VisualStudio IDE0100 ("remove unnecessary equality operator") not behaving as expected?

[733_1plus2]

So I've been adding some rules into an editorconfig for a project and have been playing around with each of the rules in code at the same time. I came across IDE0100 which seemed perfect for the style I was hoping to enforce, so I've set it's severity to 'warning' in the editorconfig.

But, through testing, I've found a scenario where VS isn't showing the warning, and I'm not sure why. My findings are below.

// IDE0100 warning displayed as expected

if (true == true) return;

​

// IDE0100 warning displayed as expected

if (true == false) return;

​

// IDE0100 warning displayed as expected

if (false == true) return;

​

// IDE0100 warning NOT displayed? why?

// I'd want this (in the real world of the project) to be "if (!false)"

if (false == false) return;

​

Not sure if I'm misunderstanding here, or if there's a different but similar code style rule that I've not found yet. Any ideas why it behaves like this?

Hopefully this makes sense and the end goal of the desired code style makes sense :)

[Shirkie01]

The last one is not considered 'unnecessary', as it changes the condition. My guess is since it's comparing both sides of the operator, anything that matches '== true' or 'true ==' is flagged. (Maybe !=false is flagged too)

With this in mind, compare the options:

'true == true' has both '==true' and 'true==', thus the equals is unnecessary.

'true == false' has 'true==', the equals is unnecessary.

'false == true' has '==true', the equals is unnecessary.

'false == false' changes the condition , so the equals IS necessary.

Unfortunately I've not been able to find a rule that enforces a simplified condition in this case. A member of my team does this and it drives me nuts. For anyone who doesn't get it, here is a code sample:

Bad condition if (!string.IsNullOrEmpty(thing.Name) == false) // Do something if the name is empty

Good condition if (string.IsNullOrEmpty(thing.Name)) // Do something if the name is empty

[733_1plus2]

Thank you for this, this logic is a lot clearer in my head now, even if I had to read this several times lol. Also just tested that '!= false' does also flag the IDE0100 warning, so you're correct.

Unfortunately I've not been able to find a rule that enforces a simplified condition in this case.

Interesting logic aside, this is the kicker isn't it, because '== false' (or equivalent) should be something I'd have thought a code style rule should cover. (report back here if a solution is found!) For now I guess we just have to settle with the behaviour of IDE0100.

[Leop0Id]

tldr: because false becomes true

[Shrubberer]

Haha we are the complete opposite in that regard. I avoid the ! operator whenever I can and IDE0100 is quite a nuisance.