Debug builds of the SDK

Problem

The Flex SDK has a general policy of garbage-in, garbage-out. If an application sends in bad data to a function, the result is undefined; we don't typically do anything to detect or report the error.

One of the reasons for this decision is to keep footprint and code size down; why add error code for situations that should not in general happen?

However, it would be to the advantage of our developers to have more information, especially at development time, about failures that are occuring and why.

This feature request is for some system that would enable the SDK to create 'debug' SWC files which included things like thrown errors, in addition to the release build which did not. Then Flex Builder could use this mechanism to produce the resulting debug SWF file with error information.

More Information

There is some capability in ActionScript3 already for conditional compilation: the Config:: language feature enables us to write blocks of code that are conditionally built in. It might be possible for us to build on this language feature to then produce alternate SWCs.

Solution

The Flex SDK is where most of the work for this feature would reside. We would need to enable the mechanism for creating the debug SWCs and then start instrumenting our code to throw appropriate errors. At that point, Flex Builder could use that capability to produce a debug build for developers that threw those errors, or a release build that did not.

The feature is a 'B' Feature for Flex 4. It seems doubtful, given the other A and B features, that it would make it into Flex 4, but should stay on the list for now as something that we should probably have eventually. There is also no point in having an SDK feature like this if tooling doesn't know how to take advantage of it, and the tools don't have time in Flex 4 to address.