fix: allow Iterable | AsyncIterable union input (#59)

achingbrain · web-flow · commit 80ec2ace4f64 · 2023-03-31T11:30:32.000+01:00
Compatiblity fix - where the input cannot be separated between
Iterable and AsyncIterable sources, update the types to return
async generators.

For best performance users should pass either Iterable or
AsyncIterable, not a union of both.
diff --git a/packages/it-all/src/index.ts b/packages/it-all/src/index.ts
@@ -6,8 +6,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Collects all values from an (async) iterable and returns them as an array
  */
 function all <T> (source: Iterable<T>): T[]
-function all <T> (source: AsyncIterable<T>): Promise<T[]>
-function all <T> (source: AsyncIterable<T> | Iterable<T>): Promise<T[]> | T[] {
+function all <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T[]>
+function all <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T[]> | T[] {
   if (isAsyncIterable(source)) {
     return (async () => {
       const arr = []
diff --git a/packages/it-batch/src/index.ts b/packages/it-batch/src/index.ts
@@ -7,8 +7,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * emits those things in fixed-sized batches
  */
 function batch <T> (source: Iterable<T>, size?: number): Generator<T[], void, undefined>
-function batch <T> (source: AsyncIterable<T> | Iterable<T>, size?: number): AsyncGenerator<T[], void, undefined>
-function batch <T> (source: AsyncIterable<T> | Iterable<T>, size: number = 1): Generator<T[], void, undefined> | AsyncGenerator<T[], void, undefined> {
+function batch <T> (source: Iterable<T> | AsyncIterable<T>, size?: number): AsyncGenerator<T[], void, undefined>
+function batch <T> (source: Iterable<T> | AsyncIterable<T>, size: number = 1): Generator<T[], void, undefined> | AsyncGenerator<T[], void, undefined> {
   size = Number(size)
 
   if (isAsyncIterable(source)) {
diff --git a/packages/it-batched-bytes/src/index.ts b/packages/it-batched-bytes/src/index.ts
@@ -35,7 +35,7 @@ export interface AsyncBatchedBytesOptions extends BatchedBytesOptions {
  * or the next event loop tick occurs, yield any bytes from the buffer.
  */
 function batchedBytes (source: Iterable<Uint8Array | Uint8ArrayList>, options?: BatchedBytesOptions): Iterable<Uint8Array>
-function batchedBytes (source: AsyncIterable<Uint8Array | Uint8ArrayList>, options?: AsyncBatchedBytesOptions): AsyncIterable<Uint8Array>
+function batchedBytes (source: Iterable<Uint8Array | Uint8ArrayList> | AsyncIterable<Uint8Array | Uint8ArrayList>, options?: AsyncBatchedBytesOptions): AsyncIterable<Uint8Array>
 function batchedBytes (source: Iterable<Uint8Array | Uint8ArrayList> | AsyncIterable<Uint8Array | Uint8ArrayList>, options: AsyncBatchedBytesOptions = {}): AsyncIterable<Uint8Array> | Iterable<Uint8Array> {
   if (isAsyncIterable(source)) {
     return (async function * () {
diff --git a/packages/it-drain/src/index.ts b/packages/it-drain/src/index.ts
@@ -7,8 +7,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * anything
  */
 function drain (source: Iterable<unknown>): void
-function drain (source: AsyncIterable<unknown>): Promise<void>
-function drain (source: AsyncIterable<unknown> | Iterable<unknown>): Promise<void> | void {
+function drain (source: Iterable<unknown> | AsyncIterable<unknown>): Promise<void>
+function drain (source: Iterable<unknown> | AsyncIterable<unknown>): Promise<void> | void {
   if (isAsyncIterable(source)) {
     return (async () => {
       for await (const _ of source) { } // eslint-disable-line no-unused-vars,no-empty,@typescript-eslint/no-unused-vars
diff --git a/packages/it-first/src/index.ts b/packages/it-first/src/index.ts
@@ -7,8 +7,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * case returns `undefined`
  */
 function first <T> (source: Iterable<T>): T | undefined
-function first <T> (source: AsyncIterable<T>): Promise<T | undefined>
-function first <T> (source: AsyncIterable<T> | Iterable<T>): Promise<T | undefined> | T | undefined {
+function first <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T | undefined>
+function first <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T | undefined> | T | undefined {
   if (isAsyncIterable(source)) {
     return (async () => {
       for await (const entry of source) { // eslint-disable-line no-unreachable-loop
diff --git a/packages/it-flat-batch/src/index.ts b/packages/it-flat-batch/src/index.ts
@@ -7,8 +7,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * returns an async iterable that emits those things in fixed-size batches
  */
 function batch <T> (source: Iterable<T[]>, batchSize?: number): Generator<T[], void, undefined>
-function batch <T> (source: AsyncIterable<T[]>, batchSize?: number): AsyncGenerator<T[], void, undefined>
-function batch <T> (source: AsyncIterable<T[]> | Iterable<T[]>, batchSize: number = 1): AsyncGenerator<T[], void, undefined> | Generator<T[], void, undefined> {
+function batch <T> (source: Iterable<T[]> | AsyncIterable<T[]>, batchSize?: number): AsyncGenerator<T[], void, undefined>
+function batch <T> (source: Iterable<T[]> | AsyncIterable<T[]>, batchSize: number = 1): AsyncGenerator<T[], void, undefined> | Generator<T[], void, undefined> {
   let size = parseInt(`${batchSize}`)
 
   if (isNaN(size) || size < 1) {
diff --git a/packages/it-foreach/src/index.ts b/packages/it-foreach/src/index.ts
@@ -9,8 +9,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  */
 function forEach <T> (source: Iterable<T>, fn: (thing: T) => Promise<void>): AsyncGenerator<T, void, undefined>
 function forEach <T> (source: Iterable<T>, fn: (thing: T) => void): Generator<T, void, undefined>
-function forEach <T> (source: AsyncIterable<T>, fn: (thing: T) => void | Promise<void>): AsyncGenerator<T, void, undefined>
-function forEach <T> (source: AsyncIterable<T> | Iterable<T>, fn: (thing: T) => void | Promise<void>): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
+function forEach <T> (source: Iterable<T> | AsyncIterable<T>, fn: (thing: T) => void | Promise<void>): AsyncGenerator<T, void, undefined>
+function forEach <T> (source: Iterable<T> | AsyncIterable<T>, fn: (thing: T) => void | Promise<void>): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
   if (isAsyncIterable(source)) {
     return (async function * () {
       for await (const thing of source) {
diff --git a/packages/it-last/src/index.ts b/packages/it-last/src/index.ts
@@ -7,8 +7,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * return `undefined`
  */
 function last <T> (source: Iterable<T>): T | undefined
-function last <T> (source: AsyncIterable<T>): Promise<T | undefined>
-function last <T> (source: AsyncIterable<T> | Iterable<T>): Promise<T | undefined> | T | undefined {
+function last <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T | undefined>
+function last <T> (source: Iterable<T> | AsyncIterable<T>): Promise<T | undefined> | T | undefined {
   if (isAsyncIterable(source)) {
     return (async () => {
       let res
diff --git a/packages/it-length/src/index.ts b/packages/it-length/src/index.ts
@@ -6,8 +6,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Consumes the passed iterator and returns the number of items it contained
  */
 function length (source: Iterable<unknown>): number
-function length (source: AsyncIterable<unknown>): Promise<number>
-function length (source: AsyncIterable<unknown> | Iterable<unknown>): Promise<number> | number {
+function length (source: Iterable<unknown> | AsyncIterable<unknown>): Promise<number>
+function length (source: Iterable<unknown> | AsyncIterable<unknown>): Promise<number> | number {
   if (isAsyncIterable(source)) {
     return (async () => {
       let count = 0
diff --git a/packages/it-map/src/index.ts b/packages/it-map/src/index.ts
@@ -10,7 +10,7 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  */
 function map <I, O> (source: Iterable<I>, func: (val: I) => Promise<O>): AsyncGenerator<O, void, undefined>
 function map <I, O> (source: Iterable<I>, func: (val: I) => O): Generator<O, void, undefined>
-function map <I, O> (source: AsyncIterable<I>, func: (val: I) => O | Promise<O>): AsyncGenerator<O, void, undefined>
+function map <I, O> (source: AsyncIterable<I> | Iterable<I>, func: (val: I) => O | Promise<O>): AsyncGenerator<O, void, undefined>
 function map <I, O> (source: AsyncIterable<I> | Iterable<I>, func: (val: I) => O | Promise<O>): AsyncGenerator<O, void, undefined> | Generator<O, void, undefined> {
   if (isAsyncIterable(source)) {
     return (async function * () {
diff --git a/packages/it-map/test/index.spec.ts b/packages/it-map/test/index.spec.ts
@@ -1,13 +1,21 @@
 import { expect } from 'aegir/chai'
 import map from '../src/index.js'
 
+async function * asyncGenerator (): AsyncGenerator<number> {
+  yield 1
+}
+
+function * generator (): Generator<number> {
+  yield 1
+}
+
+async function * source (): Generator<number> | AsyncGenerator<number> {
+  yield 1
+}
+
 describe('it-map', () => {
   it('should map an async iterator', async () => {
-    const iter = async function * (): AsyncGenerator<number> {
-      yield 1
-    }
-
-    const gen = map(iter(), (val) => val + 1)
+    const gen = map(asyncGenerator(), (val) => val + 1)
     expect(gen[Symbol.asyncIterator]).to.be.ok()
 
     for await (const result of gen) {
@@ -16,11 +24,7 @@ describe('it-map', () => {
   })
 
   it('should map an async iterator to a promise', async () => {
-    const iter = async function * (): AsyncGenerator<number, void, unknown> {
-      yield 1
-    }
-
-    const gen = map(iter(), async (val) => val + 1)
+    const gen = map(asyncGenerator(), async (val) => val + 1)
     expect(gen[Symbol.asyncIterator]).to.be.ok()
 
     for await (const result of gen) {
@@ -29,11 +33,7 @@ describe('it-map', () => {
   })
 
   it('should map an iterator', () => {
-    const iter = function * (): Generator<number> {
-      yield 1
-    }
-
-    const gen = map(iter(), (val) => val + 1)
+    const gen = map(generator(), (val) => val + 1)
     expect(gen[Symbol.iterator]).to.be.ok()
 
     for (const result of gen) {
@@ -42,11 +42,16 @@ describe('it-map', () => {
   })
 
   it('should map an iterator to a promise', async () => {
-    const iter = function * (): Generator<number> {
-      yield 1
+    const gen = map(generator(), async (val) => val + 1)
+    expect(gen[Symbol.asyncIterator]).to.be.ok()
+
+    for await (const result of gen) {
+      expect(result).to.equal(2)
     }
+  })
 
-    const gen = map(iter(), async (val) => val + 1)
+  it('should map a source', async () => {
+    const gen = map(source(), (val) => val + 1)
     expect(gen[Symbol.asyncIterator]).to.be.ok()
 
     for await (const result of gen) {
diff --git a/packages/it-reduce/src/index.ts b/packages/it-reduce/src/index.ts
@@ -6,8 +6,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Reduces the values yielded by an (async) iterable
  */
 function reduce <T, V> (source: Iterable<T>, func: (acc: V, curr: T) => V, init: V): V
-function reduce <T, V> (source: AsyncIterable<T>, func: (acc: V, curr: T) => V, init: V): Promise<V>
-function reduce <T, V> (source: AsyncIterable<T> | Iterable<T>, func: (acc: V, curr: T) => V, init: V): Promise<V> | V {
+function reduce <T, V> (source: Iterable<T> | AsyncIterable<T>, func: (acc: V, curr: T) => V, init: V): Promise<V>
+function reduce <T, V> (source: Iterable<T> | AsyncIterable<T>, func: (acc: V, curr: T) => V, init: V): Promise<V> | V {
   if (isAsyncIterable(source)) {
     return (async function () {
       for await (const val of source) {
diff --git a/packages/it-skip/src/index.ts b/packages/it-skip/src/index.ts
@@ -6,8 +6,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Skip items from an iterable
  */
 function skip <T> (source: Iterable<T>, offset: number): Generator<T, void, undefined>
-function skip <T> (source: AsyncIterable<T>, offset: number): AsyncGenerator<T, void, undefined>
-function skip <T> (source: AsyncIterable<T> | Iterable<T>, offset: number): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
+function skip <T> (source: Iterable<T> | AsyncIterable<T>, offset: number): AsyncGenerator<T, void, undefined>
+function skip <T> (source: Iterable<T> | AsyncIterable<T>, offset: number): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
   if (isAsyncIterable(source)) {
     return (async function * () {
       for await (const entry of source) {
diff --git a/packages/it-sort/src/index.ts b/packages/it-sort/src/index.ts
@@ -13,8 +13,8 @@ export interface CompareFunction<T> {
  * using the passed function and yields them
  */
 function sort <T> (source: Iterable<T>, sorter: CompareFunction<T>): Generator<T, void, undefined>
-function sort <T> (source: AsyncIterable<T>, sorter: CompareFunction<T>): AsyncGenerator<T, void, undefined>
-function sort <T> (source: AsyncIterable<T> | Iterable<T>, sorter: CompareFunction<T>): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
+function sort <T> (source: Iterable<T> | AsyncIterable<T>, sorter: CompareFunction<T>): AsyncGenerator<T, void, undefined>
+function sort <T> (source: Iterable<T> | AsyncIterable<T>, sorter: CompareFunction<T>): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
   if (isAsyncIterable(source)) {
     return (async function * () {
       const arr = await all(source)
diff --git a/packages/it-split/src/index.ts b/packages/it-split/src/index.ts
@@ -12,8 +12,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Splits Uint8Arrays emitted by an (async) iterable by a delimiter
  */
 function split (source: Iterable<Uint8Array>, options?: SplitOptions): Generator<Uint8Array, void, undefined>
-function split (source: AsyncIterable<Uint8Array>, options?: SplitOptions): AsyncGenerator<Uint8Array, void, undefined>
-function split (source: AsyncIterable<Uint8Array> | Iterable<Uint8Array>, options: SplitOptions = {}): AsyncGenerator<Uint8Array, void, undefined> | Generator<Uint8Array, void, undefined> {
+function split (source: Iterable<Uint8Array> | AsyncIterable<Uint8Array>, options?: SplitOptions): AsyncGenerator<Uint8Array, void, undefined>
+function split (source: Iterable<Uint8Array> | AsyncIterable<Uint8Array>, options: SplitOptions = {}): AsyncGenerator<Uint8Array, void, undefined> | Generator<Uint8Array, void, undefined> {
   const bl = new Uint8ArrayList()
   const delimiter = options.delimiter ?? new TextEncoder().encode('\n')
 
diff --git a/packages/it-take/src/index.ts b/packages/it-take/src/index.ts
@@ -6,8 +6,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * Stop iteration after n items have been received
  */
 function take <T> (source: Iterable<T>, limit: number): Generator<T, void, undefined>
-function take <T> (source: AsyncIterable<T>, limit: number): AsyncGenerator<T, void, undefined>
-function take <T> (source: AsyncIterable<T> | Iterable<T>, limit: number): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
+function take <T> (source: Iterable<T> | AsyncIterable<T>, limit: number): AsyncGenerator<T, void, undefined>
+function take <T> (source: Iterable<T> | AsyncIterable<T>, limit: number): AsyncGenerator<T, void, undefined> | Generator<T, void, undefined> {
   if (isAsyncIterable(source)) {
     return (async function * () {
       let items = 0
diff --git a/packages/it-to-buffer/src/index.ts b/packages/it-to-buffer/src/index.ts
@@ -9,8 +9,8 @@ function isAsyncIterable <T> (thing: any): thing is AsyncIterable<T> {
  * into one buffer
  */
 function toBuffer (source: Iterable<Uint8Array>): Uint8Array
-function toBuffer (source: AsyncIterable<Uint8Array>): Promise<Uint8Array>
-function toBuffer (source: AsyncIterable<Uint8Array> | Iterable<Uint8Array>): Promise<Uint8Array> | Uint8Array {
+function toBuffer (source: Iterable<Uint8Array> | AsyncIterable<Uint8Array>): Promise<Uint8Array>
+function toBuffer (source: Iterable<Uint8Array> | AsyncIterable<Uint8Array>): Promise<Uint8Array> | Uint8Array {
   if (isAsyncIterable(source)) {
     return (async () => {
       let buffer = new Uint8Array(0)
