Purpose, goals

• built-in, very easy testing
• gain exactness
• good diagnostics

Definition

• series of discrete operations with boolean result, marked as tests

Syntax

overall structure

• plan(2); tests; # done
• plan(*); tests; tests-done(); # names subject to discussion ;-)

single tests

we have two proposal:

adverb on operators

                $x eq 'foo'     :ok('Test descriptions');
                $x == 23        :ok('explicit numeric test');
                ?$x             :ok<stuff>      # used to be ok($x, 'stuff');
                try { dispatch() } :ok<...>     # used to be lives_Ok { ... }, '...';

(it was also proposed to name it :test instead of :ok)

pros:

• good diagnose of output
• force exact comparison semantics
• no pollution of namespace

cons:

• have to auto-generate ops with adverbs
• more complicated grammar needed
• the fact that a line contains a test is somewhere in the middle, so not too obvious

normal sub calls, like now

                ok $x eq 'foo', 'description';
                dies_ok { ... }, 'description';

pros:

• easier to implement
• it's been proven to work out well
• visually tests are very easy to spot

cons:

• it's *very* hard to get good diagnostics out of failed tests (advanced macro fiddling needed)
• clutters up namespace
• if we don't deprecate is(), we have to find sane comparison semantics, fix up the tests (we have to do that anyway...) and educate our test writes. Currently infix:<eqv> is a candidate (advocated by pmichaud, because it's very dwimmy), infix:<eq> being another (advocated by mority, because it's very simple and easy to explain).

Backends and standard backend

• all the test logic should be easily overridable (for example for storing

test results in a db, or different test output format)

• simplest idea:

there's a Test::Backend object in $*TEST_BACKEND, and plan() class the .plan method, :ok('...') adverbs on ops call.

• the default backend will emit TAP output
• the default backend will consider a test run failed if any single test failed, or in case of plan mismatch