[#RSRP-55342] Add "remove empty event handler"

ReSharper

Add "remove empty event handler"

Created: 03 Jan 08 02:17 Updated: 14 Apr 08 15:02

Component/s:

Refactorings - Safe Delete

Fix Version/s:

4.5

Security Level:

Everybody (All jira users)

Original Estimate:

Unknown

Remaining Estimate:

Unknown

Time Spent:

Unknown

File Attachments:

None

Image Attachments:

1. RemoveEmptyHandler.png
(9 kb)

Description

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Along with "safe delete", add "remove empty event handler" refactoring action to a method, if it is empty, private and used only with += and -= operators for some delegate/event. Since method has usages it cannot be marked as "unused". Action should remove these usages as well.

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Ilya Ryzhenkov - 14 Jan 08 13:47

It is not always safe to delete such method. If it is assumed, that there are always at least one subscriber, there could be ommitted checks for null. Like this:

public event EventHandler SomethingChanged = EmptyHandler;

private void EmptyHandler(object sender, EventArgs e) {};

protected virtual void OnSomethingChanged(EventArgs e)
{
 SomethingChanged(this, e); // not check for null is ommited
}

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Alex Martsynkevich - 14 Jan 08 15:36

Right, that's why I suggest to add this feature as another refactoring function, not the same as "safe delete". In most cases (and it is a proper behavior) there's a check whether delegate is null before invoking it.
In fact, I'd even suggest considering allowing this feature on non-empty event handlers. It would be a useful shortcut, since the method and it's usage are likely to be quite far apart in the code. As long as user can undo the action.

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Ilya Ryzhenkov - 14 Jan 08 15:50

As far as I understand, we just need to remove subscribe/unsubscribe usages when safe-deleting method. Probably also suppress conflict if method is void and empty. Then you can easily do what you want by ignoring conflicts, if they appear. Am I right?

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Ilya Ryzhenkov - 16 Jan 08 12:49

So, why safe delete with described additions won't work for you?

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Alex Martsynkevich - 16 Jan 08 15:31

If safe delete dialog removes usages (perhaps, also marks them with something lower than "stop" severity at conflicts step), I don't see a problem with it. You're right – one less context action is probably a better way.