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/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* 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 (const byte of sample) {
// 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 (byte === 0) {
return true;
}
}
// If no NULL bytes were found in the sample, we assume it's text.
return false;
}
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