AsyncGeneratorFunction() constructor
Baseline
Widely available
This feature is well established and works across many devices and browser versions. It’s been available across browsers since January 2020.
Warning: The arguments passed to this constructor are dynamically parsed and executed as JavaScript. APIs like this are known as injection sinks, and are potentially a vector for cross-site-scripting (XSS) attacks.
You can mitigate this risk by always passing TrustedScript objects instead of strings and enforcing trusted types.
See Security considerations in the Function() constructor reference for more information.
The AsyncGeneratorFunction() constructor creates AsyncGeneratorFunction objects.
Note that AsyncGeneratorFunction is not a global object. It could be obtained by evaluating the following code.
const AsyncGeneratorFunction = async function* () {}.constructor;
The AsyncGeneratorFunction() constructor is not intended to be used directly, and all caveats mentioned in the Function() description apply to AsyncGeneratorFunction().
Syntax
new AsyncGeneratorFunction(functionBody)
new AsyncGeneratorFunction(arg1, functionBody)
new AsyncGeneratorFunction(arg1, arg2, functionBody)
new AsyncGeneratorFunction(arg1, arg2, /* …, */ argN, functionBody)
AsyncGeneratorFunction(functionBody)
AsyncGeneratorFunction(arg1, functionBody)
AsyncGeneratorFunction(arg1, arg2, functionBody)
AsyncGeneratorFunction(arg1, arg2, /* …, */ argN, functionBody)
Note:
AsyncGeneratorFunction() can be called with or without new. Both create a new AsyncGeneratorFunction instance.
Parameters
See Function().
Examples
Note that these examples omit the use of trusted types for brevity. For code showing the recommended approach, see Using TrustedScript in eval().
Using the constructor
The following example uses the AsyncGeneratorFunction constructor to create an async generator function.
const AsyncGeneratorFunction = async function* () {}.constructor;
const createAsyncGenerator = new AsyncGeneratorFunction("a", "yield a * 2");
const asyncGen = createAsyncGenerator(10);
asyncGen.next().then((res) => console.log(res.value)); // 20
Specifications
| Specification |
|---|
| ECMAScript® 2026 Language Specification # sec-asyncgeneratorfunction-constructor |