feat(bind): nested keys accept optional args

Author: josepot

packages/core/src/bind/connectFactoryObservable.test.tsx

@@ -127,6 +127,13 @@ describe("connectFactoryObservable", () => {
       expect(result.current).toBe(2)
     })
 
+    it("handles optional args correctly", () => {
+      const [, getNumber$] = bind((x: number, y?: number) => of(x + (y ?? 0)))
+
+      expect(getNumber$(5)).toBe(getNumber$(5, undefined))
+      expect(getNumber$(6, undefined)).toBe(getNumber$(6))
+    })
+
     it("suspends the component when the factory-observable hasn't emitted yet.", async () => {
       const [useDelayedNumber] = bind((x: number) => of(x).pipe(delay(50)))
       const Result: React.FC<{ input: number }> = (p) => (

packages/core/src/bind/connectFactoryObservable.ts

@@ -6,53 +6,6 @@ import { useObservable } from "../internal/useObservable"
 import { SUSPENSE } from "../SUSPENSE"
 import { takeUntilComplete } from "../internal/take-until-complete"
 
-class NestedMap<K extends [], V extends Object> {
-  private root: Map<K, any>
-  constructor() {
-    this.root = new Map()
-  }
-
-  get(keys: K[]): V | undefined {
-    let current: any = this.root
-    for (let i = 0; i < keys.length; i++) {
-      current = current.get(keys[i])
-      if (!current) return undefined
-    }
-    return current
-  }
-
-  set(keys: K[], value: V): void {
-    let current: Map<K, any> = this.root
-    let i
-    for (i = 0; i < keys.length - 1; i++) {
-      let nextCurrent = current.get(keys[i])
-      if (!nextCurrent) {
-        nextCurrent = new Map<K, any>()
-        current.set(keys[i], nextCurrent)
-      }
-      current = nextCurrent
-    }
-    current.set(keys[i], value)
-  }
-
-  delete(keys: K[]): void {
-    const maps: Map<K, any>[] = [this.root]
-    let current: Map<K, any> = this.root
-
-    for (let i = 0; i < keys.length - 1; i++) {
-      maps.push((current = current.get(keys[i])))
-    }
-
-    let mapIdx = maps.length - 1
-    maps[mapIdx].delete(keys[mapIdx])
-
-    while (--mapIdx > -1 && maps[mapIdx].get(keys[mapIdx]).size === 0) {
-      maps[mapIdx].delete(keys[mapIdx])
-    }
-  }
-}
-
-const emptyInput = [0]
 /**
  * Accepts: A factory function that returns an Observable.
  *
@@ -87,7 +40,10 @@ export default function connectFactoryObservable<A extends [], O>(
   const getSharedObservables$ = (
     input: A,
   ): [Observable<O>, BehaviorObservable<O>] => {
-    const keys = input.length > 0 ? input : (emptyInput as A)
+    for (let i = input.length - 1; input[i] === undefined && i > -1; i--) {
+      input.splice(-1)
+    }
+    const keys = ([input.length, ...input] as any) as A
     const cachedVal = cache.get(keys)
 
     if (cachedVal !== undefined) {
@@ -117,3 +73,49 @@ export default function connectFactoryObservable<A extends [], O>(
     (...input: A) => getSharedObservables$(input)[0],
   ]
 }
+
+class NestedMap<K extends [], V extends Object> {
+  private root: Map<K, any>
+  constructor() {
+    this.root = new Map()
+  }
+
+  get(keys: K[]): V | undefined {
+    let current: any = this.root
+    for (let i = 0; i < keys.length; i++) {
+      current = current.get(keys[i])
+      if (!current) return undefined
+    }
+    return current
+  }
+
+  set(keys: K[], value: V): void {
+    let current: Map<K, any> = this.root
+    let i
+    for (i = 0; i < keys.length - 1; i++) {
+      let nextCurrent = current.get(keys[i])
+      if (!nextCurrent) {
+        nextCurrent = new Map<K, any>()
+        current.set(keys[i], nextCurrent)
+      }
+      current = nextCurrent
+    }
+    current.set(keys[i], value)
+  }
+
+  delete(keys: K[]): void {
+    const maps: Map<K, any>[] = [this.root]
+    let current: Map<K, any> = this.root
+
+    for (let i = 0; i < keys.length - 1; i++) {
+      maps.push((current = current.get(keys[i])))
+    }
+
+    let mapIdx = maps.length - 1
+    maps[mapIdx].delete(keys[mapIdx])
+
+    while (--mapIdx > -1 && maps[mapIdx].get(keys[mapIdx]).size === 0) {
+      maps[mapIdx].delete(keys[mapIdx])
+    }
+  }
+}

packages/core/src/bind/index.ts

@@ -46,18 +46,12 @@ export function bind<T>(
  * subscription, then the hook will leverage React Suspense while it's waiting
  * for the first value.
  */
-export function bind<
-  A extends (number | string | boolean | null | Object | Symbol)[],
-  O
->(
+export function bind<A extends unknown[], O>(
   getObservable: (...args: A) => Observable<O>,
   unsubscribeGraceTime?: number,
 ): [(...args: A) => Exclude<O, typeof SUSPENSE>, (...args: A) => Observable<O>]
 
-export function bind<
-  A extends (number | string | boolean | null | Object | Symbol)[],
-  O
->(
+export function bind<A extends unknown[], O>(
   obs: ((...args: A) => Observable<O>) | Observable<O>,
   unsubscribeGraceTime = 200,
 ) {