style: format recurrence helpers

src/components/recurrence-picker.tsx

@@ -15,11 +15,11 @@ import {
 	getRecurrencePreview,
 	getWeekdayOptions,
 	parseRecurrenceRule,
+	type RecurrenceFormValue,
 	recurrenceFrequencyLabels,
+	type SupportedRecurrenceFrequency,
 	serializeRecurrenceRule,
 	validateRecurrence,
-	type RecurrenceFormValue,
-	type SupportedRecurrenceFrequency,
 	type Weekday,
 } from "@/lib/recurrence";
 
@@ -39,10 +39,7 @@ const getStartWeekday = (start?: string): Weekday => {
 	return weekdays[jsDay] ?? "MO";
 };
 
-const updateWeekdays = (
+const updateWeekdays = (current: Weekday[], day: Weekday): Weekday[] => {
-	current: Weekday[],
-	day: Weekday,
-): Weekday[] => {
 	return current.includes(day)
 		? current.filter((existingDay) => existingDay !== day)
 		: [...current, day];
@@ -95,11 +92,13 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 						<SelectValue />
 					</SelectTrigger>
 					<SelectContent>
-						{Object.entries(recurrenceFrequencyLabels).map(([optionValue, label]) => (
+						{Object.entries(recurrenceFrequencyLabels).map(
+							([optionValue, label]) => (
 								<SelectItem key={optionValue} value={optionValue}>
 									{label}
 								</SelectItem>
-						))}
+							),
+						)}
 					</SelectContent>
 				</Select>
 			</div>
@@ -108,7 +107,12 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 				<>
 					<div>
 						<Label htmlFor="interval" className="text-xs text-muted-foreground">
-							Interval (every {recurrence.interval} {recurrence.freq === "DAILY" ? "day" : recurrence.freq === "WEEKLY" ? "week" : "month"}
+							Interval (every {recurrence.interval}{" "}
+							{recurrence.freq === "DAILY"
+								? "day"
+								: recurrence.freq === "WEEKLY"
+									? "week"
+									: "month"}
 							{recurrence.interval > 1 ? "s" : ""})
 						</Label>
 						<Input
@@ -117,7 +121,9 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 							min={1}
 							value={recurrence.interval}
 							onChange={(event) =>
-								update({ interval: Number.parseInt(event.target.value, 10) || 1 })
+								update({
+									interval: Number.parseInt(event.target.value, 10) || 1,
+								})
 							}
 							className="mt-1.5 w-24"
 						/>
@@ -125,7 +131,9 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 
 					{recurrence.freq === "WEEKLY" && (
 						<div>
-							<Label className="text-xs text-muted-foreground">Days of the week</Label>
+							<Label className="text-xs text-muted-foreground">
+								Days of the week
+							</Label>
 							<div className="mt-1.5 flex flex-wrap gap-3">
 								{weekdayOptions.map(({ value: day, label }) => (
 									<div key={day} className="flex items-center gap-1.5">
@@ -136,7 +144,10 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 												update({ byDay: updateWeekdays(recurrence.byDay, day) })
 											}
 										/>
-										<Label htmlFor={day} className="cursor-pointer text-xs font-normal">
+										<Label
+											htmlFor={day}
+											className="cursor-pointer text-xs font-normal"
+										>
 											{label}
 										</Label>
 									</div>
@@ -186,10 +197,14 @@ export function RecurrencePicker({ value, start, onChange }: Props) {
 					</div>
 
 					{validation.errors.count && (
-						<p className="text-xs text-destructive">{validation.errors.count}</p>
+						<p className="text-xs text-destructive">
+							{validation.errors.count}
+						</p>
 					)}
 					{validation.errors.until && (
-						<p className="text-xs text-destructive">{validation.errors.until}</p>
+						<p className="text-xs text-destructive">
+							{validation.errors.until}
+						</p>
 					)}
 					{validation.errors.rule && (
 						<p className="text-xs text-destructive">{validation.errors.rule}</p>

src/components/rrule-display.tsx

@@ -1,6 +1,10 @@
 import { format, parseISO } from "date-fns";
 import { Badge } from "@/components/ui/badge";
-import { formatRecurrenceText, getRecurrencePreview, parseRecurrenceRule } from "@/lib/recurrence";
+import {
+	formatRecurrenceText,
+	getRecurrencePreview,
+	parseRecurrenceRule,
+} from "@/lib/recurrence";
 
 interface RRuleDisplayProps {
 	rrule?: string;
@@ -12,17 +16,25 @@ export function RRuleDisplay({ rrule, className, start }: RRuleDisplayProps) {
 	if (!rrule) return null;
 
 	const humanText = formatRecurrenceText(rrule);
-	const preview = start ? getRecurrencePreview(parseRecurrenceRule(rrule), start, 3) : [];
+	const preview = start
+		? getRecurrencePreview(parseRecurrenceRule(rrule), start, 3)
+		: [];
 
 	return (
 		<div className={className}>
 			<div className="flex flex-wrap items-center gap-1.5">
-				<Badge variant="secondary" className="h-5 text-[10px] font-normal capitalize">
+				<Badge
+					variant="secondary"
+					className="h-5 text-[10px] font-normal capitalize"
+				>
 					{humanText ?? rrule}
 				</Badge>
 				{preview.length > 0 && (
 					<Badge variant="outline" className="h-5 text-[10px] font-normal">
-						Next: {preview.map((value) => format(parseISO(value), "MMM d")).join(", ")}
+						Next:{" "}
+						{preview
+							.map((value) => format(parseISO(value), "MMM d"))
+							.join(", ")}
 					</Badge>
 				)}
 			</div>

src/lib/event-date-format.ts

@@ -1,10 +1,4 @@
-import {
+import { format, isSameDay, isToday, isTomorrow, parseISO } from "date-fns";
-	format,
-	isSameDay,
-	isToday,
-	isTomorrow,
-	parseISO,
-} from "date-fns";
 import type { CalendarEvent } from "@/lib/types";
 
 const getFriendlyDayLabel = (value: Date): string => {
@@ -13,7 +7,10 @@ const getFriendlyDayLabel = (value: Date): string => {
 	return format(value, "MMM d, yyyy");
 };
 
-export const formatEventStartLabel = (start: string, allDay?: boolean): string => {
+export const formatEventStartLabel = (
+	start: string,
+	allDay?: boolean,
+): string => {
 	const parsed = parseISO(start);
 	const dayLabel = getFriendlyDayLabel(parsed);
 
@@ -21,12 +18,16 @@ export const formatEventStartLabel = (start: string, allDay?: boolean): string =
 	return `${dayLabel} · ${format(parsed, "HH:mm")}`;
 };
 
-export const formatEventRangeLabel = (event: Pick<CalendarEvent, "start" | "end" | "allDay">): string => {
+export const formatEventRangeLabel = (
+	event: Pick<CalendarEvent, "start" | "end" | "allDay">,
+): string => {
 	const startDate = parseISO(event.start);
 	const startLabel = getFriendlyDayLabel(startDate);
 
 	if (event.allDay || !event.end) {
-		return event.allDay ? startLabel : `${startLabel} · ${format(startDate, "HH:mm")}`;
+		return event.allDay
+			? startLabel
+			: `${startLabel} · ${format(startDate, "HH:mm")}`;
 	}
 
 	const endDate = parseISO(event.end);

src/lib/event-form.ts

@@ -39,7 +39,10 @@ const eventFormSchema = z
 		if (value.end) {
 			const startDate = parseISO(value.start);
 			const endDate = parseISO(value.end);
-			if (Number.isNaN(startDate.getTime()) || Number.isNaN(endDate.getTime())) {
+			if (
+				Number.isNaN(startDate.getTime()) ||
+				Number.isNaN(endDate.getTime())
+			) {
 				ctx.addIssue({
 					code: z.ZodIssueCode.custom,
 					path: ["end"],

src/lib/recurrence.ts

@@ -2,7 +2,11 @@ import { format, parseISO } from "date-fns";
 import { RRule, rrulestr } from "rrule";
 import type { Frequency, Weekday } from "@/lib/rfc5545-types";
 
-export type SupportedRecurrenceFrequency = "NONE" | "DAILY" | "WEEKLY" | "MONTHLY";
+export type SupportedRecurrenceFrequency =
+	| "NONE"
+	| "DAILY"
+	| "WEEKLY"
+	| "MONTHLY";
 
 export interface RecurrenceFormValue {
 	freq: SupportedRecurrenceFrequency;
@@ -23,7 +27,10 @@ const EMPTY_RECURRENCE: RecurrenceFormValue = {
 	byDay: [],
 };
 
-const RULE_FREQUENCIES: Record<Exclude<SupportedRecurrenceFrequency, "NONE">, number> = {
+const RULE_FREQUENCIES: Record<
+	Exclude<SupportedRecurrenceFrequency, "NONE">,
+	number
+> = {
 	DAILY: RRule.DAILY,
 	WEEKLY: RRule.WEEKLY,
 	MONTHLY: RRule.MONTHLY,
@@ -58,7 +65,10 @@ const sortWeekdays = (days: string[] | undefined): Weekday[] => {
 	if (!days?.length) return [];
 	return [...days]
 		.filter((day): day is Weekday => WEEKDAY_ORDER.includes(day as Weekday))
-		.sort((left, right) => WEEKDAY_ORDER.indexOf(left) - WEEKDAY_ORDER.indexOf(right));
+		.sort(
+			(left, right) =>
+				WEEKDAY_ORDER.indexOf(left) - WEEKDAY_ORDER.indexOf(right),
+		);
 };
 
 const toUntilDate = (until: string): Date => {
@@ -105,7 +115,10 @@ export const validateRecurrence = (
 		errors.rule = "Interval must be at least 1.";
 	}
 
-	if (value.count !== undefined && (!Number.isInteger(value.count) || value.count < 1)) {
+	if (
+		value.count !== undefined &&
+		(!Number.isInteger(value.count) || value.count < 1)
+	) {
 		errors.count = "Count must be a whole number greater than 0.";
 	}
 
@@ -164,14 +177,22 @@ export const serializeRecurrenceRule = (
 
 	const validation = validateRecurrence(value);
 	if (!validation.isValid) {
-		throw new Error(validation.errors.rule || validation.errors.count || validation.errors.until || "Invalid recurrence.");
+		throw new Error(
+			validation.errors.rule ||
+				validation.errors.count ||
+				validation.errors.until ||
+				"Invalid recurrence.",
+		);
 	}
 
 	const options = toRRuleOptions(value, dtstart);
 	if (!options) return undefined;
 
 	const rule = new RRule(options);
-	const ruleLine = rule.toString().split("\n").find((line) => line.startsWith("RRULE:"));
+	const ruleLine = rule
+		.toString()
+		.split("\n")
+		.find((line) => line.startsWith("RRULE:"));
 	if (!ruleLine) return undefined;
 
 	const entries = ruleLine.replace(/^RRULE:/, "").split(";");
@@ -181,9 +202,14 @@ export const serializeRecurrenceRule = (
 		const rightKey = right.split("=")[0] ?? "";
 		const leftIndex = orderedKeys.indexOf(leftKey);
 		const rightIndex = orderedKeys.indexOf(rightKey);
-		const normalizedLeftIndex = leftIndex === -1 ? Number.MAX_SAFE_INTEGER : leftIndex;
+		const normalizedLeftIndex =
-		const normalizedRightIndex = rightIndex === -1 ? Number.MAX_SAFE_INTEGER : rightIndex;
+			leftIndex === -1 ? Number.MAX_SAFE_INTEGER : leftIndex;
-		return normalizedLeftIndex - normalizedRightIndex || leftKey.localeCompare(rightKey);
+		const normalizedRightIndex =
+			rightIndex === -1 ? Number.MAX_SAFE_INTEGER : rightIndex;
+		return (
+			normalizedLeftIndex - normalizedRightIndex ||
+			leftKey.localeCompare(rightKey)
+		);
 	});
 
 	return sorted.join(";");
@@ -213,7 +239,10 @@ export const formatRecurrenceText = (rule?: string): string | null => {
 	return rrulestr(`RRULE:${rule}`).toText();
 };
 
-export const getWeekdayOptions = (): Array<{ value: Weekday; label: string }> => [
+export const getWeekdayOptions = (): Array<{
+	value: Weekday;
+	label: string;
+}> => [
 	{ value: "MO", label: "Mon" },
 	{ value: "TU", label: "Tue" },
 	{ value: "WE", label: "Wed" },
@@ -228,7 +257,10 @@ export const isWeekdayPreset = (value: RecurrenceFormValue): boolean =>
 	value.interval === 1 &&
 	value.byDay.join(",") === ["MO", "TU", "WE", "TH", "FR"].join(",");
 
-export const recurrenceFrequencyLabels: Record<SupportedRecurrenceFrequency, string> = {
+export const recurrenceFrequencyLabels: Record<
+	SupportedRecurrenceFrequency,
+	string
+> = {
 	NONE: "Does not repeat",
 	DAILY: "Daily",
 	WEEKLY: "Weekly",