addons/update.js does not work as expected with prototypes

[slorber]

Being able to use addons/update.js with a prototype seems to be a goal of the addon according to this line:

react/src/addons/update.js

Line 29 in 3eb3641

return copyProperties(new x.constructor(), x);

Since we use object constructor instead of just {}

When updating an object with a prototype, the prototype is kept, as expected, but the copyProperties.js include prototype methods as object properties.

This is probably because of this loop:

react/src/vendor/core/copyProperties.js

Line 39 in 8a47813

for (var k in v) {

See this http://jsfiddle.net/QVjLw/

I think the loop should be

    for (var k in v) {
        if ( v.hasOwnProperty(k) ) {
           obj[k] = v[k];
        }
    }

Instead of

    for (var k in v) {
           obj[k] = v[k];
    }

It would be nice to not pollute the object attributes with unnecessary methods and keep them in the prototype

[sophiebits]

Perhaps this is supposed to use mergeInto instead of copyProperties.

[zpao]

Using mergeInto seems like a sane option. I think we want to kill copyProperties anyway. cc @petehunt

[slorber]

that seems to be fine with mergeInto yes :)

By the way, it would be nice to document the fact that we can use the update function with a prototyped object.

Not really related but doesn't know if it worth opening an issue for that, but I wonder why there is no $unset operator. Is there a way with current operators to delete an attribute from the tree? I tried to $set: undefined but it... sets undefined and does not remove the element

[syranide]

@slorber Not disagreeing with your idea, but it's generally preferable to set it to undefined rather than delete it (as per how V8 handles objects).

[chenglou]

Update now uses the Object.assign shim, so this should be solved.

[slorber]

It seems to work fine for me since migration to 0.12.0