!3 Calling a method from an action
The keywords of an action are concatentated together, with spaces between and converted into a valid Java identifier. This is done using [[''extended camel casing''][.FitLibraryUserGuide.ExtendedCamelCase]].
!3 Rules for coloring
 * If an action returns a boolean value, the 'keywords' of that action are colored green if the returns true. If it returns false or throws an exception, it colors it red.
 * A 'check'' special action colors the last cell, containing the expected value, just like ''!-ActionFixture-!''
 * A 'reject' or 'not' special action color the action green if the action returns false or throws an exception. Otherwise it colors it red.
 * An 'ensure' special action colors the action red if the action returns false or throws an exception. Otherwise it colors it green.
!3 Auto-Wrapping
The value returned by the method corresponding to an action may be auto-wrapped with a fixture, as follows:
 * A ''Set'' object is auto-wrapped with a ''!-SetFixture-!''.
 * An ''Object[]'', ''Collection'' or ''Iterator'' is wrapped with an ''!-ArrayFixture-!''.
 * An 'Object' is wrapped with a ''!-DoFixture-!''. But only if it's not one of the above, nor a ''Fixture'', and doesn't have a ''static Object parse(String)'' method.
This fixture object, or the one returned explicitly, is used to interpret the rest of the table.
!3 Fixture as Adapter
An object may be associated with a ''!-DoFixture-!'' (by calling the method ''setSystemUnderTest(Object)'' or through the ''super()'' constructor). If there is no method in the ''!-DoFixture-!'' corresponding to an action, ''!-DoFixture-!'' tries to call that method on the ''!-SystemUnderTest-!'' object instead (if it's been defined). (This approach is also used in [[''!-CalculateFixture-!''][.FitLibrary.UserGuide.FitLibraryByExample.CalculationRule]] and [[''!-SetUpFixture-!''][.FitLibraryUserGuide.SetUpFixture]].)

This means that a subclass of ''!-DoFixture-!'' is only needed as an adapter, when actions don't map directly onto methods of the ''!-SystemUnderTest-!'' object.
!3 Domain Objects
If an action corresponds to a property, the value of that property is returned. The value may be an ''Object''.

Because some ''Object''s are auto-wrapped with ''!-DoFixture-!'', it's possible to access and test domain objects directly, without the need to write fixtures.
!3 Tests without Fixture
Because of auto-wrapping and Domain objects, it's possible to use Fit for testing without the need to write any fixtures at all (inspired by [[''Naked Objects''][http://www.nakedobjects.org]]).My original aim in introducing these facilities was to enable the use of Fit in teaching beginner programmers, but I found them generally useful.

This approach depends on two experimental special actions in ''!-DoFixture-!'':
 * A ''start'' special action creates an object of the specified class as the ''!-SystemUnderTest-!'' object. This can be an object of any class that has a public nullary constructor.
 * A ''calculate'' special action in ''!-DoFixture-!'' returns a ''!-CalculateFixture-!'' that refers to the ''!-SystemUnderTest-!'' object of the ''!-DoFixture-!''. This means that the rest of the table is interpreted by that ''!-CalculateFixture-!'', without needing a subclass of that fixture.

This may need more work to make it general enough...

Here's a trivial example:

|!-fitlibrary.DoFixture-!|
|start|java.awt.Rectangle|

|check|''x''|0|
|check|''y''|0|

|set location|100||200|
|check|''x''|100|
|check|''y''|200|
 * ''location'' gives a copy of the ''Point'' of the (x,y) position of the Rectangle:
|location|
|''move''|12||14|
|check|''x''|12|
|check|''y''|14|
 * The original location is unchanged
|check|''x''|100|
|check|''y''|200|

|''set size''|20||30|
|check|''width''|20|
|check|''height''|30|