#24 TestCase should:raise: methods can improve error reporting

[Tim Mackinnon]

The #should:raise style methods don't give very good
error messages. They should report the Error they
recieved as in the following (the last method has all
the magic)

should: aBlock raise: anExceptionalEvent
self should: aBlock raise: anExceptionalEvent
description: ''

should: aBlock raise: anErrorClass description:
aStringDescription
^self should: aBlock raise: anErrorClass matching:
[:ignored| true ] description: aStringDescription

should: aBlock raise: anErrorClass matching:
aBlockForException
^self should: aBlock raise: anErrorClass matching:
aBlockForException description: ''

should: aBlock raise: anErrorClass matching:
aBlockForException description: aStringDescription
| formattedDescription raised |

aStringDescription isEmpty 
    ifTrue: \[formattedDescription := ''\]
    ifFalse: \[formattedDescription := ' \(' ,

aStringDescription , ')'].

raised := false.

\[\[aBlock value\] sunitOn: anErrorClass
    do: 
        \[:ex | 
        raised := true.
        \(aBlockForException value: ex\) ifTrue: \[^true\].
        self assert: false
            description: 'Raised \#' , anErrorClass name , ' but

failed to match '
, aBlockForException printString,
formattedDescription ]]
sunitOn: TestResult error
do:
[:ex |
raised
ifTrue: [ex signal]
ifFalse:
[self assert: false
description: 'Should raise: #' , anErrorClass
name , ' but was: #' , ex class name
, formattedDescription]].

self assert: false description: 'Should raise: \#' ,

anErrorClass name , formattedDescription