Add method to reset cache (#1107)

Co-authored-by: Alec Aivazis <[email protected]>

.changeset/nine-pillows-greet.md

@@ -0,0 +1,5 @@
+---
+'houdini': patch
+---
+
+Add method to reset cache state

packages/houdini/src/runtime/cache/cache.ts

@@ -274,6 +274,27 @@ export class Cache {
 		this.#notifySubscribers(toNotify)
 	}
 
+	// reset the whole cache
+	reset() {
+		// Reset Subscriptions
+		const subSpecs = this._internal_unstable.subscriptions.reset()
+
+		// Reset StaleManager
+		this._internal_unstable.staleManager.reset()
+
+		// Reset GarbageCollector
+		this._internal_unstable.lifetimes.reset()
+
+		// Reset Lists
+		this._internal_unstable.lists.reset()
+
+		// Reset InMemory Storage
+		this._internal_unstable.storage.reset()
+
+		// Notify Subscribers
+		this.#notifySubscribers(subSpecs)
+	}
+
 	#notifySubscribers(subs: SubscriptionSpec[]) {
 		// if there's no one to notify, its a no-op
 		if (subs.length === 0) {

packages/houdini/src/runtime/cache/gc.ts

@@ -14,6 +14,10 @@ export class GarbageCollector {
 		this.cache = cache
 	}
 
+	reset() {
+		this.lifetimes.clear()
+	}
+
 	resetLifetime(id: string, field: string) {
 		// if this is the first time we've seen the id
 		if (!this.lifetimes.get(id)) {

packages/houdini/src/runtime/cache/lists.ts

@@ -144,6 +144,11 @@ export class ListManager {
 		// delete the lists by field lookups
 		this.listsByField.get(parentID)!.delete(field)
 	}
+
+	reset() {
+		this.lists.clear()
+		this.listsByField.clear()
+	}
 }
 
 export class List {

packages/houdini/src/runtime/cache/staleManager.ts

@@ -108,4 +108,8 @@ export class StaleManager {
 			}
 		}
 	}
+
+	reset() {
+		this.fieldsTime.clear()
+	}
 }

packages/houdini/src/runtime/cache/storage.ts

@@ -289,6 +289,10 @@ export class InMemoryStorage {
 		layer.fields = fields
 		layer.links = links
 	}
+
+	reset() {
+		this.data = []
+	}
 }
 
 export class Layer {

packages/houdini/src/runtime/cache/subscription.ts

@@ -6,7 +6,7 @@ import type {
 	SubscriptionSpec,
 	NestedList,
 } from '../lib/types'
-import type { Cache } from './cache'
+import { rootID, type Cache } from './cache'
 import { evaluateKey } from './stuff'
 
 export type FieldSelection = [
@@ -344,6 +344,25 @@ export class InMemorySubscriptions {
 		}
 	}
 
+	reset() {
+		// Get all subscriptions that do not start with the rootID
+		const subscribers = Object.entries(this.subscribers).filter(
+			([id]) => !id.startsWith(rootID)
+		)
+
+		// Remove those subcribers from this.subscribers
+		for (const [id, _fields] of subscribers) {
+			delete this.subscribers[id]
+		}
+
+		// Get list of all SubscriptionSpecs of subscribers
+		const subscriptionSpecs = subscribers.flatMap(([_id, fields]) =>
+			Object.values(fields).flatMap((field) => field.map(([spec]) => spec))
+		)
+
+		return subscriptionSpecs
+	}
+
 	private removeSubscribers(id: string, fieldName: string, specs: SubscriptionSpec[]) {
 		// build up a list of the sets we actually need to remove after
 		// checking reference counts

packages/houdini/src/runtime/cache/tests/reset.test.ts

@@ -0,0 +1,245 @@
+import { test, expect, vi } from 'vitest'
+
+import { testConfigFile } from '../../../test'
+import { RefetchUpdateMode, type SubscriptionSelection } from '../../lib'
+import { Cache } from '../cache'
+
+const config = testConfigFile()
+
+test('make sure the cache data was reset', function () {
+	const cache = new Cache(config)
+
+	// save the data
+	const data = {
+		viewer: {
+			id: '1',
+			firstName: 'bob',
+		},
+	}
+
+	const selection: SubscriptionSelection = {
+		fields: {
+			viewer: {
+				type: 'User',
+				visible: true,
+				keyRaw: 'viewer',
+				selection: {
+					fields: {
+						id: {
+							type: 'ID',
+							visible: true,
+							keyRaw: 'id',
+						},
+						firstName: {
+							type: 'String',
+							visible: true,
+							keyRaw: 'firstName',
+						},
+					},
+				},
+			},
+		},
+	}
+
+	cache.write({
+		selection,
+		data,
+	})
+
+	// reset the cache
+	cache.reset()
+
+	// make sure the data is gone
+	expect(cache.read({ selection }).data).toBe(null)
+})
+
+test('make sure the cache lists were reset', function () {
+	const cache = new Cache(config)
+
+	const selection: SubscriptionSelection = {
+		fields: {
+			viewer: {
+				type: 'User',
+				visible: true,
+				keyRaw: 'viewer',
+				selection: {
+					fields: {
+						id: {
+							type: 'ID',
+							visible: true,
+							keyRaw: 'id',
+						},
+						friends: {
+							type: 'User',
+							visible: true,
+							keyRaw: 'friends',
+							updates: [RefetchUpdateMode.append],
+							list: {
+								name: 'All_Users',
+								connection: false,
+								type: 'User',
+							},
+							selection: {
+								fields: {
+									id: {
+										type: 'ID',
+										visible: true,
+										keyRaw: 'id',
+									},
+									firstName: {
+										type: 'String',
+										visible: true,
+										keyRaw: 'firstName',
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	cache.write({
+		selection,
+		data: {
+			viewer: {
+				id: '1',
+				friends: [
+					{
+						id: '2',
+						firstName: 'jane',
+					},
+					{
+						id: '3',
+						firstName: 'joe',
+					},
+				],
+			},
+		},
+		applyUpdates: [RefetchUpdateMode.append],
+	})
+	const set = vi.fn()
+	cache.subscribe({
+		rootType: 'Query',
+		set,
+		selection,
+	})
+
+	expect(() => cache.list('All_Users')).toBeDefined()
+
+	// reset the cache
+	cache.reset()
+
+	// make sure the list doesn't exist
+	expect(() => cache.list('All_Users')).toThrowError('Cannot find list with name')
+})
+
+test('make sure the cache subscribers were reset', function () {
+	const cache = new Cache(config)
+
+	const selection: SubscriptionSelection = {
+		fields: {
+			viewer: {
+				type: 'User',
+				visible: true,
+				keyRaw: 'viewer',
+				selection: {
+					fields: {
+						id: {
+							type: 'ID',
+							visible: true,
+							keyRaw: 'id',
+						},
+						firstName: {
+							type: 'String',
+							visible: true,
+							keyRaw: 'firstName',
+						},
+						friends: {
+							type: 'User',
+							visible: true,
+							keyRaw: 'friends',
+							updates: [RefetchUpdateMode.append],
+							selection: {
+								fields: {
+									id: {
+										type: 'ID',
+										visible: true,
+										keyRaw: 'id',
+									},
+									firstName: {
+										type: 'String',
+										visible: true,
+										keyRaw: 'firstName',
+									},
+								},
+							},
+						},
+					},
+				},
+			},
+		},
+	}
+
+	// subscribe to the cache
+	const set = vi.fn()
+	cache.subscribe({
+		rootType: 'Query',
+		set,
+		selection,
+	})
+
+	// reset the cache
+	cache.reset()
+
+	// write the data again
+	cache.write({
+		parent: 'User:1',
+		selection,
+		data: {
+			viewer: {
+				id: '1',
+				firstName: 'bob',
+				friends: [
+					{
+						id: '2',
+						firstName: 'jane',
+					},
+					{
+						id: '3',
+						firstName: 'joe',
+					},
+				],
+			},
+		},
+		applyUpdates: [RefetchUpdateMode.append],
+	})
+
+	// make sure the subscriber was not called
+	expect(set).not.toHaveBeenCalled()
+
+	cache.write({
+		selection,
+		data: {
+			viewer: {
+				id: '1',
+				firstName: 'bob',
+				friends: [
+					{
+						id: '4',
+						firstName: 'mary',
+					},
+					{
+						id: '5',
+						firstName: 'jill',
+					},
+				],
+			},
+		},
+		applyUpdates: [RefetchUpdateMode.append],
+	})
+
+	// make sure the root subscriber was called because parent was not defined
+	expect(set).toHaveBeenCalled()
+})

packages/houdini/src/runtime/public/cache.ts

@@ -124,4 +124,12 @@ Please acknowledge this by setting acceptImperativeInstability to true in your c
 	): void {
 		return this._internal_unstable.markTypeStale(type ? { ...options, type } : undefined)
 	}
+
+	/**
+	 * Reset the entire cache by clearing all records and lists
+	 */
+
+	reset(): void {
+		return this._internal_unstable.reset()
+	}
 }

site/src/routes/api/cache/+page.svx

@@ -324,3 +324,14 @@ user.markStale('name')
 const user = cache.get('User', { id: '1' })
 user.markStale('name' { when: { pattern: 'capitalize' } })
 ```
+
+## Resetting the Cache
+
+In some situations, it is necessary to reset the cache to a totally blank state. To do this, you
+should use the `reset` method:
+
+```typescript
+import { cache } from '$houdini'
+
+cache.reset()
+```