[MSHARED-1045] MSHARED-1024 breaks binary backwards compatibility

[jira-importer]

Andrei Silviu Dragnea opened MSHARED-1045 and commented

#2 breaks binary backwards compatibility of interface MavenReport, because replacing org.codehaus.doxia.sink.Sink with org.apache.maven.doxia.sink.Sink changes the signature of method:

void generate( Sink sink, Locale locale ) throws MavenReportException;

So nothing compiled against version 3.0 of the maven-reporting-api works with 3.1.0 anymore.

I suggest either reverting this commit in a new release or updating the code in a backwards-compatible manner with two mutually recursive default implementations for both the old and new signature (this requires Java 8 support though):

 

@Deprecated
default void generate( org.codehaus.doxia.sink.Sink sink, Locale locale ) throws MavenReportException {
    generate((Sink) sink, locale);
}

default void generate( Sink sink, Locale locale ) throws MavenReportException {
    generate((org.codehaus.doxia.sink.Sink) sink, locale);
} 

The solution above can result in ClassCastExceptions though, because some org.apache.maven.doxia.sink.Sink maybe do not implement org.codehaus.doxia.sink. I do not know any way of safely evolving the type of an input parameter for a method.

---

Issue Links:

• MSHARED-1118 Restore binary compat for MavenReport (partially revert MSHARED-1024)
  ("is fixed by")
• MSHARED-1024 Replace deprecated code
  ("is caused by")

[jira-importer]

Michael Osipov commented

Do you have an explicit example which fails? Maven Reporting Impl still contains this method.

[jira-importer]

Andrei Silviu Dragnea commented

I have reproduced the bug here: https://github.com/andreisilviudragnea/maven-reporting-api-bug The details are in README.

[jira-importer]

Michael Osipov commented

Thanks, will take a look. But also consider that the used Sink has been deprecated more than 10 years ago.

[jira-importer]

Andrei Silviu Dragnea commented

I am just a user of the Maven Scoverage plugin which got broken by this update.

I wanted to make sure this change was not accidental, since the version update suggests it is a backwards compatible change (I do not know if Maven respects semver or not), even though it is not.

I researched the problem more and the only safe way of updating this is either increasing the major version or defining a new interface altogether. But maybe there are other solutions for deprecating a method of an interface that I am not aware of.

[jira-importer]

Michael Osipov commented

Please report upstream.