Add truncationCharacter option (#19)

Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>
sindresorhus · Oct 9, 2021 · 23b40dc · 23b40dc
1 parent 42f602d
commit 23b40dc
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Showing 4 changed files with 64 additions and 16 deletions.
diff --git a/index.d.ts b/index.d.ts
@@ -50,6 +50,26 @@ export interface Options {
 	````
 	*/
 	readonly preferTruncationOnSpace?: boolean;
+
+	/**
+	The character to use at the breaking point.
+
+	@default '…'
+
+	@example
+	```
+	import cliTruncate from 'cli-truncate';
+
+	cliTruncate('unicorns', 5, {position: 'end'});
+	//=> 'unic…'
+
+	cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: '.'});
+	//=> 'unic.'
+
+	cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: ''});
+	//=> 'unico'
+	*/
+	readonly truncationCharacter?: string;
 }
 
 /**

diff --git a/index.js b/index.js
@@ -23,12 +23,12 @@ export default function cliTruncate(text, columns, options) {
 	options = {
 		position: 'end',
 		preferTruncationOnSpace: false,
+		truncationCharacter: '…',
 		...options,
 	};
 
 	const {position, space, preferTruncationOnSpace} = options;
-	let ellipsis = '…';
-	let ellipsisWidth = 1;
+	let {truncationCharacter} = options;
 
 	if (typeof text !== 'string') {
 		throw new TypeError(`Expected \`input\` to be a string, got ${typeof text}`);
@@ -43,7 +43,7 @@ export default function cliTruncate(text, columns, options) {
 	}
 
 	if (columns === 1) {
-		return ellipsis;
+		return truncationCharacter;
 	}
 
 	const length = stringWidth(text);
@@ -55,50 +55,47 @@ export default function cliTruncate(text, columns, options) {
 	if (position === 'start') {
 		if (preferTruncationOnSpace) {
 			const nearestSpace = getIndexOfNearestSpace(text, length - columns + 1, true);
-			return ellipsis + sliceAnsi(text, nearestSpace, length).trim();
+			return truncationCharacter + sliceAnsi(text, nearestSpace, length).trim();
 		}
 
 		if (space === true) {
-			ellipsis += ' ';
-			ellipsisWidth = 2;
+			truncationCharacter += ' ';
 		}
 
-		return ellipsis + sliceAnsi(text, length - columns + ellipsisWidth, length);
+		return truncationCharacter + sliceAnsi(text, length - columns + stringWidth(truncationCharacter), length);
 	}
 
 	if (position === 'middle') {
 		if (space === true) {
-			ellipsis = ` ${ellipsis} `;
-			ellipsisWidth = 3;
+			truncationCharacter = ` ${truncationCharacter} `;
 		}
 
 		const half = Math.floor(columns / 2);
 
 		if (preferTruncationOnSpace) {
 			const spaceNearFirstBreakPoint = getIndexOfNearestSpace(text, half);
 			const spaceNearSecondBreakPoint = getIndexOfNearestSpace(text, length - (columns - half) + 1, true);
-			return sliceAnsi(text, 0, spaceNearFirstBreakPoint) + ellipsis + sliceAnsi(text, spaceNearSecondBreakPoint, length).trim();
+			return sliceAnsi(text, 0, spaceNearFirstBreakPoint) + truncationCharacter + sliceAnsi(text, spaceNearSecondBreakPoint, length).trim();
 		}
 
 		return (
 			sliceAnsi(text, 0, half)
-				+ ellipsis
-				+ sliceAnsi(text, length - (columns - half) + ellipsisWidth, length)
+				+ truncationCharacter
+				+ sliceAnsi(text, length - (columns - half) + stringWidth(truncationCharacter), length)
 		);
 	}
 
 	if (position === 'end') {
 		if (preferTruncationOnSpace) {
 			const nearestSpace = getIndexOfNearestSpace(text, columns - 1);
-			return sliceAnsi(text, 0, nearestSpace) + ellipsis;
+			return sliceAnsi(text, 0, nearestSpace) + truncationCharacter;
 		}
 
 		if (space === true) {
-			ellipsis = ` ${ellipsis}`;
-			ellipsisWidth = 2;
+			truncationCharacter = ` ${truncationCharacter}`;
 		}
 
-		return sliceAnsi(text, 0, columns - ellipsisWidth) + ellipsis;
+		return sliceAnsi(text, 0, columns - stringWidth(truncationCharacter)) + truncationCharacter;
 	}
 
 	throw new Error(`Expected \`options.position\` to be either \`start\`, \`middle\` or \`end\`, got ${position}`);

diff --git a/readme.md b/readme.md
@@ -124,6 +124,26 @@ cliTruncate('unicorns rainbow dragons', 6, {position: 'middle', preferTruncation
 //=> 'uni…ns'
 ```
 
+##### truncationCharacter
+
+Type: `string`\
+Default: `…`
+
+The character to use at the breaking point.
+
+```js
+import cliTruncate from 'cli-truncate';
+
+cliTruncate('unicorns', 5, {position: 'end'});
+//=> 'unic…'
+
+cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: '.'});
+//=> 'unic.'
+
+cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: ''});
+//=> 'unico'
+```
+
 ## Related
 
 - [wrap-ansi](https://github.com/chalk/wrap-ansi) - Wordwrap a string with ANSI escape codes

diff --git a/test.js b/test.js
@@ -43,3 +43,14 @@ test('preferTruncationOnSpace option', t => {
 	t.is(cliTruncate('unicorns rainbow dragons', 6, {position: 'middle', preferTruncationOnSpace: true}), 'uni…ns');
 	t.is(cliTruncate('unicorns partying with dragons', 20, {position: 'middle', preferTruncationOnSpace: true}), 'unicorns…dragons');
 });
+
+test('truncationCharacter option', t => {
+	t.is(cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: '.'}), 'unic.');
+	t.is(cliTruncate('unicorns', 5, {position: 'start', truncationCharacter: '.'}), '.orns');
+	t.is(cliTruncate('unicorns', 5, {position: 'middle', truncationCharacter: '.'}), 'un.ns');
+	t.is(cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: '.', space: true}), 'uni .');
+	t.is(cliTruncate('unicorns', 5, {position: 'end', truncationCharacter: ' .'}), 'uni .');
+	t.is(cliTruncate('unicorns partying with dragons', 20, {position: 'middle', truncationCharacter: '.', preferTruncationOnSpace: true}), 'unicorns.dragons');
+	t.is(cliTruncate('안녕하세요', 4, {position: 'start', space: true, truncationCharacter: '.'}), '. 요', 'wide char');
+	t.is(cliTruncate('\u001B[31municornsareawesome\u001B[39m', 10, {position: 'middle', space: true, truncationCharacter: '.'}), '\u001B[31munico\u001B[39m . \u001B[31mme\u001B[39m');
+});