/**
* Ignore file handling (.gitignore, .ignore).
*
* Uses the `ignore` package for proper gitignore semantics.
*/
import fs from 'node:fs/promises';
import path from 'node:path';
import ignore, { type Ignore } from 'ignore';
/** Default patterns to always ignore */
const DEFAULT_IGNORE = [
// Hidden files/folders (start with dot)
'.*',
// Common non-content directories
'node_modules',
// OS junk files
'Thumbs.db',
// Editor temp files
'*.swp',
'*.swo',
'*~',
];
/** Pattern matcher for ignore rules */
export interface IgnoreMatcher {
isIgnored(relativePath: string): boolean;
}
/**
* Check if a relative path falls under any of the include prefixes.
* Matching is recursive — prefix "data" matches "data", "data/foo", "data/foo/bar".
*/
function isIncludedPath(relativePath: string, includePaths: readonly string[]): boolean {
if (includePaths.length === 0) return false;
const normalized = relativePath.replace(/^\/+/, '');
return includePaths.some(
(prefix) =>
normalized === prefix ||
normalized.startsWith(prefix + '/'),
);
}
/**
* Create an ignore matcher from patterns.
* Paths matching `includePaths` are never ignored (whitelist override).
*/
export function createIgnoreMatcher(
patterns: string[],
includePaths: readonly string[] = [],
): IgnoreMatcher {
const ig: Ignore = ignore().add(DEFAULT_IGNORE).add(patterns);
return {
isIgnored(relativePath: string): boolean {
const normalized = relativePath.replace(/^\/+/, '');
if (!normalized) return false;
if (isIncludedPath(normalized, includePaths)) return false;
return ig.ignores(normalized);
},
};
}
/**
* Load ignore patterns from a directory.
* Looks for .gitignore and .ignore files.
*/
export async function loadIgnorePatterns(dir: string): Promise<string[]> {
const patterns: string[] = [];
for (const filename of ['.gitignore', '.ignore']) {
try {
const content = await fs.readFile(path.join(dir, filename), 'utf8');
const lines = content
.split('\n')
.map((line) => line.trim())
.filter((line) => line && !line.startsWith('#'));
patterns.push(...lines);
} catch {
// File doesn't exist, that's fine
}
}
return patterns;
}
/**
* Create an ignore matcher for a directory.
* Paths matching `includePaths` are never ignored (whitelist override).
*/
export async function createIgnoreMatcherForDir(
dir: string,
includePaths: readonly string[] = [],
): Promise<IgnoreMatcher> {
const patterns = await loadIgnorePatterns(dir);
return createIgnoreMatcher(patterns, includePaths);
}
