Create a new metric
CodeCover is delivered with four implemented coverage metrics:
- Statement coverage
- Branch coverage
- Loop coverage
- Strict condition coverage
If these metrics don't suite your needs, you can implement your own
metric.
This metric can use the data collected by the instrumented code in order
to provide coverage statistics.
Implementing the CoverageMetric interface
In order to create a new metric, you have to implement the
org.codecover.metrics.coverage.CoverageMetric
interface. This interface contains methods
to calculate the coverage for MAST nodes.
The abstract class
org.codecover.metrics.coverage.AbstractCoverageMetric
provides default implementations for many methods in the interface.
You still have to implement the getCoverageLocal() and
getHints() methods.
The getCoverageLocal() methods return the coverage for a
single MAST element. If your metric doesn't create coverage information
for a specific MAST element, you can return
CoverageResult.NULL in this overload.
The getHints() methods return additional coverage hints.
If you don't want to return additional coverage hints, you can return
noHints which is an empty
Set<CoverageHint>.
Creating a plugin
In order to create a plugin with your new metric, you have to create a
class implementing org.codecover.model.extensions.Plugin.
You can use org.codecover.model.extensions.AbstractPlugin
for an easier implementation.
In order to create a plugin, you have to put all necessary
.class files into a .jar file with a file
called codecover-plugin.xml which has the following
structure:
<plugin xmlns="http://www.codecover.org/xml/plugin-descriptor-1.0"
name="example.metric" version="4.2"
class="example.metric.MetricPlugin">
<depends name="org.codecover" version="0.1" />
</plugin>
Here it is assumed that your plugin class has the name
example.metric.MetricPlugin and you want to call your plugin
example.metric with the version number 4.2.
The plugin will require CodeCover with a plugin ABI version of
0.x with x >= 1.
Example
In order to compile the example you might have to adjust the path of the
codecover-core.jar in the build.xml file.
The example is an implementation of a method coverage. Only methods with at least one basic statement will be considered.
