Awesome
ink-testing-library 
Utilities for testing Ink apps
Install
$ npm install --save-dev ink-testing-library
Usage
import React from 'react';
import {Text} from 'ink';
import {render} from 'ink-testing-library';
const Counter = ({count}) => <Text>Count: {count}</Text>;
const {lastFrame, rerender} = render(<Counter count={0}/>);
lastFrame() === 'Count: 0'; //=> true
rerender(<Counter count={1}/>);
lastFrame() === 'Count: 1'; //=> true
API
render(tree)
tree
Type: ReactElement
React component to render.
render(<MyApp/>);
This function returns an object, which contains the following methods and properties.
lastFrame()
Type: function
Shortcut to stdout.lastFrame.
frames
Type: array
Shortcut to stdout.frames.
rerender(tree)
Type: function
tree
Type: ReactElement
Rerender root component with different props or replace with another component.
const {rerender} = render(<OldApp/>);
rerender(<NewApp/>);
unmount()
Type: function
Unmount current component.
const {unmount} = render(<Test/>);
unmount();
stdin
Type: object
write()
Type: function
Write data to current component's stdin stream.
import {useInput, Text} from 'ink';
const Test = () => {
useInput(input => {
console.log(input);
//=> 'hello'
});
return …;
};
const {stdin} = render(<Test/>);
stdin.write('hello');
stdout
Type: object
lastFrame()
Type: function
Return the last rendered frame (output) from stdout stream.
const Test = () => <Text>Hello</Text>;
const {stdout} = render(<Test/>);
stdout.lastFrame(); //=> 'Hello'
frames
Type: array
Array of all rendered frames, where the last frame is also the last item in that array.
const Counter = ({count}) => <Text>Count: {count}</Text>;
const {stdout, rerender} = render(<Counter count={0}/>);
rerender(<Counter count={1}/>);
console.log(stdout.frames); //=> ['Count: 0', 'Count: 1']
stderr
Type: object
lastFrame()
Type: function
Same as lastFrame in stdout, but for stderr stream.
frames
Type: array