From 2f25a5037c21a34ea1dadca8b61781f79c3cbe41 Mon Sep 17 00:00:00 2001
From: Vadim Demedes <vadimdemedes@hey.com>
Date: Mon, 24 Apr 2023 12:55:12 +0300
Subject: [PATCH] Add escapes for entering/exiting the alternative screen (#33)

---
 index.d.ts      | 10 ++++++++++
 index.js        |  3 +++
 index.test-d.ts |  2 ++
 readme.md       |  8 ++++++++
 4 files changed, 23 insertions(+)

diff --git a/index.d.ts b/index.d.ts
index c7f7ef0..34d9bb5 100644
--- a/index.d.ts
+++ b/index.d.ts
@@ -199,6 +199,16 @@ declare const ansiEscapes: {
 	*/
 	clearTerminal: string;
 
+	/**
+	Enter the [alternative screen](https://terminalguide.namepad.de/mode/p47/).
+	*/
+	enterAlternativeScreen: string;
+
+	/**
+	Exit the [alternative screen](https://terminalguide.namepad.de/mode/p47/), assuming `enterAlternativeScreen` was called before.
+	*/
+	exitAlternativeScreen: string;
+
 	/**
 	Output a beeping sound.
 	*/
diff --git a/index.js b/index.js
index 9307dfc..1495e31 100644
--- a/index.js
+++ b/index.js
@@ -97,6 +97,9 @@ ansiEscapes.clearTerminal = isWindows
 	// More info: https://www.real-world-systems.com/docs/ANSIcode.html
 	: `${ansiEscapes.eraseScreen}${ESC}3J${ESC}H`;
 
+ansiEscapes.enterAlternativeScreen = ESC + '?1049h';
+ansiEscapes.exitAlternativeScreen = ESC + '?1049l';
+
 ansiEscapes.beep = BEL;
 
 ansiEscapes.link = (text, url) => [
diff --git a/index.test-d.ts b/index.test-d.ts
index f5e6ee1..a16be90 100644
--- a/index.test-d.ts
+++ b/index.test-d.ts
@@ -33,6 +33,8 @@ expectType<string>(ansiEscapes.scrollUp);
 expectType<string>(ansiEscapes.scrollDown);
 expectType<string>(ansiEscapes.clearScreen);
 expectType<string>(ansiEscapes.clearTerminal);
+expectType<string>(ansiEscapes.enterAlternativeScreen);
+expectType<string>(ansiEscapes.exitAlternativeScreen);
 expectType<string>(ansiEscapes.beep);
 expectType<string>(ansiEscapes.link('foo', 'https://foo.bar'));
 expectType<string>(ansiEscapes.image(Buffer.from('1')));
diff --git a/readme.md b/readme.md
index 30f73e7..c684ee4 100644
--- a/readme.md
+++ b/readme.md
@@ -134,6 +134,14 @@ Clear the terminal screen. (Viewport)
 
 Clear the whole terminal, including scrollback buffer. (Not just the visible part of it)
 
+### enterAlternativeScreen
+
+Enter the [alternative screen](https://terminalguide.namepad.de/mode/p47/).
+
+### exitAlternativeScreen
+
+Exit the [alternative screen](https://terminalguide.namepad.de/mode/p47/), assuming `enterAlternativeScreen` was called before.
+
 ### beep
 
 Output a beeping sound.