Fix null ref in initialize-parameter.

[CyrusNajmabadi]

No description provided.

[CyrusNajmabadi]

Tagging @dotnet/roslyn-ide @jmarolf

[jmarolf]

👍

[jasonmalinowski]

Shouldn't that be getting an EndOfFile token with the parent as the compilation syntax?

[CyrusNajmabadi]

GetPreviousToken on an EOF token can return a .None token with a null parent.

I considered this when i originally wrote the code. but i thought FirstAncestorOrSelf was an extension method and would handle the 'null' case (like IsKind and many of the other node-extension methods do). It turned out this was an instance method. Hence boom.

[jasonmalinowski]

All the more reason to hate extension methods that accept null receivers. 😉

[CyrusNajmabadi]

i love them! :D

[CyrusNajmabadi]

though, with ?. they're probably not necessary any more.

[jmarolf]

@mattwar probably still gets flashbacks from when he changed all those extension methods to instance methods and discovered that all if them just returned null if passed null

[jasonmalinowski]

There's a part of me that would be happy to see a change where everything did ?. But the bug fallout and massive diff would be crazy...

[Pilchie]

GetPreviousToken on an EOF token can return a .None token with a null parent.

The only case for that is an empty file, right?

[mattwar]

sure would be nice to have null checking compiler.

[CyrusNajmabadi]

The only case for that is an empty file, right?

Or any file when you're on the first token.

[Pilchie]

Ah, got it. I was confused by the reference to EOF token before.