The safety layer: two presses for anything you cannot take back

Claude-Session: https://claude.ai/code/session_01Ms2FbjQy31TVf3CEvQhGM8
2026-08-25 00:39:07 -04:00
parent 8b1205e4b8
commit 88371d19f0
17 changed files with 447 additions and 36 deletions
@@ -0,0 +1,93 @@
+#!/usr/bin/env bash
+
+# The safety idioms are only worth having if a refactor cannot quietly drop
+# them. This pins the Tier-1 layer:
+#
+#   1. SettingsButton carries its own keyboard contract (Tab stop, Return /
+#      Enter / Space, Accessible role, focus ring) -- the reason no consumer
+#      hand-rolls those any more.
+#   2. ConfirmAction exists, is registered, and every instantiation names an
+#      actionId; the one-armed-at-a-time token it arbitrates through lives on
+#      ShellState. An anonymous ConfirmAction shares "" with every other
+#      anonymous one, which arms them all at once.
+#   3. ErrorRow instantiations bind a message, and NotMeasuredRow
+#      instantiations say `because:` -- a bare "Not measured" invites the
+#      reader to assume zero, and zero is a measurement.
+
+set -uo pipefail
+
+repo_dir="$(cd "$(dirname "${BASH_SOURCE[0]}")/../.." && pwd)"
+qs="$repo_dir/config/dot/quickshell"
+
+fail() { printf 'settings idiom contract: %s\n' "$1" >&2; exit 1; }
+[[ -r "$qs/modules/settings/SettingsButton.qml" ]] || fail "missing SettingsButton.qml"
+
+python3 - "$qs" <<'PY'
+import re, sys, pathlib
+qs = pathlib.Path(sys.argv[1])
+settings = qs / 'modules' / 'settings'
+problems = []
+
+# 1. The button's own keyboard contract.
+button = (settings / 'SettingsButton.qml').read_text()
+for needle, why in [
+    ('activeFocusOnTab', 'no Tab stop'),
+    ('Keys.onReturnPressed', 'Return does nothing'),
+    ('Keys.onSpacePressed', 'Space does nothing'),
+    ('Accessible.role', 'invisible to screen readers'),
+    ('Theme.accentSecondary', 'no focus ring'),
+]:
+    if needle not in button:
+        problems.append(f'SettingsButton.qml: {needle} gone -- {why}')
+
+# 2. ConfirmAction registered, arbitrated through ShellState, always named.
+qmldir = (settings / 'qmldir').read_text()
+for component in ('ConfirmAction', 'ErrorRow', 'NotMeasuredRow'):
+    if not re.search(rf'^{component} ', qmldir, re.M):
+        problems.append(f'qmldir: {component} unregistered -- pages referencing it fail to load')
+
+confirm = (settings / 'ConfirmAction.qml').read_text()
+if 'ShellState.armedConfirm' not in confirm:
+    problems.append('ConfirmAction.qml: not arbitrated through ShellState.armedConfirm -- two rows can be armed at once')
+shellstate = (qs / 'services' / 'ShellState.qml').read_text()
+if 'armedConfirm' not in shellstate:
+    problems.append('ShellState.qml: armedConfirm token gone -- ConfirmAction has nothing to arbitrate through')
+
+# 3. Instantiation-shape checks. A component use spans the braces that follow
+# it; requiring the property inside that span is a cheap parse that has caught
+# every real miss so far.
+def block_after(text, start):
+    depth, i = 0, text.index('{', start)
+    for j in range(i, len(text)):
+        if text[j] == '{': depth += 1
+        elif text[j] == '}':
+            depth -= 1
+            if depth == 0: return text[i:j]
+    return text[i:]
+
+REQUIRED = {'ConfirmAction': 'actionId', 'ErrorRow': 'message', 'NotMeasuredRow': 'because'}
+for page in sorted(qs.rglob('*.qml')):
+    if page.name in ('ConfirmAction.qml', 'ErrorRow.qml', 'NotMeasuredRow.qml'):
+        continue
+    text = page.read_text()
+    for component, prop in REQUIRED.items():
+        for m in re.finditer(rf'\b{component}\s*\{{', text):
+            if not re.search(rf'\b{prop}\s*:', block_after(text, m.start())):
+                problems.append(f'{page.name}: {component} without {prop}:')
+
+if problems:
+    print(f"settings idiom contract: {len(problems)} problem(s)")
+    for p in problems: print("  -", p)
+    sys.exit(1)
+
+uses = {c: 0 for c in REQUIRED}
+for page in qs.rglob('*.qml'):
+    if page.name in ('ConfirmAction.qml', 'ErrorRow.qml', 'NotMeasuredRow.qml'):
+        continue
+    text = page.read_text()
+    for c in uses:
+        uses[c] += len(re.findall(rf'\b{c}\s*\{{', text))
+print("settings idiom contract: ok ("
+      + ", ".join(f"{n} {c}" for c, n in uses.items())
+      + ", every one carries its required property)")
+PY