Implement ClientSchedule state tracking class

Write the logic of keeping track of location modifications and applying
updates from the server into the ClientSchedule class.  This should
serve as the foundation for replacing the prototype in-component update
logic which have turned into an unmaintainable spagetti.

shared/types/common.ts

@@ -8,7 +8,7 @@ export const entityLivingSchema = z.object({
 	updatedAt: z.string(),
 	deleted: z.optional(z.literal(false)),
 });
-export type EnityLiving = z.infer<typeof entityLivingSchema>;
+export type EntityLiving = z.infer<typeof entityLivingSchema>;
 
 export const entityToombstoneSchema = z.object({
 	id: idSchema,
@@ -20,6 +20,9 @@ export type EntityToombstone = z.infer<typeof entityToombstoneSchema>;
 export const entitySchema = z.discriminatedUnion("deleted", [entityLivingSchema, entityToombstoneSchema]);
 export type Entity = z.infer<typeof entitySchema>;
 
+export type Living<T extends Entity> = Extract<T, { deleted?: false }>;
+export type Tombstone<T extends Entity> = Extract<T, { deleted: true }>;
+
 export function defineEntity<T extends {}>(fields: T) {
 	return z.discriminatedUnion("deleted", [z.extend(entityLivingSchema, fields), entityToombstoneSchema]);
 }

shared/utils/functions.ts

@@ -32,6 +32,29 @@ export function* pairs<T>(iterable: Iterable<T>) {
 	}
 }
 
+/**
+	Returns true if the two arrays passed as input compare equal to each other.
+	@param a Input array
+	@param b Input array
+	@param equals Function to compare individual elements in the array.
+	@returns True if the arrays compare equal
+*/
+export function arrayEquals<T>(
+	a: T[],
+	b: T[],
+	equals: (a: T, b: T) => unknown = (a, b) => a === b,
+) {
+	if (a.length !== b.length) {
+		return false;
+	}
+	for (let i = 0; i < a.length; i++) {
+		if (!equals(a[i], b[i])) {
+			return false;
+		}
+	}
+	return true;
+}
+
 /**
 	Returns true if all sets are equal
 	@param sets set to compare

shared/utils/luxon.ts

@@ -0,0 +1,11 @@
+// Wrapper around Luxon to make sure the throwOnInvalid option is set
+import { Settings, DateTime, FixedOffsetZone, Zone } from "luxon";
+
+Settings.throwOnInvalid = true;
+declare module 'luxon' {
+	interface TSSettings {
+		throwOnInvalid: true;
+	}
+}
+
+export { DateTime, FixedOffsetZone, Zone }