What is the difference between files and fileset option in the clover-setup task?

[Marek Parfianowicz]

The <clover-setup> has two similar tags:

• <files>
• <fileset>

In both of them we can specify inclusion/exclusion pattern for instrumentation.

What are the differencies?

[Marek Parfianowicz · Accepted solution]

The <files> is an Ant's PatternSet. It means that you do not specify any root directory, but only path fragments for inclusion/exclusion patterns.

The <fileset> is an Ant's DirSet. Therefore it has a "dir" attribute and uses a standard Ant's DirectoryScanner to find sources for inclusion/exclusion.

But there are more differencies.

Because of fact that <fileset> is a DirSet, it is being resolved by Ant at the time when it processes the <clover-setup> task configuration. It means that base directory specified in the "dir" attribute as well as source files to be included/excluded must be present at the time when the <clover-setup> task is called.

It has implication for instance in case when you use Clover and generate sources and want to exclude them. In such case you have to ensure that <clover-setup> is called after source generation (otherwise sources won't be put into Clover's exclusion list).

Alternatively, you could switch to the <files> PatternSet.

Because of fact that <files> is a PatternSet, it is being resolved by Clover at the time when it instrument sources, i.e. at the moment when the <javac> task (intercepted by Clover) is called.

It means that files do not have to be present at the time when <clover-setup> is called in order to be properly included/excluded.

And how paths defined in the <files> PatternSet are matched against sources?

Well, they're being matched against source roots passed to <javac>. So you shall define values of includes/excludes attributes as paths relative to the <javac srcdir="..."> attribute.

[Marek Parfianowicz]

There is one more difference between the <files> and the <fileset>. First one performs the same pattern matching on all source roots. Second one has the "dir" attribute, which you can use to restrict pattern matching to certain source roots.

Imagine a case in which you have "src" and "test" folders, both containing the "com.acme" package (among other packages) and that you want to exclude it from instrumentation.

<files><excludes name="com/acme/**"></files>

excludes "com.acme.*" from both the "src" and the "test" folders.

<fileset dir="test"><excludes name="com/acme/**"></fileset>

excludes "com.acme.*" from the "test" folder only.