feat: add pChain

Author: hunghg255

.github/workflows/deploy-docs.yml

@@ -3,10 +3,11 @@ name: Vercel Deployment Development
 env:
   VERCEL_ORG_ID: ${{ secrets.VERCEL_ORG_ID }}
   VERCEL_PROJECT_ID: ${{ secrets.VERCEL_PROJECT_ID }}
+
 on:
   push:
-    branches:
-      - main
+    tags:
+      - 'v*'
 
 # This is what will cancel the workflow
 concurrency:

docs/.vitepress/locale.ts

@@ -158,7 +158,10 @@ export function getLocaleConfig(lang: string) {
         },
         {
           text: t('Promise Utilities'),
-          items: [{ text: 'delay', link: '/reference/promise/delay' }],
+          items: [
+            { text: 'delay', link: '/reference/promise/delay' },
+            { text: 'pChain', link: '/reference/promise/pChain' },
+          ],
         },
         {
           text: t('String Utilities'),

docs/package.json

@@ -20,7 +20,7 @@
     "@nolebase/vitepress-plugin-highlight-targeted-heading": "^2.2.1",
     "@shikijs/vitepress-twoslash": "^1.10.3",
     "@vitejs/plugin-vue-jsx": "^4.0.0",
-    "js-utils-es": "^1.0.5",
+    "js-utils-es": "^1.0.6",
     "unocss": "^0.61.3",
     "vite": "^5.3.3",
     "vitepress": "^1.3.0",

docs/reference/promise/pChain.md

@@ -0,0 +1,51 @@
+# pChain
+
+Utility for managing multiple promises.
+
+## Signature
+
+```typescript
+function pChain<T = any>(items?: Iterable<T>): PInstance<T>;
+```
+
+### Parameters
+
+- `items` (`Iterable`): An optional iterable of items to chain.
+
+### Returns
+
+(`PInstance<void>`): A `PInstance` object that can be used to chain promises.
+
+## Description
+
+```ts
+declare class PInstance<T = any> extends Promise<Awaited<T>[]> {
+  items: Iterable<T>;
+  private promises;
+  get promise(): Promise<Awaited<T>[]>;
+  constructor(items?: Iterable<T>);
+  add(...args: (T | Promise<T>)[]): void;
+  map<U>(fn: (value: Awaited<T>, index: number) => U): PInstance<Promise<U>>;
+  filter(fn: (value: Awaited<T>, index: number) => boolean | Promise<boolean>): PInstance<Promise<T>>;
+  forEach(fn: (value: Awaited<T>, index: number) => void): Promise<void>;
+  reduce<U>(fn: (previousValue: U, currentValue: Awaited<T>, currentIndex: number, array: Awaited<T>[]) => U, initialValue: U): Promise<U>;
+  clear(): void;
+  then(fn?: () => PromiseLike<any>): Promise<any>;
+  catch(fn?: (err: unknown) => PromiseLike<any>): Promise<any>;
+  finally(fn?: () => void): Promise<Awaited<T>[]>;
+}
+```
+
+## Examples
+
+```typescript
+import { pChain } from 'js-utils-es/promise';
+
+const items = [1, 2, 3, 4, 5];
+
+await pChain(items)
+  .map(async i => await multiply(i, 3))
+  .filter(async i => await isEven(i))
+
+// Result: [6, 12]
+```

src/promise/pChain.spec.ts

@@ -0,0 +1,19 @@
+import { describe, expect, it } from 'vitest'
+import { pChain } from './pChain'
+
+const timeout = (ms: number) => new Promise(resolve => setTimeout(resolve, ms))
+
+describe('pChain', () => {
+  it('chain array map', async () => {
+    expect(
+      await pChain([1, 2, 3, 4, 5])
+        .map(async (i) => {
+          await timeout(10)
+          return i * i
+        })
+        .filter(i => i > 10)
+        .reduce((a, b) => a + b, 0),
+    )
+      .toEqual(41)
+  })
+})

src/promise/pChain.ts

@@ -0,0 +1,96 @@
+/**
+ * Internal marker for filtered items
+ */
+const VOID = Symbol('p-void')
+
+class PInstance<T = any> extends Promise<Awaited<T>[]> {
+  private promises = new Set<T | Promise<T>>()
+
+  get promise(): Promise<Awaited<T>[]> {
+    const items = [...Array.from(this.items), ...Array.from(this.promises)]
+
+    const batch = Promise.all(items)
+
+    return batch.then(l => l.filter((i: any) => i !== VOID))
+  }
+
+  constructor(public items: Iterable<T> = []) {
+    super(() => {})
+  }
+
+  add(...args: (T | Promise<T>)[]) {
+    args.forEach((i) => {
+      this.promises.add(i)
+    })
+  }
+
+  map<U>(fn: (value: Awaited<T>, index: number) => U): PInstance<Promise<U>> {
+    return new PInstance(
+      Array.from(this.items)
+        .map(async (i, idx) => {
+          const v = await i
+          if ((v as any) === VOID)
+            return VOID as unknown as U
+          return fn(v, idx)
+        }),
+    )
+  }
+
+  filter(fn: (value: Awaited<T>, index: number) => boolean | Promise<boolean>): PInstance<Promise<T>> {
+    return new PInstance(
+      Array.from(this.items)
+        .map(async (i, idx) => {
+          const v = await i
+          const r = await fn(v, idx)
+          if (!r)
+            return VOID as unknown as T
+          return v
+        }),
+    )
+  }
+
+  forEach(fn: (value: Awaited<T>, index: number) => void): Promise<void> {
+    return this.map(fn).then()
+  }
+
+  reduce<U>(fn: (previousValue: U, currentValue: Awaited<T>, currentIndex: number, array: Awaited<T>[]) => U, initialValue: U): Promise<U> {
+    return this.promise.then(array => array.reduce(fn, initialValue))
+  }
+
+  clear() {
+    this.promises.clear()
+  }
+
+  then(fn?: () => PromiseLike<any>) {
+    const p = this.promise
+    if (fn)
+      return p.then(fn)
+    else
+      return p
+  }
+
+  catch(fn?: (err: unknown) => PromiseLike<any>) {
+    return this.promise.catch(fn)
+  }
+
+  finally(fn?: () => void) {
+    return this.promise.finally(fn)
+  }
+}
+
+/**
+ * Utility for managing multiple promises.
+ *
+ * @example
+ * ```js
+ * const items = [1, 2, 3, 4, 5]
+ *
+ * await p(items)
+ *   .map(async i => await multiply(i, 3))
+ *   .filter(async i => await isEven(i))
+ * // [6, 12]
+ * ```
+ */
+export function pChain<T = any>(items?: Iterable<T>): PInstance<T> {
+  return new PInstance(items)
+}