🚀 Feature: Add option to follow symlinks found by glob patterns

[mbeerta-factset]

Prerequisites

• [x] Checked that your issue hasn't already been filed by cross-referencing issues with the faq label
• [x] Checked next-gen ES issues and syntax problems by using the same environment and/or transpiler configuration without Mocha to ensure it isn't just a feature that actually isn't supported in the environment in question or a bug in your code.
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Description

This is related to #1223 where util.lookupFiles does not follow symlinks and this still happens if provided with a glob pattern. The solution would be to add a {follow: true} argument to the glob.sync call.

Steps to Reproduce

Create a symlink to a directory containing test files, call mocha with a glob to that directory.

Expected behavior: Tests in symlinked folders will be executed

Actual behavior: Tests are ignored

Reproduces how often: every time

Versions

• The output of mocha --version and node node_modules/.bin/mocha --version: latest
• The output of node --version:
• The version and architecture of your operating system: X64 Linux
• Your shell (bash, zsh, PowerShell, cmd, etc.): bash
• Your browser and version (if running browser tests): -
• Any other third party Mocha related modules (with versions): -
• The code transpiler being used: -

Additional Information

I'm happy to create a pull request, however i'm not familiar with the implications such a change might have.

[plroebuck]

I'm not sure if we specify a minimum Windows OS version, so someone else will need to interpret its impact. Unsure whether this was done intentionally to "return the same results" on all platforms.

See NTFS symlinks.

[bluelovers]

fast-glob is support followSymlinkedDirectories

so i think can replace glob => fast-glob in dependencies

[Bamieh]

Maybe this should be added as an additional flag rather than the default behavior? I added the "future" tag since I believe it might be a good idea to land yargs first (https://github.com/mochajs/mocha/pull/3556) (feel free to disagree)

[boneskull]

Agree it would probably not be a great idea to make this the default behavior.

@mbeerta-factset Are there any workarounds at present time?

[mbeerta-factset]

unfortunately not, but i had the same thoughts of making this switchable. Might be reusing the --preserve-symlinks option a viable approach (although it is also passed to the node runtime)?

[shubham-rocko]

Hi, I would love to do this issue if it isn't fixed yet.

[cristian-spiescu]

I'm posting here my current workaround (via monkeypatching) for this:

mocha-monkeypatched.js:

// monkeypatching libs
var Module = require('module');
var originalRequire = Module.prototype.require;

let globMonkeyPatched = false;

Module.prototype.require = function () {
    const original = originalRequire.apply(this, arguments);

    if (!globMonkeyPatched && "glob" === arguments[0]) {
        // BUG #1: cf. https://github.com/mochajs/mocha/issues/3584
        // mocha doesn't detect test files in linked dirs
        var originalSync = original.sync;
        original.sync = function () {
            const options = arguments[1];
            options.follow = true;
            return originalSync.apply(this, arguments);
        }
        globMonkeyPatched = true;
    }

    return original;
};

// BUG #2: cf. https://github.com/paulmillr/chokidar/issues/987
// mocha cannot watch multiple file extensions; hence this workaround
process.argv.push("-w", "--watch-files", ".");

// INIT_CWD only exists when launched w/ npm run ...; if needed to run as stand alone, a solution around process.argv[1] can be built
require(process.env.INIT_CWD + "/node_modules/mocha/bin/_mocha");

package.json:

    "test": "set NODE_OPTIONS=--preserve-symlinks && node mocha-monkeypatched"

NOTE: I also discovered another issue regarding linked files, but related to watching.

[JoshuaKGoldberg]

👍 that making this the default behavior is too scary of a change, but that as a new option it would be good.