Allow border to be optional.

index.d.ts

@@ -1,5 +1,12 @@
 import {LiteralUnion} from 'type-fest';
-import {BoxStyle, Boxes} from 'cli-boxes';
+import {BoxStyle, Boxes as CLIBoxes} from 'cli-boxes';
+
+/**
+All box styles.
+*/
+interface Boxes extends CLIBoxes {
+	readonly none: BoxStyle;
+}
 
 /**
 Characters used for custom border.

index.js

@@ -56,6 +56,14 @@ const getBorderChars = borderStyle => {
 
 	let characters;
 
+	// Create empty border style
+	if (borderStyle === 'none') {
+		borderStyle = {};
+		for (const side of sides) {
+			borderStyle[side] = '';
+		}
+	}
+
 	if (typeof borderStyle === 'string') {
 		characters = cliBoxes[borderStyle];
 
@@ -76,7 +84,7 @@ const getBorderChars = borderStyle => {
 		}
 
 		for (const side of sides) {
-			if (!borderStyle[side] || typeof borderStyle[side] !== 'string') {
+			if (borderStyle[side] === null || typeof borderStyle[side] !== 'string') {
 				throw new TypeError(`Invalid border style: ${side}`);
 			}
 		}

readme.md

@@ -116,6 +116,12 @@ Values:
 ↘↓↓↓↙
 →foo←
 ↗↑↑↑↖
+```
+- `'none'`
+```
+
+foo
+
 ```
 
 Style of the box border.

tests/border-option.js

@@ -105,6 +105,14 @@ test('border style (round)', t => {
 	t.snapshot(box);
 });
 
+test('border style (none)', t => {
+	const box = boxen('foo', {
+		borderStyle: 'none',
+	});
+
+	t.snapshot(box);
+});
+
 test('border style (custom ascii style)', t => {
 	const box = boxen('foo', {
 		borderStyle: {

tests/snapshots/tests/border-option.js.md

@@ -100,6 +100,14 @@ Generated by [AVA](https://avajs.dev).
     │foo│␊
     ╰───╯`
 
+## border style (none)
+
+> Snapshot 1
+
+    `␊
+    foo␊
+    `
+
 ## border style (custom ascii style)
 
 > Snapshot 1