feat: async generator guards

src/equals.ts

@@ -46,6 +46,7 @@ export const arraysEquals: Equals<any[]> = (arr1, arr2) => {
   if (!isArray(arr1) || !isArray(arr2)) {
     return false
   }
+
   if (arr1.length !== arr2.length) {
     return false
   }

src/guards.ts

@@ -54,6 +54,12 @@ export const isFunction = (n: unknown): n is Function => typeof n === 'function'
 export const isAsyncFunction = (n: unknown): n is Function =>
   isFunction(n) && n.constructor.name === 'AsyncFunction'
 
+export const isAsyncGenerator = <T>(value: any): value is AsyncGenerator<T> =>
+  value && typeof value[Symbol.asyncIterator] === 'function'
+
+export const isAsyncGeneratorFunction = (n: unknown): n is Function =>
+  isFunction(n) && n.constructor.name === 'AsyncGeneratorFunction'
+
 export const isSet = <T>(n: unknown): n is Set<T> => n instanceof Set
 
 export const isValidURL = (n: unknown): n is string => {

test/guards.test.ts

@@ -25,7 +25,9 @@ import {
   isRGBColorString,
   isHSLColorString,
   isLabColorString,
-  isLchColorString
+  isLchColorString,
+  isAsyncGenerator,
+  isAsyncGeneratorFunction
 } from '../src/guards'
 
 describe('Primitive Type Checkers', () => {
@@ -110,6 +112,49 @@ describe('Specialized Type and Functionality Checkers', () => {
     expect(isAsyncFunction(() => {})).toBe(false)
   })
 
+  it('isAsyncGenerator detects async generators', () => {
+    async function testAsync() {}
+    function testSync() {}
+
+    async function* testAsyncGenerator() {
+      yield 1
+      yield 2
+      yield 3
+    }
+    function* testSyncGenerator() {
+      yield 1
+      yield 2
+      yield 3
+    }
+    expect(isAsyncGenerator(testSync)).toBe(false)
+    expect(isAsyncGenerator(testAsync)).toBe(false)
+    expect(isAsyncGenerator(testAsyncGenerator())).toBe(true)
+    expect(isAsyncGenerator(testSyncGenerator())).toBe(false)
+    expect(isAsyncGenerator([1, 2, 3])).toBe(false)
+  })
+
+  it('isAsyncGeneratorFunction detects async generator functions', () => {
+    async function testAsync() {}
+    function testSync() {}
+    async function* testAsyncGenerator() {
+      yield 1
+      yield 2
+      yield 3
+    }
+
+    function* testSyncGenerator() {
+      yield 1
+      yield 2
+      yield 3
+    }
+
+    expect(isAsyncGenerator(testSync)).toBe(false)
+    expect(isAsyncGenerator(testAsync)).toBe(false)
+    expect(isAsyncGeneratorFunction(testAsyncGenerator)).toBe(true)
+    expect(isAsyncGeneratorFunction(testSyncGenerator)).toBe(false)
+    expect(isAsyncGeneratorFunction([1, 2, 3])).toBe(false)
+  })
+
   it('isSet checks for Set instances', () => {
     expect(isSet(new Set())).toBe(true)
     expect(isSet(new Map())).toBe(false)