Add projection utility and type

packages/client/src/clientData.ts

@@ -2,29 +2,41 @@ import {writable} from "svelte/store"
 import type {Readable, Unsubscriber} from "svelte/store"
 import type {Maybe} from "@welshman/lib"
 import type {Filter} from "@welshman/util"
-import {deriveItems, withGetter, makeDeriveItem, makeLoadItem, makeForceLoadItem} from "@welshman/store"
-import type {
-  ReadableWithGetter,
-  EventToItem,
-  ItemsByKey,
-  MakeLoadItemOptions,
-} from "@welshman/store"
+import {deriveItems, getter, makeDeriveItem, makeLoadItem, makeForceLoadItem} from "@welshman/store"
+import type {EventToItem, ItemsByKey, MakeLoadItemOptions} from "@welshman/store"
 import type {IClient} from "./client.js"
 import {Stores} from "./stores.js"
 
+/**
+ * Utility type which allows for using the same value both for hot gets and derived subscriptions
+ */
+export type Projection<T> = {
+  get: () => T
+  $: Readable<T>
+}
+
+export const projection = <T>($: Readable<T>, get = getter($)) => ({$, get})
+
 /**
  * Base class for a reactive, keyed collection of "local" (non-event) data —
  * things like relay stats or NIP-11 profiles that aren't backed by the
  * repository. The collection owns its own map.
+ *
+ * `index` (map) and `all` (values) are `Projection`s — subscribe via `.$`,
+ * snapshot via `.get()`. Per-key access is `one(key)`, a plain on-demand store
+ * (snapshot with svelte's `get(...)`, or read `get(key)` directly).
  */
 export class ClientData<T> {
-  index = withGetter(writable(new Map<string, T>()))
-  all = withGetter(deriveItems(this.index))
+  protected store = writable(new Map<string, T>())
+  index: Projection<ItemsByKey<T>>
+  all: Projection<T[]>
   one: (key?: string, ...args: any[]) => Readable<Maybe<T>>
   subs: ((key: string, value: Maybe<T>) => void)[] = []
 
   constructor(protected readonly ctx: IClient) {
-    this.one = makeDeriveItem(this.index)
+    this.index = projection(this.store)
+    this.all = projection(deriveItems(this.store))
+    this.one = makeDeriveItem(this.store)
   }
 
   keys = () => this.index.get().keys()
@@ -34,7 +46,7 @@ export class ClientData<T> {
   get = (key: string) => this.index.get().get(key)
 
   set = (key: string, value: T) => {
-    this.index.update($items => {
+    this.store.update($items => {
       $items.set(key, value)
 
       return $items
@@ -44,7 +56,7 @@ export class ClientData<T> {
   }
 
   delete = (key: string) => {
-    this.index.update($items => {
+    this.store.update($items => {
       $items.delete(key)
 
       return $items
@@ -56,7 +68,7 @@ export class ClientData<T> {
   clear = () => {
     const keys = Array.from(this.index.get().keys())
 
-    this.index.set(new Map())
+    this.store.set(new Map())
 
     for (const key of keys) {
       this.emitItem(key, undefined)
@@ -102,7 +114,7 @@ export abstract class LoadableData<T> extends ClientData<T> {
 
     this.load = makeLoadItem(fetch, read, options)
     this.forceLoad = makeForceLoadItem(fetch, read)
-    this.one = makeDeriveItem(this.index, this.load)
+    this.one = makeDeriveItem(this.store, this.load)
   }
 }
 
@@ -119,10 +131,13 @@ export type DerivedDataOptions<T> = {
  * over `ctx.itemsByKey`, never a duplicated map. Subclasses implement `fetch`
  * (how to load an item by key from the network) and pass the filters/decoder via
  * `super`.
+ *
+ * `index` (map) and `all` (values) are `Projection`s — subscribe via `.$`,
+ * snapshot via `.get()`. Per-key access is `one(key)`, a plain on-demand store.
  */
 export abstract class DerivedData<T> {
-  index: ReadableWithGetter<ItemsByKey<T>>
-  all: ReadableWithGetter<T[]>
+  index: Projection<ItemsByKey<T>>
+  all: Projection<T[]>
   one: (key?: string, ...args: any[]) => Readable<Maybe<T>>
   load: (key: string, ...args: any[]) => Promise<Maybe<T>>
   forceLoad: (key: string, ...args: any[]) => Promise<Maybe<T>>
@@ -133,21 +148,21 @@ export abstract class DerivedData<T> {
     protected readonly ctx: IClient,
     options: DerivedDataOptions<T>,
   ) {
-    this.index = withGetter(
-      ctx.use(Stores).itemsByKey<T>({
-        filters: options.filters,
-        eventToItem: options.eventToItem,
-        getKey: options.getKey,
-      }),
-    )
-    this.all = withGetter(deriveItems(this.index))
+    const index = ctx.use(Stores).itemsByKey<T>({
+      filters: options.filters,
+      eventToItem: options.eventToItem,
+      getKey: options.getKey,
+    })
+
+    this.index = projection(index)
+    this.all = projection(deriveItems(index))
 
     const fetch = (key: string, ...args: any[]) => this.fetch(key, ...args)
     const read = (key: string) => this.index.get().get(key)
 
     this.load = makeLoadItem(fetch, read, options.loadOptions)
     this.forceLoad = makeForceLoadItem(fetch, read)
-    this.one = makeDeriveItem(this.index, this.load)
+    this.one = makeDeriveItem(index, this.load)
   }
 
   keys = () => this.index.get().keys()

packages/client/src/feeds.ts

@@ -1,4 +1,3 @@
-import {get} from "svelte/store"
 import {Scope, FeedController} from "@welshman/feeds"
 import type {FeedControllerOptions, Feed} from "@welshman/feeds"
 import type {AdapterContext} from "@welshman/net"
@@ -27,11 +26,11 @@ export class Feeds {
       case Scope.Self:
         return [$pubkey]
       case Scope.Follows:
-        return get(this.ctx.use(Wot).follows($pubkey))
+        return this.ctx.use(Wot).follows($pubkey).get()
       case Scope.Network:
-        return get(this.ctx.use(Wot).network($pubkey))
+        return this.ctx.use(Wot).network($pubkey).get()
       case Scope.Followers:
-        return get(this.ctx.use(Wot).followers($pubkey))
+        return this.ctx.use(Wot).followers($pubkey).get()
       default:
         return []
     }

packages/client/src/handles.ts

@@ -1,8 +1,10 @@
 import {tryCatch, batcher, postJson} from "@welshman/lib"
+import type {Maybe} from "@welshman/lib"
 import {queryProfile, displayNip05} from "@welshman/util"
 import type {Handle} from "@welshman/util"
 import {deriveDeduplicated} from "@welshman/store"
-import {LoadableData} from "./clientData.js"
+import {LoadableData, projection} from "./clientData.js"
+import type {Projection} from "./clientData.js"
 import type {IClient} from "./client.js"
 import {Profiles} from "./profiles.js"
 
@@ -61,20 +63,22 @@ export class Handles extends LoadableData<Handle> {
     return $profile?.nip05 ? this.load($profile.nip05) : undefined
   }
 
-  forPubkey = (pubkey: string, relays: string[] = []) => {
+  forPubkey = (pubkey: string, relays: string[] = []): Projection<Maybe<Handle>> => {
     this.loadForPubkey(pubkey, relays)
 
-    return deriveDeduplicated(
-      [this.index, this.ctx.use(Profiles).one(pubkey, relays)],
-      ([$handlesByNip05, $profile]) => {
-        if (!$profile?.nip05) return undefined
+    const read = ([$handlesByNip05, $profile]: [ReadonlyMap<string, Handle>, Maybe<{nip05?: string}>]) => {
+      if (!$profile?.nip05) return undefined
 
-        const handle = $handlesByNip05.get($profile.nip05)
+      const handle = $handlesByNip05.get($profile.nip05)
 
-        if (handle?.pubkey !== pubkey) return undefined
+      if (handle?.pubkey !== pubkey) return undefined
 
-        return handle
-      },
+      return handle
+    }
+
+    return projection(
+      deriveDeduplicated([this.index.$, this.ctx.use(Profiles).one(pubkey, relays)], read),
+      () => read([this.index.get(), this.ctx.use(Profiles).get(pubkey)]),
     )
   }
 

packages/client/src/profiles.ts

@@ -9,8 +9,9 @@ import {
   PROFILE,
 } from "@welshman/util"
 import type {Profile} from "@welshman/util"
-import type {Readable} from "svelte/store"
-import {DerivedData} from "./clientData.js"
+import type {Maybe} from "@welshman/lib"
+import {DerivedData, projection} from "./clientData.js"
+import type {Projection} from "./clientData.js"
 import {Network} from "./network.js"
 import {Router} from "./router.js"
 import {Thunks} from "./thunk.js"
@@ -41,13 +42,13 @@ export class Profiles extends DerivedData<ReturnType<typeof readProfile>> {
     return this.ctx.use(Thunks).publish({event, relays})
   }
 
-  display = (pubkey: string | undefined, ...args: any[]): Readable<string> =>
-    pubkey ? displayProfile(this.get(pubkey), displayPubkey(pubkey)) : ""
+  display = (pubkey: string | undefined, ...args: any[]): Projection<string> => {
+    const read = ($profile: Maybe<ReturnType<typeof readProfile>>) =>
+      pubkey ? displayProfile($profile, displayPubkey(pubkey)) : ""
 
-  deriveDisplay = (pubkey: string | undefined, ...args: any[]): Readable<string> =>
-    pubkey
-      ? derived(this.one(pubkey, ...args), $profile =>
-          displayProfile($profile, displayPubkey(pubkey)),
-        )
-      : readable("")
+    return projection(
+      pubkey ? derived(this.one(pubkey, ...args), read) : readable(""),
+      () => read(pubkey ? this.get(pubkey) : undefined),
+    )
+  }
 }

packages/client/src/relays.ts

@@ -1,9 +1,10 @@
 import {derived} from "svelte/store"
-import {fetchone} from "@welshman/lib"
+import {fetchJson} from "@welshman/lib"
 import type {Maybe} from "@welshman/lib"
 import {displayRelayUrl, displayRelayProfile} from "@welshman/util"
 import type {RelayProfile} from "@welshman/util"
-import {LoadableData} from "./clientData.js"
+import {LoadableData, projection} from "./clientData.js"
+import type {Projection} from "./clientData.js"
 
 /**
  * NIP-11 relay profiles, keyed by url. A "local" loadable collection: items
@@ -36,8 +37,9 @@ export class Relays extends LoadableData<RelayProfile> {
     }
   }
 
-  display = (url: string) => displayRelayProfile(this.get(url), displayRelayUrl(url))
+  display = (url: string): Projection<string> => {
+    const read = ($relay: Maybe<RelayProfile>) => displayRelayProfile($relay, displayRelayUrl(url))
 
-  deriveDisplay = (url: string) =>
-    derived(this.one(url), $relay => displayRelayProfile($relay, displayRelayUrl(url)))
+    return projection(derived(this.one(url), read), () => read(this.get(url)))
+  }
 }

packages/client/src/search.ts

@@ -69,7 +69,7 @@ export class Searches {
 
   constructor(readonly ctx: IClient) {
     this.profileSearch = derived(
-      [throttled(800, this.ctx.use(Profiles).all), throttled(800, this.ctx.use(Handles).index)],
+      [throttled(800, this.ctx.use(Profiles).all.$), throttled(800, this.ctx.use(Handles).index.$)],
       ([$profiles, $handlesByNip05]) => {
         // Remove invalid nip05's from profiles
         const options = $profiles.map(p => {
@@ -107,7 +107,7 @@ export class Searches {
       }),
     )
 
-    this.relaySearch = derived(this.ctx.use(Relays).all, $relays =>
+    this.relaySearch = derived(this.ctx.use(Relays).all.$, $relays =>
       createSearch($relays, {
         getValue: (relay: RelayProfile) => relay.url,
         fuseOptions: {

packages/client/src/tags.ts

@@ -1,4 +1,3 @@
-import {get} from "svelte/store"
 import {uniq, remove} from "@welshman/lib"
 import {
   getAddress,
@@ -32,7 +31,7 @@ export class Tags {
     "p",
     pubkey,
     this.ctx.use(Router).FromPubkey(pubkey).getUrl() || "",
-    get(this.ctx.use(Profiles).display(pubkey)),
+    this.ctx.use(Profiles).display(pubkey).get(),
   ]
 
   tagEvent = (event: TrustedEvent, url = "", mark = "") => {

packages/client/src/wot.ts

@@ -2,9 +2,9 @@ import {readable, derived} from "svelte/store"
 import {max, throttle, addToMapKey, inc, dec} from "@welshman/lib"
 import {getListTags, getPubkeyTagValues} from "@welshman/util"
 import type {List} from "@welshman/util"
-import {withGetter} from "@welshman/store"
-import type {ReadableWithGetter} from "@welshman/store"
 import type {IClient} from "./client.js"
+import {projection} from "./clientData.js"
+import type {Projection} from "./clientData.js"
 import {FollowLists} from "./follows.js"
 import {MuteLists} from "./mutes.js"
 
@@ -15,96 +15,104 @@ const listPubkeys = (list: List | undefined) => getPubkeyTagValues(getListTags(l
  * built from the perspective of the client's user (or, with no user, the union
  * of every known follow list) and updated reactively as lists change.
  *
- * The aggregate `*ByPubkey`/`graph`/`max` fields are long-lived `withGetter`
- * stores (snapshot with `.get()`). The parameterized methods (`follows`,
- * `wotScore`, …) return plain on-demand stores — snapshot them with svelte's
- * `get(...)`.
+ * The aggregate `*ByPubkey`/`graph`/`max` fields and the parameterized methods
+ * (`follows`, `wotScore`, …) are all `Projection`s — subscribe via `.$`, snapshot
+ * via `.get()`.
  */
 export class Wot {
-  followersByPubkey: ReadableWithGetter<Map<string, Set<string>>>
-  mutersByPubkey: ReadableWithGetter<Map<string, Set<string>>>
-  graph: ReadableWithGetter<Map<string, number>>
-  max: ReadableWithGetter<number | undefined>
+  followersByPubkey: Projection<Map<string, Set<string>>>
+  mutersByPubkey: Projection<Map<string, Set<string>>>
+  graph: Projection<Map<string, number>>
+  max: Projection<number | undefined>
 
   constructor(readonly ctx: IClient) {
-    this.followersByPubkey = withGetter(
-      readable(new Map<string, Set<string>>(), set =>
-        this.ctx.use(FollowLists).index.subscribe(
-          throttle(1000, lists => {
-            const $followersByPubkey = new Map<string, Set<string>>()
+    const followersByPubkeyStore = readable(new Map<string, Set<string>>(), set =>
+      this.ctx.use(FollowLists).index.$.subscribe(
+        throttle(1000, lists => {
+          const $followersByPubkey = new Map<string, Set<string>>()
 
-            for (const list of lists.values()) {
-              for (const pubkey of getPubkeyTagValues(getListTags(list))) {
-                addToMapKey($followersByPubkey, pubkey, list.event.pubkey)
-              }
-            }
-
-            set($followersByPubkey)
-          }),
-        ),
-      ),
-    )
-
-    this.mutersByPubkey = withGetter(
-      readable(new Map<string, Set<string>>(), set =>
-        this.ctx.use(MuteLists).index.subscribe(
-          throttle(1000, lists => {
-            const $mutersByPubkey = new Map<string, Set<string>>()
-
-            for (const list of lists.values()) {
-              for (const pubkey of getPubkeyTagValues(getListTags(list))) {
-                addToMapKey($mutersByPubkey, pubkey, list.event.pubkey)
-              }
-            }
-
-            set($mutersByPubkey)
-          }),
-        ),
-      ),
-    )
-
-    this.graph = withGetter(
-      readable(new Map<string, number>(), set => {
-        const rebuild = throttle(1000, () => {
-          const $followLists = this.ctx.use(FollowLists).index.get()
-          const $muteLists = this.ctx.use(MuteLists).index.get()
-          const $pubkey = this.ctx.user?.pubkey
-          const $graph = new Map<string, number>()
-          const roots = $pubkey ? listPubkeys($followLists.get($pubkey)) : Array.from($followLists.keys())
-
-          for (const follow of roots) {
-            for (const pubkey of listPubkeys($followLists.get(follow))) {
-              $graph.set(pubkey, inc($graph.get(pubkey)))
-            }
-
-            for (const pubkey of listPubkeys($muteLists.get(follow))) {
-              $graph.set(pubkey, dec($graph.get(pubkey)))
+          for (const list of lists.values()) {
+            for (const pubkey of getPubkeyTagValues(getListTags(list))) {
+              addToMapKey($followersByPubkey, pubkey, list.event.pubkey)
             }
           }
 
-          set($graph)
-        })
-
-        const unsubscribers = [
-          this.ctx.use(FollowLists).index.subscribe(rebuild),
-          this.ctx.use(MuteLists).index.subscribe(rebuild),
-        ]
-
-        return () => unsubscribers.forEach(unsubscribe => unsubscribe())
-      }),
+          set($followersByPubkey)
+        }),
+      ),
     )
 
-    this.max = withGetter(derived(this.graph, $g => max(Array.from($g.values()))))
+    const mutersByPubkeyStore = readable(new Map<string, Set<string>>(), set =>
+      this.ctx.use(MuteLists).index.$.subscribe(
+        throttle(1000, lists => {
+          const $mutersByPubkey = new Map<string, Set<string>>()
+
+          for (const list of lists.values()) {
+            for (const pubkey of getPubkeyTagValues(getListTags(list))) {
+              addToMapKey($mutersByPubkey, pubkey, list.event.pubkey)
+            }
+          }
+
+          set($mutersByPubkey)
+        }),
+      ),
+    )
+
+    const graphStore = readable(new Map<string, number>(), set => {
+      const rebuild = throttle(1000, () => {
+        const $followLists = this.ctx.use(FollowLists).index.get()
+        const $muteLists = this.ctx.use(MuteLists).index.get()
+        const $pubkey = this.ctx.user?.pubkey
+        const $graph = new Map<string, number>()
+        const roots = $pubkey ? listPubkeys($followLists.get($pubkey)) : Array.from($followLists.keys())
+
+        for (const follow of roots) {
+          for (const pubkey of listPubkeys($followLists.get(follow))) {
+            $graph.set(pubkey, inc($graph.get(pubkey)))
+          }
+
+          for (const pubkey of listPubkeys($muteLists.get(follow))) {
+            $graph.set(pubkey, dec($graph.get(pubkey)))
+          }
+        }
+
+        set($graph)
+      })
+
+      const unsubscribers = [
+        this.ctx.use(FollowLists).index.$.subscribe(rebuild),
+        this.ctx.use(MuteLists).index.$.subscribe(rebuild),
+      ]
+
+      return () => unsubscribers.forEach(unsubscribe => unsubscribe())
+    })
+
+    const maxStore = derived(graphStore, $g => max(Array.from($g.values())))
+
+    this.followersByPubkey = projection(followersByPubkeyStore)
+    this.mutersByPubkey = projection(mutersByPubkeyStore)
+    this.graph = projection(graphStore)
+    this.max = projection(maxStore)
   }
 
-  follows = (pubkey: string) =>
-    derived(this.ctx.use(FollowLists).index, $lists => listPubkeys($lists.get(pubkey)))
+  follows = (pubkey: string): Projection<string[]> => {
+    const read = ($lists: ReadonlyMap<string, List>) => listPubkeys($lists.get(pubkey))
 
-  mutes = (pubkey: string) =>
-    derived(this.ctx.use(MuteLists).index, $lists => listPubkeys($lists.get(pubkey)))
+    return projection(derived(this.ctx.use(FollowLists).index.$, read), () =>
+      read(this.ctx.use(FollowLists).index.get()),
+    )
+  }
 
-  network = (pubkey: string) =>
-    derived(this.ctx.use(FollowLists).index, $lists => {
+  mutes = (pubkey: string): Projection<string[]> => {
+    const read = ($lists: ReadonlyMap<string, List>) => listPubkeys($lists.get(pubkey))
+
+    return projection(derived(this.ctx.use(MuteLists).index.$, read), () =>
+      read(this.ctx.use(MuteLists).index.get()),
+    )
+  }
+
+  network = (pubkey: string): Projection<string[]> => {
+    const read = ($lists: ReadonlyMap<string, List>) => {
       const pubkeys = new Set(listPubkeys($lists.get(pubkey)))
       const network = new Set<string>()
 
@@ -117,53 +125,95 @@ export class Wot {
       }
 
       return Array.from(network)
-    })
+    }
 
-  followers = (pubkey: string) =>
-    derived(this.followersByPubkey, $followers => Array.from($followers.get(pubkey) || []))
+    return projection(derived(this.ctx.use(FollowLists).index.$, read), () =>
+      read(this.ctx.use(FollowLists).index.get()),
+    )
+  }
 
-  muters = (pubkey: string) =>
-    derived(this.mutersByPubkey, $muters => Array.from($muters.get(pubkey) || []))
+  followers = (pubkey: string): Projection<string[]> => {
+    const read = ($followers: ReadonlyMap<string, Set<string>>) =>
+      Array.from($followers.get(pubkey) || [])
 
-  followsWhoFollow = (pubkey: string, target: string) =>
-    derived(this.ctx.use(FollowLists).index, $lists =>
+    return projection(derived(this.followersByPubkey.$, read), () =>
+      read(this.followersByPubkey.get()),
+    )
+  }
+
+  muters = (pubkey: string): Projection<string[]> => {
+    const read = ($muters: ReadonlyMap<string, Set<string>>) =>
+      Array.from($muters.get(pubkey) || [])
+
+    return projection(derived(this.mutersByPubkey.$, read), () => read(this.mutersByPubkey.get()))
+  }
+
+  followsWhoFollow = (pubkey: string, target: string): Projection<string[]> => {
+    const read = ($lists: ReadonlyMap<string, List>) =>
       listPubkeys($lists.get(pubkey)).filter(other =>
         listPubkeys($lists.get(other)).includes(target),
-      ),
-    )
+      )
 
-  followsWhoMute = (pubkey: string, target: string) =>
-    derived(
-      [this.ctx.use(FollowLists).index, this.ctx.use(MuteLists).index],
-      ([$follows, $mutes]) =>
-        listPubkeys($follows.get(pubkey)).filter(other =>
-          listPubkeys($mutes.get(other)).includes(target),
+    return projection(derived(this.ctx.use(FollowLists).index.$, read), () =>
+      read(this.ctx.use(FollowLists).index.get()),
+    )
+  }
+
+  followsWhoMute = (pubkey: string, target: string): Projection<string[]> => {
+    const read = ($follows: ReadonlyMap<string, List>, $mutes: ReadonlyMap<string, List>) =>
+      listPubkeys($follows.get(pubkey)).filter(other =>
+        listPubkeys($mutes.get(other)).includes(target),
+      )
+
+    return projection(
+      derived(
+        [this.ctx.use(FollowLists).index.$, this.ctx.use(MuteLists).index.$],
+        ([$follows, $mutes]) => read($follows, $mutes),
+      ),
+      () => read(this.ctx.use(FollowLists).index.get(), this.ctx.use(MuteLists).index.get()),
+    )
+  }
+
+  wotScore = (pubkey: string, target: string): Projection<number> => {
+    const read = (
+      $follows: ReadonlyMap<string, List>,
+      $mutes: ReadonlyMap<string, List>,
+      $followers: ReadonlyMap<string, Set<string>>,
+      $muters: ReadonlyMap<string, Set<string>>,
+    ) => {
+      let follows: string[]
+      let mutes: string[]
+
+      if (pubkey) {
+        const theirFollows = listPubkeys($follows.get(pubkey))
+
+        follows = theirFollows.filter(other => listPubkeys($follows.get(other)).includes(target))
+        mutes = theirFollows.filter(other => listPubkeys($mutes.get(other)).includes(target))
+      } else {
+        follows = Array.from($followers.get(target) || [])
+        mutes = Array.from($muters.get(target) || [])
+      }
+
+      return follows.length - mutes.length
+    }
+
+    return projection(
+      derived(
+        [
+          this.ctx.use(FollowLists).index.$,
+          this.ctx.use(MuteLists).index.$,
+          this.followersByPubkey.$,
+          this.mutersByPubkey.$,
+        ],
+        ([$follows, $mutes, $followers, $muters]) => read($follows, $mutes, $followers, $muters),
+      ),
+      () =>
+        read(
+          this.ctx.use(FollowLists).index.get(),
+          this.ctx.use(MuteLists).index.get(),
+          this.followersByPubkey.get(),
+          this.mutersByPubkey.get(),
         ),
     )
-
-  wotScore = (pubkey: string, target: string) =>
-    derived(
-      [
-        this.ctx.use(FollowLists).index,
-        this.ctx.use(MuteLists).index,
-        this.followersByPubkey,
-        this.mutersByPubkey,
-      ],
-      ([$follows, $mutes, $followers, $muters]) => {
-        let follows: string[]
-        let mutes: string[]
-
-        if (pubkey) {
-          const theirFollows = listPubkeys($follows.get(pubkey))
-
-          follows = theirFollows.filter(other => listPubkeys($follows.get(other)).includes(target))
-          mutes = theirFollows.filter(other => listPubkeys($mutes.get(other)).includes(target))
-        } else {
-          follows = Array.from($followers.get(target) || [])
-          mutes = Array.from($muters.get(target) || [])
-        }
-
-        return follows.length - mutes.length
-      },
-    )
+  }
 }

packages/client/src/zappers.ts

@@ -8,10 +8,12 @@ import {
   batcher,
   postJson,
 } from "@welshman/lib"
+import type {Maybe} from "@welshman/lib"
 import {getTagValue, getZapSplits, zapFromEvent} from "@welshman/util"
 import type {Zapper, Zap, TrustedEvent} from "@welshman/util"
 import {deriveDeduplicated, deriveDeduplicatedByValue} from "@welshman/store"
-import {LoadableData} from "./clientData.js"
+import {LoadableData, projection} from "./clientData.js"
+import type {Projection} from "./clientData.js"
 import type {IClient} from "./client.js"
 import {Profiles} from "./profiles.js"
 
@@ -67,13 +69,15 @@ export class Zappers extends LoadableData<Zapper> {
     return $profile?.lnurl ? this.load($profile.lnurl) : undefined
   }
 
-  forPubkey = (pubkey: string, relays: string[] = []) => {
+  forPubkey = (pubkey: string, relays: string[] = []): Projection<Maybe<Zapper>> => {
     this.loadForPubkey(pubkey, relays)
 
-    return deriveDeduplicated(
-      [this.index, this.ctx.use(Profiles).one(pubkey, relays)],
-      ([$zappersByLnurl, $profile]) =>
-        $profile?.lnurl ? $zappersByLnurl.get($profile.lnurl) : undefined,
+    const read = ([$zappersByLnurl, $profile]: [ReadonlyMap<string, Zapper>, Maybe<{lnurl?: string}>]) =>
+      $profile?.lnurl ? $zappersByLnurl.get($profile.lnurl) : undefined
+
+    return projection(
+      deriveDeduplicated([this.index.$, this.ctx.use(Profiles).one(pubkey, relays)], read),
+      () => read([this.index.get(), this.ctx.use(Profiles).get(pubkey)]),
     )
   }
 
@@ -105,7 +109,7 @@ export class Zappers extends LoadableData<Zapper> {
       await Promise.all(zapReceipts.map(zapReceipt => this.validateZapReceipt(zapReceipt, parent))),
     )
 
-  validZapReceipts = (zapReceipts: TrustedEvent[], parent: TrustedEvent): Readable<Zap[]> => {
+  validZapReceipts = (zapReceipts: TrustedEvent[], parent: TrustedEvent): Projection<Zap[]> => {
     const splits = getZapSplits(parent)
     const profiles = this.ctx.use(Profiles)
 
@@ -114,12 +118,7 @@ export class Zappers extends LoadableData<Zapper> {
       this.loadForPubkey(split.pubkey, removeUndefined([split.relay]))
     }
 
-    const stores: Readable<any>[] = [
-      this.index,
-      ...splits.map(split => profiles.one(split.pubkey)),
-    ]
-
-    return deriveDeduplicatedByValue(stores, (values: any[]) => {
+    const read = (values: any[]) => {
       const $zappersByLnurl = values[0] as Map<string, Zapper>
       const $profiles = values.slice(1) as Array<{lnurl?: string} | undefined>
 
@@ -140,6 +139,13 @@ export class Zappers extends LoadableData<Zapper> {
           return zapper ? zapFromEvent(zapReceipt, zapper) : undefined
         }),
       )
-    })
+    }
+
+    const stores: Readable<any>[] = [this.index.$, ...splits.map(split => profiles.one(split.pubkey))]
+
+    return projection(
+      deriveDeduplicatedByValue(stores, read),
+      () => read([this.index.get(), ...splits.map(split => profiles.get(split.pubkey))]),
+    )
   }
 }