#summary A rewrite of Test::Builder
#labels Featured,Phase-Requirements

= Introduction =

Test::Builder2 is a rewrite of Test::Builder to support the needs of post-modern test modules.


= Goals =

 * Implement everything Test::Builder does
 * Allow many "builder" classes and objects in the same test process
 * Allow modules to customize test behavior without interfering with other modules
 * Eliminate the "$Level" hack
 * Allow beginning/end of test actions
 * Allow output formats other than TAP
 * Allow tests before a plan has been declared
 * "Until declared done" style plan.
 * A better way to add tests at the end (a la Test::NoWarnings).
 * Additive plans.
 * Composable test comparisons


= Use Cases =

  * die-on-fail
  * debug-on-fail
  * stack-trace-on-fail
  * Use test libraries as assertions in running code (see Carp::Assert::More and Test::AtRuntime)
  * Implement Test::Builder with Test::Builder2
  * Implement one of [http://www.phpunit.de/pocket_guide/3.3/en/phpunit-book.html#logging PHPUnit's Logging Formats] as output.
  * Have two test libraries adding the same named attribute and not interfere
  * Have a test library using a Test::Builder2 subclass
  * Simple alternative test output format:  + for a pass, - for a fail.
  * Have a test library wrap Test::More's functions (instead of using Test::Builder).
  * Add a new test result type
  * Build up a test plan by adding to it test block by test block
  * Record what function the test was called in (to better support xUnit style results)
  * Try to silently deal with a forked test
  * Deal with threaded tests
  * [POSIX http://www.gnu.org/software/dejagnu/manual/x47.html#posix] test output
  * Use test functions as generic comparison functions.
  * Multiple test output objects (ie. spit out XML and send email on failure)
  * Publish test output over HTTP


= Internals =

For the most part, chromatic's write up of [http://www.perl.com/pub/a/2005/07/28/test_builder_p6.html Porting Test::Builder to Perl 6] gives a good idea of how the redesign will go.  Basically, break up the monolithic Test::Builder singleton object into a conglomerate of many objects so pieces can be reused and replaced.  Only certain key bits, such as the test counter and history, need be singletons.