eslint: no-fallthrough doesn't seem to work

Maybe I am missing something, but the following code snippet lints successfully when I enter it into http://eslint.org/demo/. I expected it to fail with no-fallthrough.

switch ("foo") {
case "foo":
case "bar":
    break;
default:
    throw new Error();
}

About this issue

Original URL
State: closed
Created 8 years ago
Comments: 19 (17 by maintainers)

Commits related to this issue

Fix: `no-fallthrough` empty case with comment (fixes #5799) — committed to eslint/eslint by alberto 8 years ago
Fix: `no-fallthrough` empty case with comment (fixes #5799) — committed to eslint/eslint by alberto 8 years ago
Fix: `no-fallthrough` empty case with comment (fixes #5799) — committed to eslint/eslint by alberto 8 years ago
Fix: `no-fallthrough` empty case with comment (fixes #5799) — committed to eslint/eslint by alberto 8 years ago
Merge pull request #5813 from eslint/issue4799 Fix: `no-fallthrough` empty case with comment (fixes #5799) — committed to eslint/eslint by nzakas 8 years ago

Most upvoted comments

We originally had this as an exception because it’s a pretty common way to say you want fall through (even JSLint allows it):

switch (something) {
    case 1:
    case 2:
        yay();
}

My opinion is that this should still not warn. However, this definitely should warn:

switch (something) {
    case 1:
        // yay();
    case 2:
        yay();
}

So, if I’ve read this issue correct, it’s really the latter case that is problematic and I’d say it’s a bug that it’s not being flagged right now. @Grandrath is that correct?

nzakas on Apr 7, 2016

Yup. If the two cases aren’t directly adjacent, then it should warn.

nzakas on Apr 11, 2016