basant307/AI_Governance_Project

1import sliceAnsi from 'slice-ansi';2import stringWidth from 'string-width';3 4function getIndexOfNearestSpace(string, wantedIndex, shouldSearchRight) {5	if (string.charAt(wantedIndex) === ' ') {6		return wantedIndex;7	}8 9	const direction = shouldSearchRight ? 1 : -1;10 11	for (let index = 0; index <= 3; index++) {12		const finalIndex = wantedIndex + (index * direction);13		if (string.charAt(finalIndex) === ' ') {14			return finalIndex;15		}16	}17 18	return wantedIndex;19}20 21export default function cliTruncate(text, columns, options = {}) {22	const {23		position = 'end',24		space = false,25		preferTruncationOnSpace = false,26	} = options;27 28	let {truncationCharacter = '…'} = options;29 30	if (typeof text !== 'string') {31		throw new TypeError(`Expected \`input\` to be a string, got ${typeof text}`);32	}33 34	if (typeof columns !== 'number') {35		throw new TypeError(`Expected \`columns\` to be a number, got ${typeof columns}`);36	}37 38	if (columns < 1) {39		return '';40	}41 42	const length = stringWidth(text);43 44	if (length <= columns) {45		return text;46	}47 48	if (columns === 1) {49		return truncationCharacter;50	}51 52	// ANSI escape sequence constants53	const ANSI = {54		ESC: 27,55		LEFT_BRACKET: 91,56		LETTER_M: 109,57	};58 59	const isSgrParameter = code => (code >= 48 && code <= 57) || code === 59; // 0-9 or ;60 61	function leadingSgrSpanEndIndex(string) {62		let index = 0;63		while (index + 2 < string.length && string.codePointAt(index) === ANSI.ESC && string.codePointAt(index + 1) === ANSI.LEFT_BRACKET) {64			let j = index + 2;65			while (j < string.length && isSgrParameter(string.codePointAt(j))) {66				j++;67			}68 69			if (j < string.length && string.codePointAt(j) === ANSI.LETTER_M) {70				index = j + 1;71				continue;72			}73 74			break;75		}76 77		return index;78	}79 80	function trailingSgrSpanStartIndex(string) {81		let start = string.length;82		while (start > 1 && string.codePointAt(start - 1) === ANSI.LETTER_M) {83			let j = start - 2;84			while (j >= 0 && isSgrParameter(string.codePointAt(j))) {85				j--;86			}87 88			if (j >= 1 && string.codePointAt(j - 1) === ANSI.ESC && string.codePointAt(j) === ANSI.LEFT_BRACKET) {89				start = j - 1;90				continue;91			}92 93			break;94		}95 96		return start;97	}98 99	function appendWithInheritedStyleFromEnd(visible, suffix) {100		const start = trailingSgrSpanStartIndex(visible);101		if (start === visible.length) {102			return visible + suffix;103		}104 105		return visible.slice(0, start) + suffix + visible.slice(start);106	}107 108	function prependWithInheritedStyleFromStart(prefix, visible) {109		const end = leadingSgrSpanEndIndex(visible);110		if (end === 0) {111			return prefix + visible;112		}113 114		return visible.slice(0, end) + prefix + visible.slice(end);115	}116 117	if (position === 'start') {118		if (preferTruncationOnSpace) {119			const nearestSpace = getIndexOfNearestSpace(text, length - columns + 1, true);120			const right = sliceAnsi(text, nearestSpace, length).trim();121			return prependWithInheritedStyleFromStart(truncationCharacter, right);122		}123 124		if (space) {125			truncationCharacter += ' ';126		}127 128		const right = sliceAnsi(text, length - columns + stringWidth(truncationCharacter), length);129		return prependWithInheritedStyleFromStart(truncationCharacter, right);130	}131 132	if (position === 'middle') {133		if (space) {134			truncationCharacter = ` ${truncationCharacter} `;135		}136 137		const half = Math.floor(columns / 2);138 139		if (preferTruncationOnSpace) {140			const spaceNearFirstBreakPoint = getIndexOfNearestSpace(text, half);141			const spaceNearSecondBreakPoint = getIndexOfNearestSpace(text, length - (columns - half) + 1, true);142			return sliceAnsi(text, 0, spaceNearFirstBreakPoint) + truncationCharacter + sliceAnsi(text, spaceNearSecondBreakPoint, length).trim();143		}144 145		return (146			sliceAnsi(text, 0, half)147			+ truncationCharacter148			+ sliceAnsi(text, length - (columns - half) + stringWidth(truncationCharacter), length)149		);150	}151 152	if (position === 'end') {153		if (preferTruncationOnSpace) {154			const nearestSpace = getIndexOfNearestSpace(text, columns - 1);155			const left = sliceAnsi(text, 0, nearestSpace);156			return appendWithInheritedStyleFromEnd(left, truncationCharacter);157		}158 159		if (space) {160			truncationCharacter = ` ${truncationCharacter}`;161		}162 163		const left = sliceAnsi(text, 0, columns - stringWidth(truncationCharacter));164		return appendWithInheritedStyleFromEnd(left, truncationCharacter);165	}166 167	throw new Error(`Expected \`options.position\` to be either \`start\`, \`middle\` or \`end\`, got ${position}`);168}169