add support for injecting initial values

tim-smart · Sep 21, 2023 · bcad9a7 · bcad9a7
1 parent 169515b
commit bcad9a7
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Showing 7 changed files with 82 additions and 22 deletions.
diff --git a/.changeset/cool-cycles-hammer.md b/.changeset/cool-cycles-hammer.md
@@ -0,0 +1,5 @@
+---
+"@effect-rx/rx": patch
+---
+
+add support for injecting initial values
diff --git a/docs/rx/Registry.ts.md b/docs/rx/Registry.ts.md
@@ -29,7 +29,9 @@ Added in v1.0.0
 **Signature**
 
 ```ts
-export declare const make: () => Registry
+export declare const make: (
+  options?: { readonly initialValues: Iterable<readonly [Rx.Rx<any>, any]> } | undefined
+) => Registry
 ```
 
 Added in v1.0.0

diff --git a/docs/rx/Rx.ts.md b/docs/rx/Rx.ts.md
@@ -12,7 +12,10 @@ Added in v1.0.0
 
 <h2 class="text-delta">Table of contents</h2>
 
+- [batching](#batching)
+  - [batch](#batch)
 - [combinators](#combinators)
+  - [initialValue](#initialvalue)
   - [keepAlive](#keepalive)
   - [refreshable](#refreshable)
   - [withLabel](#withlabel)
@@ -57,13 +60,36 @@ Added in v1.0.0
   - [TypeId (type alias)](#typeid-type-alias)
   - [WritableTypeId](#writabletypeid)
   - [WritableTypeId (type alias)](#writabletypeid-type-alias)
-- [utils](#utils)
-  - [batch](#batch)
 
 ---
 
+# batching
+
+## batch
+
+**Signature**
+
+```ts
+export declare const batch: (f: () => void) => void
+```
+
+Added in v1.0.0
+
 # combinators
 
+## initialValue
+
+**Signature**
+
+```ts
+export declare const initialValue: {
+  <A>(initialValue: A): (self: Rx<A>) => readonly [Rx<A>, A]
+  <A>(self: Rx<A>, initialValue: A): readonly [Rx<A>, A]
+}
+```
+
+Added in v1.0.0
+
 ## keepAlive
 
 **Signature**
@@ -89,8 +115,10 @@ Added in v1.0.0
 **Signature**
 
 ```ts
-export declare const withLabel: ((name: string) => <A extends Rx<any>>(self: A) => A) &
-  (<A extends Rx<any>>(self: A, name: string) => <A extends Rx<any>>(self: A) => A)
+export declare const withLabel: {
+  (name: string): <A extends Rx<any>>(self: A) => A
+  <A extends Rx<any>>(self: A, name: string): <A extends Rx<any>>(self: A) => A
+}
 ```
 
 Added in v1.0.0
@@ -563,15 +591,3 @@ export type WritableTypeId = typeof WritableTypeId
 ```
 
 Added in v1.0.0
-
-# utils
-
-## batch
-
-**Signature**
-
-```ts
-export declare const batch: (f: () => void) => void
-```
-
-Added in v1.0.0
diff --git a/packages/rx/src/Registry.ts b/packages/rx/src/Registry.ts
@@ -33,4 +33,6 @@ export interface Registry {
  * @since 1.0.0
  * @category constructors
  */
-export const make: () => Registry = internal.make
+export const make: (
+  options?: { readonly initialValues: Iterable<readonly [Rx.Rx<any>, any]> } | undefined
+) => Registry = internal.make
diff --git a/packages/rx/src/Rx.ts b/packages/rx/src/Rx.ts
@@ -716,9 +716,12 @@ export const refreshable = <T extends Rx<any>>(
  * @since 1.0.0
  * @category combinators
  */
-export const withLabel = dual<
+export const withLabel: {
+  (name: string): <A extends Rx<any>>(self: A) => A
+  <A extends Rx<any>>(self: A, name: string): <A extends Rx<any>>(self: A) => A
+} = dual<
   (name: string) => <A extends Rx<any>>(self: A) => A,
-  <A extends Rx<any>>(self: A, name: string) => <A extends Rx<any>>(self: A) => A
+  <A extends Rx<any>>(self: A, name: string) => A
 >(2, (self, name) =>
   Object.assign(Object.create(Object.getPrototypeOf(self)), {
     ...self,
@@ -727,5 +730,18 @@ export const withLabel = dual<
 
 /**
  * @since 1.0.0
+ * @category combinators
+ */
+export const initialValue: {
+  <A>(initialValue: A): (self: Rx<A>) => readonly [Rx<A>, A]
+  <A>(self: Rx<A>, initialValue: A): readonly [Rx<A>, A]
+} = dual<
+  <A>(initialValue: A) => (self: Rx<A>) => readonly [Rx<A>, A],
+  <A>(self: Rx<A>, initialValue: A) => readonly [Rx<A>, A]
+>(2, (self, initialValue) => [self, initialValue])
+
+/**
+ * @since 1.0.0
+ * @category batching
  */
 export const batch: (f: () => void) => void = internalRegistry.batch
diff --git a/packages/rx/src/internal/registry.ts b/packages/rx/src/internal/registry.ts
@@ -14,12 +14,19 @@ function constListener(_: any) {}
 export const TypeId: Registry.TypeId = Symbol.for("@effect-rx/rx/Registry") as Registry.TypeId
 
 /** @internal */
-export const make = (): Registry.Registry => new RegistryImpl()
+export const make = (options?: {
+  readonly initialValues: Iterable<readonly [Rx.Rx<any>, any]>
+}): Registry.Registry => new RegistryImpl(options?.initialValues)
 
 class RegistryImpl implements Registry.Registry {
   readonly [TypeId]: Registry.TypeId
-  constructor() {
+  constructor(initialValues?: Iterable<readonly [Rx.Rx<any>, any]>) {
     this[TypeId] = TypeId
+    if (initialValues !== undefined) {
+      for (const [rx, value] of initialValues) {
+        this.ensureNode(rx).setValue(value)
+      }
+    }
   }
 
   private readonly nodes = new Map<Rx.Rx<any>, Node<any>>()

diff --git a/packages/rx/test/Rx.test.ts b/packages/rx/test/Rx.test.ts
@@ -391,6 +391,18 @@ describe("Rx", () => {
     expect(count).toEqual(1)
     expect(r.get(derived)).toEqual("2b")
   })
+
+  it("initialValues", async () => {
+    const state = Rx.state(0)
+    const r = Registry.make({
+      initialValues: [
+        Rx.initialValue(state, 10)
+      ]
+    })
+    expect(r.get(state)).toEqual(10)
+    await new Promise((resolve) => resolve(null))
+    expect(r.get(state)).toEqual(0)
+  })
 })
 
 interface Counter {