Function then

then<HandlerInput, Output>(handler: Unary<HandlerInput, Output | PromiseLike<Output>>): (<PromiseInstance>(promise: PromiseInstance) => Promise<Output>)
Sets a promise then handler.

Example
```
const thenJson = then((response: Response) => response.json());

thenJson(fetch("/api")); // Parsed response
```
Returns
Curried function with handler set in context.
Type Parameters
- HandlerInput
- Output
Parameters
- handler: Unary<HandlerInput, Output | PromiseLike<Output>>
Returns (<PromiseInstance>(promise: PromiseInstance) => Promise<Output>)
- - <PromiseInstance>(promise: PromiseInstance): Promise<Output>
  - Type Parameters
    - PromiseInstance extends Promise<HandlerInput, PromiseInstance>
    Parameters
    - promise: PromiseInstance
    Returns Promise<Output>
- Defined in then.ts:16