Try this one:

DECLARE @a nvarchar(max)

SELECT @a = ISNULL(@A,'') + OBJECT_DEFINITION(object_id) + '

GO

' FROM sys.procedures

SELECT CAST(@A AS XML)

Explanation:

1. Use OBJECT_DEFINITION to get the full script of the object in nvarchar(max)

2. Use the per row assignment to @a to add each object_definition to the variable.

3. Cast the result to XML and switch to Grid Mode, to avoid the result being cut off at x chars.