Much talking is going on about Unit testing, Mocks and TDD in the PHP world. For the most this discussions surround object-oriented PHP code, frameworks and applications. Yet I would assert that the reality for PHP developers (me included) is dealing with PHP 4, PHP 5 migrated, or non-object oriented legacy applications which are near to impossible to bring under test.

He includes a "proof of concept" for a replacement mysql_query function (as created inside of Runkit) that sets up a "mocker" object that returns a "hello world" message when the mysql_query function is called.

Their implementation adds a tainted or not flag for every byte so that it is possible on invocation of mysql_query() to determine any kind of injection.

Unfortunately, Stefan also mentions two big issues it might have from the get-go: the overhead for the memory needed can slow things down and an incorrect parsing in their query handler could lead to injection attacks.

By help of the new function, you can create a mysqli_result object from a statement that returns data (SELECT and other - version dependent!). Then you can use the mysqli_result object to process the returned data: fetch results, access meta data - all you can also do using a mysqli_result object returned by mysqli_query().

Included in the post are a few code examples showing the simplicity of the function and how it can still be used with the standard mysql_* functions to grab the results.