Disable JSHint warning: Expected an assignment or function call and instead saw an expression

Question

I have the following line:

imageUrl && (data.imageUrl = imageUrl);

For this line, JSHint complains:

 Expected an assignment or function call and instead saw an expression.

I understand the warning, but I want to disable it. I can’t find the way how to do it. Any idea?

It's pointlessly (imo) tricky. Why not use an if, then the warning won't happen. — The Archetypal Paul, Dec 23 '14 at 16:08
@Paul Because I use this pattern a lot. I prefer to ignore this kind of error specifically for the lines I used it (not globally). — Naor, Dec 23 '14 at 16:12
@torazaburo, no, that other question is the other way around (jshint finding an assignment when it expected an expression) — The Archetypal Paul, Dec 23 '14 at 16:20
And that other question is about jslint - and the jshint answer there isn't the best, IMO. — The Archetypal Paul, Dec 23 '14 at 16:21
They don't give the `ignore:line` option. Otherwise, it's basically the same. Probably could be merged. — The Archetypal Paul, Dec 23 '14 at 16:25

The Archetypal Paul · Accepted Answer · 2014-12-23T16:16:49.597

45

If it really is just that one line

imageUrl && (data.imageUrl = imageUrl); // jshint ignore:line

I am a fan of writing code so it doesn't produce warnings, though, even if this means taking special action to do so. So I'd prefer

if (imageUrl) data.imageUrl = imageUrl;

edited Dec 23 '14 at 16:16

answered Dec 23 '14 at 16:09

Know what? Took your advice! `if (imageURL) data.imageUrl = imageUrl` looks similar and better. Thanks! – Naor Dec 23 '14 at 16:14
What about `a || (a = [])`? Have any improvement for that? – Naor Dec 23 '14 at 16:19
`if (!a)`? `if (a.length != 0)`? Depends on what you're trying to do. Or `if (a) ; else a=[];`. Please don't do that one! (you'll get a different warning, in any case) – The Archetypal Paul Dec 23 '14 at 16:23
Thanks! Have any idea what about: `a = (b === c)`? I get `Expected an assignment or function call and instead saw an expression.` – Naor Dec 23 '14 at 16:54
OK, that's an odd one. I don't immediately see why it's complaining about that. On the other hand, jshint.com doesn't complain about it, so are you sure that's exactly what you used? No chance the first `=` was accidentally `==`? (which does result in your error) – The Archetypal Paul Dec 23 '14 at 16:55
And this comment chains is getting long. You should probably edit your question with all the statements/expressions you'd like to suppress warnings for – The Archetypal Paul Dec 23 '14 at 16:58

score 41 · Answer 2 · answered Dec 23 '14 at 16:04

41

Include a /* jshint expr: true */ comment in your Javascript.

answered Dec 23 '14 at 16:04

Paul Roub

6

That turns it off globally, and so may suppress valid warnings elsewhere, unless you put it inside the offending function – The Archetypal Paul Dec 23 '14 at 16:06

2 Answers2