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/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Calculates the maximum width of a multi-line ASCII art string.
* @param asciiArt The ASCII art string.
* @returns The length of the longest line in the ASCII art.
*/
export const getAsciiArtWidth = (asciiArt: string): number => {
if (!asciiArt) {
return 0;
}
const lines = asciiArt.split('\n');
return Math.max(...lines.map((line) => line.length));
};
/**
* Checks if a Buffer is likely binary by testing for the presence of a NULL byte.
* The presence of a NULL byte is a strong indicator that the data is not plain text.
* @param data The Buffer to check.
* @param sampleSize The number of bytes from the start of the buffer to test.
* @returns True if a NULL byte is found, false otherwise.
*/
export function isBinary(
data: Buffer | null | undefined,
sampleSize = 512,
): boolean {
if (!data) {
return false;
}
const sample = data.length > sampleSize ? data.subarray(0, sampleSize) : data;
for (let i = 0; i < sample.length; i++) {
// The presence of a NULL byte (0x00) is one of the most reliable
// indicators of a binary file. Text files should not contain them.
if (sample[i] === 0) {
return true;
}
}
// If no NULL bytes were found in the sample, we assume it's text.
return false;
}
/*
* -------------------------------------------------------------------------
* Unicode‑aware helpers (work at the code‑point level rather than UTF‑16
* code units so that surrogate‑pair emoji count as one "column".)
* ---------------------------------------------------------------------- */
export function toCodePoints(str: string): string[] {
// [...str] or Array.from both iterate by UTF‑32 code point, handling
// surrogate pairs correctly.
return Array.from(str);
}
export function cpLen(str: string): number {
return toCodePoints(str).length;
}
export function cpSlice(str: string, start: number, end?: number): string {
// Slice by code‑point indices and re‑join.
const arr = toCodePoints(str).slice(start, end);
return arr.join('');
}
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