cli-truncate - npm Package Compare versions

Comparing version 5.0.0 to 5.1.0

index.d.ts

@@ -96,4 +96,6 @@ export type Options = {
 cliTruncate('\u001B[31municorn\u001B[39m', 4);
-//=> '\u001B[31muni\u001B[39m…'
+//=> '\u001B[31muni…\u001B[39m'
 
+// Note: When truncating styled text (ANSI escapes), the truncation character inherits the style at the breaking point for `position: 'start'` and `position: 'end'`. This does not apply to `position: 'middle'`.
+
 // Truncate Unicode surrogate pairs
@@ -100,0 +102,0 @@ cliTruncate('uni\uD83C\uDE00corn', 5);

index.js

@@ -52,17 +52,84 @@ import sliceAnsi from 'slice-ansi';
 
+	// ANSI escape sequence constants
+	const ANSI = {
+		ESC: 27,
+		LEFT_BRACKET: 91,
+		LETTER_M: 109,
+	};
+
+	const isSgrParameter = code => (code >= 48 && code <= 57) || code === 59; // 0-9 or ;
+
+	function leadingSgrSpanEndIndex(string) {
+		let index = 0;
+		while (index + 2 < string.length && string.codePointAt(index) === ANSI.ESC && string.codePointAt(index + 1) === ANSI.LEFT_BRACKET) {
+			let j = index + 2;
+			while (j < string.length && isSgrParameter(string.codePointAt(j))) {
+				j++;
+			}
+
+			if (j < string.length && string.codePointAt(j) === ANSI.LETTER_M) {
+				index = j + 1;
+				continue;
+			}
+
+			break;
+		}
+
+		return index;
+	}
+
+	function trailingSgrSpanStartIndex(string) {
+		let start = string.length;
+		while (start > 1 && string.codePointAt(start - 1) === ANSI.LETTER_M) {
+			let j = start - 2;
+			while (j >= 0 && isSgrParameter(string.codePointAt(j))) {
+				j--;
+			}
+
+			if (j >= 1 && string.codePointAt(j - 1) === ANSI.ESC && string.codePointAt(j) === ANSI.LEFT_BRACKET) {
+				start = j - 1;
+				continue;
+			}
+
+			break;
+		}
+
+		return start;
+	}
+
+	function appendWithInheritedStyleFromEnd(visible, suffix) {
+		const start = trailingSgrSpanStartIndex(visible);
+		if (start === visible.length) {
+			return visible + suffix;
+		}
+
+		return visible.slice(0, start) + suffix + visible.slice(start);
+	}
+
+	function prependWithInheritedStyleFromStart(prefix, visible) {
+		const end = leadingSgrSpanEndIndex(visible);
+		if (end === 0) {
+			return prefix + visible;
+		}
+
+		return visible.slice(0, end) + prefix + visible.slice(end);
+	}
+
 	if (position === 'start') {
 		if (preferTruncationOnSpace) {
 			const nearestSpace = getIndexOfNearestSpace(text, length - columns + 1, true);
-			return truncationCharacter + sliceAnsi(text, nearestSpace, length).trim();
+			const right = sliceAnsi(text, nearestSpace, length).trim();
+			return prependWithInheritedStyleFromStart(truncationCharacter, right);
 		}
 
-		if (space === true) {
+		if (space) {
 			truncationCharacter += ' ';
 		}
 
-		return truncationCharacter + sliceAnsi(text, length - columns + stringWidth(truncationCharacter), length);
+		const right = sliceAnsi(text, length - columns + stringWidth(truncationCharacter), length);
+		return prependWithInheritedStyleFromStart(truncationCharacter, right);
 	}
 
 	if (position === 'middle') {
-		if (space === true) {
+		if (space) {
 			truncationCharacter = ` ${truncationCharacter} `;
@@ -89,10 +156,12 @@ }
 			const nearestSpace = getIndexOfNearestSpace(text, columns - 1);
-			return sliceAnsi(text, 0, nearestSpace) + truncationCharacter;
+			const left = sliceAnsi(text, 0, nearestSpace);
+			return appendWithInheritedStyleFromEnd(left, truncationCharacter);
 		}
 
-		if (space === true) {
+		if (space) {
 			truncationCharacter = ` ${truncationCharacter}`;
 		}
 
-		return sliceAnsi(text, 0, columns - stringWidth(truncationCharacter)) + truncationCharacter;
+		const left = sliceAnsi(text, 0, columns - stringWidth(truncationCharacter));
+		return appendWithInheritedStyleFromEnd(left, truncationCharacter);
 	}
@@ -99,0 +168,0 @@

package.json

 {
 	"name": "cli-truncate",
-	"version": "5.0.0",
+	"version": "5.1.0",
 	"description": "Truncate a string to a specific width in the terminal",
@@ -5,0 +5,0 @@ "license": "MIT",

readme.md

@@ -28,8 +28,11 @@ # cli-truncate
 
-cliTruncate('unicorns rainbow dragons', 6, {position: 'end'})
+cliTruncate('unicorns rainbow dragons', 6, {position: 'end'});
 //=> 'unico…'
 
 cliTruncate('\u001B[31municorn\u001B[39m', 4);
-//=> '\u001B[31muni\u001B[39m…'
+//=> '\u001B[31muni…\u001B[39m'
 
+> [!NOTE]
+> When truncating styled text (ANSI escapes), the truncation character inherits the style at the breaking point for `position: 'start'` and `position: 'end'`. This does not apply to `position: 'middle'`.
+
 // Truncate Unicode surrogate pairs
@@ -110,17 +113,17 @@ cliTruncate('uni\uD83C\uDE00corn', 5);
 
-cliTruncate('unicorns rainbow dragons', 20, {position: 'start', preferTruncationOnSpace: true})
+cliTruncate('unicorns rainbow dragons', 20, {position: 'start', preferTruncationOnSpace: true});
 //=> '…rainbow dragons'
 
-// without preferTruncationOnSpace
-cliTruncate('unicorns rainbow dragons', 20, {position: 'start'})
+// Without preferTruncationOnSpace
+cliTruncate('unicorns rainbow dragons', 20, {position: 'start'});
 //=> '…rns rainbow dragons'
 
-cliTruncate('unicorns rainbow dragons', 20, {position: 'middle', preferTruncationOnSpace: true})
+cliTruncate('unicorns rainbow dragons', 20, {position: 'middle', preferTruncationOnSpace: true});
 //=> 'unicorns…dragons'
 
-cliTruncate('unicorns rainbow dragons', 6, {position: 'end', preferTruncationOnSpace: true})
+cliTruncate('unicorns rainbow dragons', 6, {position: 'end', preferTruncationOnSpace: true});
 //=> 'unico…'
 
-// preferTruncationOnSpace would have no effect if space isn't found within next 3 indexes
-cliTruncate('unicorns rainbow dragons', 6, {position: 'middle', preferTruncationOnSpace: true})
+// preferTruncationOnSpace has no effect if space isn't found within 3 characters
+cliTruncate('unicorns rainbow dragons', 6, {position: 'middle', preferTruncationOnSpace: true});
 //=> 'uni…ns'
@@ -147,2 +150,3 @@ ```
 //=> 'unico'
+
 ```
@@ -149,0 +153,0 @@

No alert changes

Improved metrics

Total package byte prevSize

13083

19.86%

Lines of code

218

34.57%

Number of lines in readme file

155

2.65%

No dependency changes