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/*!
* detect-file <https://github.com/doowb/detect-file>
*
* Copyright (c) 2016-2017, Brian Woodward.
* Released under the MIT License.
*/
'use strict';
var fs = require('fs');
var path = require('path');
/**
* Detect the given `filepath` if it exists.
*
* ```js
* var res = detect('package.json');
* console.log(res);
* //=> "package.json"
*
* var res = detect('fake-file.json');
* console.log(res)
* //=> null
* ```
*
* @param {String} `filepath` filepath to detect.
* @param {Object} `options` Additional options.
* @param {Boolean} `options.nocase` Set this to `true` to force case-insensitive filename checks. This is useful on case sensitive file systems.
* @return {String} Returns the detected filepath if it exists, otherwise returns `null`.
* @api public
*/
module.exports = function detect(filepath, options) {
if (!filepath || (typeof filepath !== 'string')) {
return null;
}
if (fs.existsSync(filepath)) {
return path.resolve(filepath);
}
options = options || {};
if (options.nocase === true) {
return nocase(filepath);
}
return null;
};
/**
* Check if the filepath exists by falling back to reading in the entire directory.
* Returns the real filepath (for case sensitive file systems) if found.
*
* @param {String} `filepath` filepath to check.
* @return {String} Returns found filepath if exists, otherwise null.
*/
function nocase(filepath) {
filepath = path.resolve(filepath);
var res = tryReaddir(filepath);
if (res === null) {
return null;
}
// "filepath" is a directory, an error would be
// thrown if it doesn't exist. if we're here, it exists
if (res.path === filepath) {
return res.path;
}
// "filepath" is not a directory
// compare against upper case later
// see https://nodejs.org/en/docs/guides/working-with-different-filesystems/
var upper = filepath.toUpperCase();
var len = res.files.length;
var idx = -1;
while (++idx < len) {
var fp = path.resolve(res.path, res.files[idx]);
if (filepath === fp || upper === fp) {
return fp;
}
var fpUpper = fp.toUpperCase();
if (filepath === fpUpper || upper === fpUpper) {
return fp;
}
}
return null;
}
/**
* Try to read the filepath as a directory first, then fallback to the filepath's dirname.
*
* @param {String} `filepath` path of the directory to read.
* @return {Object} Object containing `path` and `files` if succesful. Otherwise, null.
*/
function tryReaddir(filepath) {
var ctx = { path: filepath, files: [] };
try {
ctx.files = fs.readdirSync(filepath);
return ctx;
} catch (err) {}
try {
ctx.path = path.dirname(filepath);
ctx.files = fs.readdirSync(ctx.path);
return ctx;
} catch (err) {}
return null;
}