Files
gemini-cli/packages/core/src/utils/textUtils.ts
2026-02-24 02:44:28 +00:00

106 lines
3.1 KiB
TypeScript

/**
* @license
* Copyright 2025 Google LLC
* SPDX-License-Identifier: Apache-2.0
*/
/**
* Safely replaces text with literal strings, avoiding ECMAScript GetSubstitution issues.
* Escapes $ characters to prevent template interpretation.
*/
export function safeLiteralReplace(
str: string,
oldString: string,
newString: string,
): string {
if (oldString === '' || !str.includes(oldString)) {
return str;
}
if (!newString.includes('$')) {
return str.replaceAll(oldString, newString);
}
const escapedNewString = newString.replaceAll('$', '$$$$');
return str.replaceAll(oldString, escapedNewString);
}
/**
* 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;
}
/**
* Detects the line ending style of a string.
* @param content The string content to analyze.
* @returns '\r\n' for Windows-style, '\n' for Unix-style.
*/
export function detectLineEnding(content: string): '\r\n' | '\n' {
// If a Carriage Return is found, assume Windows-style endings.
// This is a simple but effective heuristic.
return content.includes('\r\n') ? '\r\n' : '\n';
}
/**
* Truncates a string to a maximum length, appending a suffix if truncated.
* @param str The string to truncate.
* @param maxLength The maximum length of the string.
* @param suffix The suffix to append if truncated (default: '...[TRUNCATED]').
* @returns The truncated string.
*/
export function truncateString(
str: string,
maxLength: number,
suffix = '...[TRUNCATED]',
): string {
if (str.length <= maxLength) {
return str;
}
return str.slice(0, maxLength) + suffix;
}
/**
* Safely replaces placeholders in a template string with values from a replacements object.
* This performs a single-pass replacement to prevent double-interpolation attacks.
*
* @param template The template string containing {{key}} placeholders.
* @param replacements A record of keys to their replacement values.
* @returns The resulting string with placeholders replaced.
*/
export function safeTemplateReplace(
template: string,
replacements: Record<string, string>,
): string {
// Regex to match {{key}} in the template string. The regex enforces string naming rules.
const placeHolderRegex = /\{\{(\w+)\}\}/g;
return template.replace(placeHolderRegex, (match, key) =>
Object.prototype.hasOwnProperty.call(replacements, key)
? replacements[key]
: match,
);
}