让 Node 自己来做这个工作。
const path = require('path');
const relative = path.relative(parent, dir);
return relative && !relative.startsWith('..') && !path.isAbsolute(relative);
它也为您进行标准化。
const path = require('path');
const tests = [
['/foo', '/foo'],
['/foo', '/bar'],
['/foo', '/foobar'],
['/foo', '/foo/bar'],
['/foo', '/foo/../bar'],
['/foo', '/foo/./bar'],
['/bar/../foo', '/foo/bar'],
['/foo', './bar'],
['C:\\Foo', 'C:\\Foo\\Bar'],
['C:\\Foo', 'C:\\Bar'],
['C:\\Foo', 'D:\\Foo\\Bar'],
];
tests.forEach(([parent, dir]) => {
const relative = path.relative(parent, dir);
const isSubdir = relative && !relative.startsWith('..') && !path.isAbsolute(relative);
console.log(`[${parent}, ${dir}] => ${isSubdir} (${relative})`);
});
也可在 Windows 上跨驱动器运行。
[/foo, /foo] => false ()
[/foo, /bar] => false (..\bar)
[/foo, /foobar] => false (..\foobar)
[/foo, /foo/bar] => true (bar)
[/foo, /foo/../bar] => false (..\bar)
[/foo, /foo/./bar] => true (bar)
[/bar/../foo, /foo/bar] => true (bar)
[/foo, ./bar] => false (..\Users\kozhevnikov\Desktop\bar)
[C:\Foo, C:\Foo\Bar] => true (Bar)
[C:\Foo, C:\Bar] => false (..\Bar)
[C:\Foo, D:\Foo\Bar] => false (D:\Foo\Bar)