[webkit-dev] Isolated world tests

[Adam Barth]

On Wed, Jul 1, 2009 at 7:50 PM, Maciej Stachowiak<mjs at apple.com> wrote:
> We generally wouldn't accept WebKit features that only work with V8, even if
> other ports may not immediately plan to use them.

I support this principle.

> I haven't thought through whether this particular feature
> should be an exception.

The main arguments are as follows:

1) Isolated worlds is not a web platform feature.  Adding the feature
to V8 and not to JSC does not create an incompatibility between the
two engines.  The observable behavior from web content is the same.

2) The purpose of implementing isolated worlds is so the app can
implement an app-specific feature (extensions).  Implementing
extensions in another app requires a lot more than just isolated
worlds.

3) I don't foresee the implementation touching any source files
outside of WebCore/bindings/v8.  Other ports do not need to bear any
costs because of isolated worlds.

> In general, I think using regression tests for features that are not
> directly exposed to Web content, but implemented in WebCore/WebKit, is
> reasonable. For example we have tests that check that WebKit's delegate
> methods relating to load progress are dispatched in the correct order.

Perhaps I've been indoctrinated into the cult, but I wouldn't want to
work on something without writing tests.

Adam