Grandfather existing violations

import { grandfatherRule } from "./grandfather-rule.ts";
 
export const noShoutingConstants = grandfatherRule({
  allowedUpTo: new Date("2026-11-10"),
  meta: {
    /* normal rule metadata */
  },
  create(context) {
    /* normal rule listeners */
  },
});
 
// Or wrap a pre-built StrictRule:
const wrapped = grandfatherRule({ allowedUpTo: new Date("2026-11-10"), ...existingRule });

Reports at or before the cutoff are suppressed using the start line's Git author timestamp. An explicit report location takes precedence over the node location. A date-only string means midnight UTC, not the end of that day.

The wrapper blames the actual linted source, including unsaved edits. Changed and uncommitted lines always count as new. Adding lines above an unchanged violation does not change its age. Blame measures when the line last changed, not when the surrounding code first became a violation.

Rules keep their metadata, listeners, options, messages, suggestions and fixes. Suppressed reports do not apply fixes. Git runs lazily on the first report and is reused for subsequent reports from that rule on that file. Each new rule creation reads fresh history/source, including oxlint autofix passes.

Files without history and reports without a known start line are checked. Shallow boundary lines are also checked because their true age is unknown; CI lint/autofix jobs fetch full history. Unexpected Git failures stop linting instead of silently granting exemptions. No Git fetch or write is performed.

The shouting rule uses the example cutoff above. Until that date, committing an edit can make it exempt even though it was flagged while uncommitted. Use a past rollout timestamp when the goal is to block every new committed edit.