Ephemeral data, done!

packages/plexus-core/src/collection/collection.ts

@@ -75,6 +75,10 @@ export interface PlexusCollectionConfig<DataType> {
 	 * @default false
 	 * */
 	uniqueGroups?: boolean
+	/**
+	 * How long should a data item be allowed to be stale. will automatically clear and remove the data item this many milliseconds after it was last updated
+	 */
+	decay?: number
 
 	sort?: (a: DataType, b: DataType) => number
 }
@@ -283,7 +287,11 @@ export class CollectionInstance<
 							() => this,
 							this._internalStore._key,
 							dataKey,
-							{ ...item, [this._internalStore._key]: dataKey }
+							{
+								...item,
+								[this._internalStore._key]: dataKey,
+							},
+							{ decay: this.config.decay }
 						)
 						// if we get a valid data instance, add it to the collection
 						if (dataInstance) {
@@ -426,6 +434,7 @@ export class CollectionInstance<
 				{
 					prov: true,
 					unfoundKeyIsUndefined: !this.config.unfoundKeyReturnsProvisional,
+					decay: this.config.decay,
 				}
 			)
 			// if we get an invalid data instance, return undefined

packages/plexus-core/src/collection/data.ts

@@ -14,13 +14,14 @@ export type PlexusGroupWatcher<V extends any = any> = (
 ) => void
 
 interface CollectionDataConfig {
-	prov: boolean
+	prov?: boolean
 	unfoundKeyIsUndefined?: boolean
+	decay?: number
 }
 interface PlexusDataStore {
 	primaryKey: string
 	_wDestroyers: Set<() => void>
-	_config: CollectionDataConfig
+	config: CollectionDataConfig
 }
 
 export type PlexusDataInstance<
@@ -45,6 +46,7 @@ export class CollectionData<
 	private _internalStore: PlexusDataStore
 	private foreignKeyData: Record<string | number | symbol, any> = {}
 	private watchingForeignData: Map<string, () => void>
+	private decayTimeout?: ReturnType<typeof setTimeout>
 
 	constructor(
 		instance: () => PlexusInstance,
@@ -55,20 +57,23 @@ export class CollectionData<
 		config: CollectionDataConfig = { prov: false }
 	) {
 		super(instance, value)
-		this.provisional = config.prov
+		this.provisional = config.prov ?? false
 		this.primaryKey = primaryKey
 		this.key = keyValue + ''
 		this.watchingForeignData = new Map()
 
 		this._internalStore = {
 			primaryKey,
 			_wDestroyers: new Set<() => void>(),
-			_config: config,
+			config: config,
 		}
 		if (!this.provisional) {
 			this.mount()
 			this.syncForeignKeyData(true)
 		}
+		if (config.decay) {
+			this.decay(config.decay)
+		}
 	}
 	/**
 	 * The internal id of the state with an instance prefix
@@ -333,6 +338,24 @@ export class CollectionData<
 		this.instance()._collectionData.delete(this)
 		return this
 	}
+	/**
+	 * Decay this data instance after a certain amount of time
+	 * @param {boolean|string}time The time to decay in ms
+	 * @returns {this} The data instance
+	 */
+	decay(time: number | false) {
+		this.instance().runtime.log(
+			'debug',
+			`Data ${this.instanceId} decaying in ${time}ms...`
+		)
+		if (this.decayTimeout) clearTimeout(this.decayTimeout)
+		if (!time) return this
+
+		this.decayTimeout = setTimeout(() => {
+			this.delete()
+		}, time)
+		return this
+	}
 	/**
 	 * Watch for changes on this data instance
 	 * @callback WatchCallback

tests/collection.test.ts

@@ -1,6 +1,13 @@
 import { beforeEach, afterEach, describe, test, expect } from 'vitest'
 import { collection, instance, PlexusCollectionInstance } from '@plexusjs/core'
-import { appointments, users, uniqueGroups } from './test-utils'
+import {
+	appointments,
+	users,
+	uniqueGroups,
+	decayingUsers,
+	DEFAULT_DECAY_RATE,
+} from './test-utils'
+import { s } from 'vitest/dist/types-63abf2e0'
 
 const myCollection = collection<{
 	thing: string
@@ -205,6 +212,22 @@ describe('Testing Collection', () => {
 		myCollection.collect({ thing: 'lol', id: 0 })
 		expect(myCollection.size).toBe(2)
 	})
+	test(
+		'Does decaying data work?',
+		(ctx) =>
+			new Promise((resolve) => {
+				decayingUsers.collect({ firstName: 'Bill', userId: '0' })
+				expect(decayingUsers.value.length).toBe(1)
+				expect(decayingUsers.value[0].firstName).toBe('Bill')
+				expect(decayingUsers.value[0].userId).toBe('0')
+				setTimeout(() => {
+					expect(decayingUsers.value.length).toBe(0)
+					console.log('done! Thing is decayed!')
+					resolve(true)
+				}, DEFAULT_DECAY_RATE + 10)
+			}),
+		DEFAULT_DECAY_RATE + 100
+	)
 })
 describe('testing collection groups', () => {
 	test('Do Groups Work?', () => {

tests/test-utils.tsx

@@ -59,6 +59,15 @@ export const uniqueGroups = collection<UserLiteExplicitIdName>({
 	uniqueGroups: true
 }).createSelector('batched')
 
+export const DEFAULT_DECAY_RATE = 12_000
+export const decayingUsers = collection<UserLiteExplicitIdName>({
+	primaryKey: 'userId',
+	name: 'userslite',
+	defaultGroup: 'upcoming',
+	uniqueGroups: true,
+	decay: DEFAULT_DECAY_RATE
+}).createSelector('batched')
+
 export const appointments = collection<Appointment>({
 	primaryKey: 'id',
 	name: 'appointments',