I just saw that there is propositions to remove CodeMorph:

http://code.google.com/p/pharo/issues/detail?id=2902&q=CodeMorph&colspec=ID%20Type%20Status%20Summary%20Milestone%20Difficulty

So maybe the best fix will be to remove all the tests related ? :)

2010/10/1 Cyrille Delaunay <cy.delaunay@gmail.com>
In pharo 1.2, NewTextMorphTests>>#testFullMethodName raise an error. This error happen when calling:

   CodeMorph >> defaultStyledText
	| text attribute |
	text := self text.
	text addAttribute: ( self newTextColorAttribute: Color black ).
	^ text.

text is a string, and therefore it does not understand 'addAttribute'. The value return by 'text' depends on the value of the instance variable 'adapter'. adapter can have different values according the way we initialize the CodeMorph. One of them is:

  beFullMethodName 
	aspect := #selector.
	adapter := [:selector| target methodClass name , '.' , self selectorWithArguments ].  

The block return a String and I guess the right code should be 

    beFullMethodName 
	aspect := #selector.
	adapter := [:selector| (target methodClass name , '.' , self selectorWithArguments) asText ]

??.  

I opened an Issue: http://code.google.com/p/pharo/issues/detail?id=3031