',
True,
),
(
"class-wrapper",
'
',
True,
),
# A rounded clipping wrapper repaints its corners when released; not spill.
(
"rounded-wrapper",
'
',
False,
),
# An authored inline transform must survive the scale pass untouched.
(
"authored-transform",
'
" if wrapper else "",
"svg_style": svg_style,
"markup": markup,
}
def network_isolation_failures(context):
"""Point a page at a local listener four different ways; nothing may connect.
Request routing alone does not stop a WebSocket — verified — which is why the
resolver block exists. This asserts the boundary rather than documenting it.
"""
connections = []
server = socket.socket()
server.setsockopt(socket.SOL_SOCKET, socket.SO_REUSEADDR, 1)
server.bind(("127.0.0.1", 0))
port = server.getsockname()[1]
server.listen(8)
def accept_loop():
while True:
try:
connection, address = server.accept()
except OSError:
return
connections.append(address)
connection.close()
thread = threading.Thread(target=accept_loop, daemon=True)
thread.start()
page = context.new_page()
try:
with tempfile.TemporaryDirectory() as directory:
fixture = Path(directory) / "isolation.html"
fixture.write_text(
"",
encoding="utf-8",
)
page.goto(fixture.as_uri(), wait_until="load")
page.wait_for_timeout(1200)
finally:
page.close()
server.close()
if connections:
return [f"network-isolation: {len(connections)} connection(s) reached a local listener"]
return []
def self_test(context):
page = context.new_page()
failures = []
checks = 0
def flagged(html):
page.set_content(html)
return any(category == "clipped" for category, _ in measure(page))
for name, markup, svg_style, wrapper, expected in SVG_CASES:
checks += 1
if flagged(fixture_html(markup, svg_style, wrapper)) != expected:
failures.append(f"{name}: flagged={not expected}, expected={expected}")
# Paired above/below-fold: identical spill, so a scrolled measurement that
# mixed document and viewport coordinates would disagree with its twin.
for label, filler in (("above-fold", ""), ("below-fold", BELOW_FOLD_FILLER)):
checks += 1
if not flagged(fixture_html(SVG_CASES[0][1], filler=filler)):
failures.append(f"{label}-spill: not caught")
checks += 1
if flagged(fixture_html(SVG_CASES[7][1], filler=BELOW_FOLD_FILLER)):
failures.append("below-fold-clean: false clipped finding")
# The DOM must come back exactly as authored, including inline transforms.
checks += 1
page.set_content(fixture_html(SVG_CASES[0][1], svg_style="transform:rotate(2deg)"))
before = page.evaluate(DOM_STATE_JS)
measure(page)
if page.evaluate(DOM_STATE_JS) != before:
failures.append("dom-restore: markup changed after measuring")
# A *scrolling* ancestor must be reported unmeasurable, not clean.
checks += 1
page.set_content(
fixture_html(SVG_CASES[0][1], wrapper='')
)
if not any(category == "unmeasurable" for category, _ in measure(page)):
failures.append("scrolling-ancestor: no unmeasurable finding")
# Collapsed svg, and a page that scrolls sideways.
checks += 2
page.set_content(
'
', encoding="utf-8")
asset_page.goto(fixture.as_uri(), wait_until="load")
asset_page.wait_for_timeout(300)
asset_page.close()
if not any(category == "missing-asset" for category, _ in asset_findings):
failures.append("missing-asset: check did not fire")
checks += 1
failures += network_isolation_failures(context)
if failures:
print("self-test FAILED:")
for failure in failures:
print(f" {failure}")
return 1
print(f"self-test OK: {checks} cases, no false flags.")
return 0
def main():
args = parse_args()
try:
from playwright.sync_api import sync_playwright
except ImportError:
print(
"Playwright is not installed. Install it with:\n"
" pip install playwright && playwright install chromium",
file=sys.stderr,
)
return 2
paths = shipped_assets() if args.all else args.files
if not paths and not args.self_test:
print("Nothing to check. Pass files, --all or --self-test.", file=sys.stderr)
return 2
total_findings = 0
total_notes = 0
with sync_playwright() as playwright:
try:
browser = launch(playwright, args.fonts)
except Exception as error:
print(
f"Could not launch a browser: {error}\n"
" playwright install chromium\n"
" (or set DIAGRAM_LINT_BROWSER_CHANNEL=chrome to use a system Chrome)",
file=sys.stderr,
)
return 2
# The oracle is pixels, so record which browser produced them.
print(f"Chromium {browser.version}, network: {resolver_rule(args.fonts)}", file=sys.stderr)
context = browser.new_context(viewport=VIEWPORT)
block_network(context, args.fonts)
if args.self_test:
status = self_test(context)
if status or not paths:
browser.close()
return status
for path in paths:
page = context.new_page()
try:
findings = check(page, path)
except Exception as error:
findings = [("render-error", str(error).splitlines()[0])]
finally:
page.close()
findings.sort()
total_findings += sum(1 for category, _ in findings if category not in NOTE_CATEGORIES)
total_notes += sum(1 for category, _ in findings if category in NOTE_CATEGORIES)
if not args.quiet:
shown_path = display_path(path)
for category, message in findings:
print(f"{shown_path}: {category}: {message}")
browser.close()
print(
f"Summary: {len(paths)} file(s) rendered, {total_findings} finding(s), "
f"{total_notes} note(s) (not checked, not failed)."
)
return 1 if total_findings else 0
if __name__ == "__main__":
sys.exit(main())
wide
'
''
)
categories = {category for category, _ in measure(page)}
for expected_category in ("svg-collapsed", "page-overflow"):
if expected_category not in categories:
failures.append(f"{expected_category}: check did not fire")
page.close()
# A missing local asset must surface, not be swallowed with the remote noise.
checks += 1
asset_page = context.new_page()
asset_findings = []
watch(asset_page, asset_findings)
with tempfile.TemporaryDirectory() as directory:
fixture = Path(directory) / "missing-asset.html"
fixture.write_text('', encoding="utf-8")
asset_page.goto(fixture.as_uri(), wait_until="load")
asset_page.wait_for_timeout(300)
asset_page.close()
if not any(category == "missing-asset" for category, _ in asset_findings):
failures.append("missing-asset: check did not fire")
checks += 1
failures += network_isolation_failures(context)
if failures:
print("self-test FAILED:")
for failure in failures:
print(f" {failure}")
return 1
print(f"self-test OK: {checks} cases, no false flags.")
return 0
def main():
args = parse_args()
try:
from playwright.sync_api import sync_playwright
except ImportError:
print(
"Playwright is not installed. Install it with:\n"
" pip install playwright && playwright install chromium",
file=sys.stderr,
)
return 2
paths = shipped_assets() if args.all else args.files
if not paths and not args.self_test:
print("Nothing to check. Pass files, --all or --self-test.", file=sys.stderr)
return 2
total_findings = 0
total_notes = 0
with sync_playwright() as playwright:
try:
browser = launch(playwright, args.fonts)
except Exception as error:
print(
f"Could not launch a browser: {error}\n"
" playwright install chromium\n"
" (or set DIAGRAM_LINT_BROWSER_CHANNEL=chrome to use a system Chrome)",
file=sys.stderr,
)
return 2
# The oracle is pixels, so record which browser produced them.
print(f"Chromium {browser.version}, network: {resolver_rule(args.fonts)}", file=sys.stderr)
context = browser.new_context(viewport=VIEWPORT)
block_network(context, args.fonts)
if args.self_test:
status = self_test(context)
if status or not paths:
browser.close()
return status
for path in paths:
page = context.new_page()
try:
findings = check(page, path)
except Exception as error:
findings = [("render-error", str(error).splitlines()[0])]
finally:
page.close()
findings.sort()
total_findings += sum(1 for category, _ in findings if category not in NOTE_CATEGORIES)
total_notes += sum(1 for category, _ in findings if category in NOTE_CATEGORIES)
if not args.quiet:
shown_path = display_path(path)
for category, message in findings:
print(f"{shown_path}: {category}: {message}")
browser.close()
print(
f"Summary: {len(paths)} file(s) rendered, {total_findings} finding(s), "
f"{total_notes} note(s) (not checked, not failed)."
)
return 1 if total_findings else 0
if __name__ == "__main__":
sys.exit(main())