabled" in attributes:
self._disabled_controls.append(element)
if normalized_tag == "img" and attributes.get("alt", "").strip():
for ancestor in self._open:
ancestor.text.append(attributes["alt"])
if normalized_tag == "area" or (
normalized_tag == "img" and attributes.get("usemap", "").strip()
):
self._finding("image-map-control", self._label(element, normalized_tag))
if normalized_tag not in _VOID_TAGS:
self._open.append(element)
def handle_startendtag(
self, tag: str, attrs: list[tuple[str, str | None]]
) -> None:
self.handle_starttag(tag, attrs)
if tag.lower() not in _VOID_TAGS:
self.handle_endtag(tag)
def handle_endtag(self, tag: str) -> None:
normalized_tag = tag.lower()
for index in range(len(self._open) - 1, -1, -1):
if self._open[index].tag == normalized_tag:
del self._open[index:]
return
def handle_data(self, data: str) -> None:
for element in self._open:
element.text.append(data)
def close(self) -> None:
super().close()
for code, element in self._pending_findings:
self._finding(code, self._label(element, "control"))
for anchor in self._anchors:
if _is_local_target(anchor.attrs.get("href", "").strip()) and not self._accessible_name(
anchor
):
self._finding("unlabeled-link", "link")
for control in self._disabled_controls:
description_ids = control.attrs.get("aria-describedby", "").split()
if not description_ids or not all(
self._describes_control(description_id)
for description_id in description_ids
):
self._finding(
"unexplained-disabled-control", self._label(control, "control")
)
def _audit_button(self, element: _Element) -> None:
if "disabled" in element.attrs:
return
button_type = element.attrs.get("type", "submit").strip().lower()
if button_type == "button" and not self._has_client_action(element):
self._pending_findings.append(("inert-button", element))
elif button_type == "submit":
self._audit_submit(element)
def _audit_submit(self, element: _Element) -> None:
if "disabled" in element.attrs:
return
form = next(
(item for item in reversed(self._open) if item.tag == "form"), None
)
if form is None or not _is_local_target(form.attrs.get("action", "")):
self._pending_findings.append(
("orphan-submit" if form is None else "nonlocal-submit", element)
)
def _describes_control(self, description_id: str) -> bool:
description = self._elements_by_id.get(description_id)
return description is not None and bool("".join(description.text).strip())
@staticmethod
def _has_client_action(element: _Element) -> bool:
return bool(element.attrs.get("data-control-action", "").strip()) or any(
attribute in element.attrs
for attribute in _BOOLEAN_CLIENT_ACTION_ATTRIBUTES
)
def _finding(self, code: str, label: str) -> None:
self.findings.append(InteractionFinding(self.route, code, label))
def _label(self, element: _Element, fallback: str) -> str:
return self._accessible_name(element) or fallback
def _accessible_name(self, element: _Element) -> str:
labelled_by = element.attrs.get("aria-labelledby", "").split()
referenced = " ".join(
"".join(self._elements_by_id[item_id].text).strip()
for item_id in labelled_by
if item_id in self._elements_by_id
)
return (
element.attrs.get("aria-label", "").strip()
or element.attrs.get("title", "").strip()
or element.attrs.get("alt", "").strip()
or referenced
or "".join(element.text).strip()
)
def audit_markup(html: str, *, route: str) -> tuple[InteractionFinding, ...]:
parser = _InteractionParser(route)
parser.feed(html)
parser.close()
return tuple(parser.findings)
def load_control_contract(path: Path) -> tuple[ControlContract, ...]:
payload = json.loads(path.read_text(encoding="utf-8"))
entries = payload.get("controls") if isinstance(payload, dict) else None
if not isinstance(entries, list):
raise ValueError("control contract must provide a controls list")
controls: list[ControlContract] = []
seen_ids: set[str] = set()
for entry in entries:
if not isinstance(entry, dict):
raise ValueError("control contract entries must be objects")
control = _control_from_entry(entry)
if control.id in seen_ids:
raise ValueError(f"duplicate control id: {control.id}")
seen_ids.add(control.id)
controls.append(control)
return tuple(controls)
def _control_from_entry(entry: Mapping[str, object]) -> ControlContract:
required_strings = (
"id",
"route",
"selector",
"behavior",
"target",
"persistence",
)
values: dict[str, str] = {}
for field in required_strings:
value = entry.get(field)
if not isinstance(value, str) or not value.strip():
raise ValueError(f"control {field} must be a non-empty string")
values[field] = value
if values["behavior"] not in _BEHAVIORS:
raise ValueError(f"unknown control behavior: {values['behavior']}")
if not _is_local_target(values["route"]) or not _is_local_target(
values["target"]
):
raise ValueError("control routes and targets must be local paths")
trace_ids = _string_list(entry.get("trace_ids"), "trace_ids")
unknown_trace_ids = set(trace_ids) - _TRACE_IDS
if unknown_trace_ids:
raise ValueError(f"unknown trace bindings: {sorted(unknown_trace_ids)}")
evidence_refs = _string_list(entry.get("evidence_refs"), "evidence_refs")
return ControlContract(
**values,
trace_ids=trace_ids,
evidence_refs=evidence_refs,
)
def _string_list(value: object, field: str) -> tuple[str, ...]:
if not isinstance(value, list) or not value or any(
not isinstance(item, str) or not item.strip() for item in value
):
raise ValueError(f"control {field} must be a non-empty list of strings")
return tuple(value)
def _is_local_target(target: str) -> bool:
parsed = urlsplit(target)
return (
target.startswith("/")
and not target.startswith("//")
and not parsed.scheme
and not parsed.netloc
)
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