Any plans for a migration guide?

[JCMais]

Updating from NaN 1.x to 2.x is getting more harder than I thought.

[winfinit]

converted examples in node-addon-examples may make it a bit easier (pull request is pending, but you can see nan_2.x and nan_1.x here: https://github.com/winfinit/node-addon-examples)

also what helped me a lot is to look through https://github.com/nodejs/nan/tree/master/test

[kkoopa]

@rvagg said he was working on one

[ivan]

The converter script in #376 (comment) was very helpful for me

[mscdex]

+1

[eljefedelrodeodeljefe]

Good hint @winfinit . Found everything I needed in the test directory.

[lovell]

The biggest gotcha I've run into between nan v1 and v2 is a change to the Buffer creation methods where ownership of the underlying data is transferred.

In nan v1, the "take ownership" method is NanBufferUse which results in delete[] being called on the data during GC.

In nan v2, the "take ownership" method is Nan::NewBuffer which results in free() being called.

[JCMais]

@lovell I had a bunch of memory corruption because of this exact change. Took awhile to figure it out.

[mathiask88]

So if I use new for memory allocation then I need to use BufferCopy and cannot use the allocated memory block because it is removed with free()?

[kkoopa]

Supply a FreeCallback that calls delete.

[mathiask88]

@kkoopa Ah thanks, I read over that one. Is there a nan wrapper for node::smalloc::FreeCallback and node::Buffer::FreeCallback callback? And what is the hint argument?

[kkoopa]

https://github.com/nodejs/nan/blob/master/nan.h#L1218
The hint argument is user data.

[rvagg]

https://nodesource.com/blog/cpp-addons-for-nodejs-v4 here 'tis

[JCMais]

Great!