add useKeypress hook

examples/usekeypress/index.js

@@ -0,0 +1,2 @@
+'use strict';
+require('import-jsx')('./usekeypress');

examples/usekeypress/usekeypress.js

@@ -0,0 +1,42 @@
+'use strict';
+const {useState} = require('react');
+const React = require('react');
+const {render, useKeypress, Box} = require('../..');
+
+const {exit} = process;
+
+const Robot = () => {
+	const [x, setX] = useState(1);
+	const [y, setY] = useState(1);
+
+	useKeypress(key => {
+		switch (key) {
+			case 'h':
+				setX(Math.max(1, x - 1));
+				break;
+			case 'l':
+				setX(Math.min(80, x + 1));
+				break;
+			case 'j':
+				setY(Math.min(40, y + 1));
+				break;
+			case 'k':
+				setY(Math.max(1, y - 1));
+				break;
+			case 'q':
+				exit();
+				break;
+			default:
+				break;
+		}
+	});
+
+	return (
+		<Box flexDirection="column">
+			<Box>Use h, j, k, and l to move the face. q to exit</Box>
+			<Box marginTop={y} marginLeft={x}>^_^</Box>
+		</Box>
+	);
+};
+
+render(<Robot/>);

index.d.ts

@@ -1,4 +1,5 @@
 import * as React from "react";
+import { Key } from 'readline';
 
 export interface RenderOptions {
 	/**
@@ -44,6 +45,14 @@ export type Instance = {
 
 export type Unmount = () => void;
 
+/**
+ * Hook that calls keyPressHandler callback with whatever key has been pressed.
+ * See key to handle modifiers correctly.
+ */
+export function useKeypress(
+	keyPressHandler: (str?: string, key?: Key) => void
+): void;
+
 /**
  * Mount a component and render the output.
  */

package.json

@@ -118,7 +118,10 @@
 		],
 		"overrides": [
 			{
-				"files": "src/components/*.js",
+				"files": [
+					"src/components/*.js",
+					"src/hooks/*.js"
+				],
 				"rules": {
 					"unicorn/filename-case": "off",
 					"react/require-default-props": "warning"

src/hooks/useKeypress.js

@@ -0,0 +1,15 @@
+import {useEffect, useContext} from 'react';
+import {StdinContext} from '..';
+
+export default keypressHandler => {
+	const {stdin, setRawMode} = useContext(StdinContext);
+
+	useEffect(() => {
+		setRawMode(true);
+		stdin.on('keypress', keypressHandler);
+		return () => {
+			stdin.off('keypress', keypressHandler);
+			setRawMode(false);
+		};
+	}, [stdin, setRawMode, keypressHandler]);
+};

src/index.js

@@ -6,3 +6,4 @@ export {default as AppContext} from './components/AppContext';
 export {default as StdinContext} from './components/StdinContext';
 export {default as StdoutContext} from './components/StdoutContext';
 export {default as Static} from './components/Static';
+export {default as useKeypress} from './hooks/useKeypress';

test/exit.js

@@ -47,6 +47,48 @@ test('exit with thrown error', async t => {
 	t.true(output.includes('errored'));
 });
 
+test.cb('handles keypresses', t => {
+	const term = spawn('node', ['./fixtures/run', './handles-keypresses'], {
+		name: 'xterm',
+		cols: 100,
+		cwd: __dirname,
+		env: process.env
+	});
+
+	let output = '';
+
+	term.on('data', data => {
+		output += data;
+	});
+
+	let isExited = false;
+
+	term.on('exit', code => {
+		isExited = true;
+
+		if (code === 0) {
+			t.true(output.includes('exited'));
+			t.pass();
+			t.end();
+			return;
+		}
+
+		t.fail();
+		t.end();
+	});
+
+	setTimeout(() => {
+		t.false(isExited);
+		'abcdefghijklmnopqrstuvwxyz'.split('').forEach(key => term.write(key));
+	}, 100);
+
+	setTimeout(() => {
+		term.kill();
+		t.fail();
+		t.end();
+	}, 5000);
+});
+
 test.cb('don\'t exit while raw mode is active', t => {
 	const term = spawn('node', ['./fixtures/run', './exit-double-raw-mode'], {
 		name: 'xterm-color',

test/fixtures/handles-keypresses.js

@@ -0,0 +1,22 @@
+'use strict';
+const React = require('react');
+const {render, useKeypress} = require('../..');
+
+const input = new Set('abcdefghijklmnopqrstuvwxyz'.split(''));
+
+const KeypressTest = () => {
+	useKeypress(str => {
+		input.delete(str);
+		if (input.size === 0) {
+			app.unmount();
+		}
+	});
+	return null;
+};
+
+const app = render(<KeypressTest/>);
+
+(async () => {
+	await app.waitUntilExit();
+	console.log('exited');
+})();