[ 
http://jira.codehaus.org/browse/MNG-2205?page=com.atlassian.jira.plugin.system.issuetabpanels:comment-tabpanel&focusedCommentId=146158#action_146158
 ] 

Roman Kalukiewicz commented on MNG-2205:
----------------------------------------

There is another very important reason why provided dependencies should be 
transitive. This reason is tests.

If you have some class that needs (lets say) servlet-api and servlet-api is 
provided, then you cannot use this class in another project, because when you 
write test, you are not able to instantiate your original class because it 
imports {{javax.servlet.*}} that is not available.

You also cannot extend any created servlet class in any different project, 
because it will not compile if {{Serlvet}} interface is not available on 
classpath. 
This is similar to the note you have just under the table at 
http://maven.apache.org/guides/introduction/introduction-to-dependency-mechanism.html#Dependency_Scope

I believe that the most typical situation is to scope servlet-api as provided 
and it shows, that it doesn't work as it should.

> "provided" scope dependencies must be transitive
> ------------------------------------------------
>
>                 Key: MNG-2205
>                 URL: http://jira.codehaus.org/browse/MNG-2205
>             Project: Maven 2
>          Issue Type: Bug
>          Components: Dependencies
>            Reporter: David Boden
>            Priority: Critical
>             Fix For: 3.0
>
>
> A provided scope dependency can also be thought of as "compile-only".
> Project A requires Sybase JConnect on the runtime classpath. Project A 
> declares a "provided" dependency on Sybase JConnect.
> Project B depends upon Project A. Project B declares a "compile" dependency 
> on Project A.
> Project C depends upon Project B. Project C declares a "compile" dependency 
> on Project B.
> C
> | - compile dependency
> B
> | - compile dependency
> A
> | - provided dependency
> Sybase JConnect
> So, does Project C transitively depend on Sybase JConnect. Yes, of course! 
> The "provided" dependency needs to be transitive.
> Ultimately, when Project C gets deployed, Sybase JConnect needs to be 
> somewhere on the runtime classpath in order for the application to function. 
> It's valid for Project C to assume that Sybase JConnect is available and use 
> JDBC all over the Project C code. Project C is safe to do this because it can 
> happily deduce that Sybase JConnect will be there in the runtime environment 
> because Project A NEEDS IT.
> I've got Use Cases all over my aggregated build which make it absolutely 
> critical and common sense that provided scope dependencies are transitive. 
> For the (very rare) odd case where you don't want to inherit provided 
> dependencies, you can <exclude/> them.

-- 
This message is automatically generated by JIRA.
-
If you think it was sent incorrectly contact one of the administrators: 
http://jira.codehaus.org/secure/Administrators.jspa
-
For more information on JIRA, see: http://www.atlassian.com/software/jira

        

Reply via email to