Resharper structural search and replace Part II - Custom Quick Fixes

In Part I I covered finding usages with Resharper's 'Search with Pattern' feature.

Now lets turn our focus to replacing usages with our own snippets and creating our own custom quick fixes!

Consider this erroneous code sample you might encounter:

private void HandleMessage(object data)
{
    Address address = data as Address;//should just cast to Address here
    if(address.StreetName == "easy street")
    {
        //handle...
    }
}

Why erroneous you say? Well if you expect data to only ever be an Address then you should cast to it instead of using the as operator - That way at least you'll get an InvalidCastException instead of a NullPointerException.
sidenote1 there is obviously a time and place for the as operator I'm just giving an example of where a cast is more appropriate

We'll add a pattern that will replace:

Address address = data as Address;

with

var address = (Address)data;

This time open the Patterns Catalog, Resharper -> Options -> Code Inspection -> Custom Patterns

Click Add Pattern and enter the following details:

Search for:

$type$ $var$ = $expr$ as $type$;

Replacing with:

var $var$ = ($type$)$expr$;

Give it a nice description:

Replace 'as' with cast to $type$

Note we are using the $type$ in the Description, we'll see why later. Also set pattern severity to 'Show as hint'

Now you can Save the Pattern and press 'Search Now' which will find our usage as detailed above and give you the option to Replace it (with undo naturally!)

The real fun comes when you're back in the code (assuming you haven't replaced it yet)

Put the cursor/caret at the start of the Address address line and press the famous Alt-Enter:

You now have your own quick fix! It won't underline which is what we want because we only want to use it in specific places, most likely not every place. Notice how the $type$ holder in the Description has been replaced with the type Address, which makes it very clear what the quick fix does.

sidenote2 seems like a lot of trouble to go to for something that can be fixed fairly easily manually?? depends who you've let loose on your code and how many times you have to replace it