This repository aims to be a contribution to the Cobertura project. Current code is an MVP - minimum viable product to test if there is interest on Cobertura community for further development of some features and changes we introduce.

Our objectives

• tests should run once. Due to original Cobertura design, users were forced to run instrumentation and tests immediately, and later run tests again to see if something was broken.
• expose more data. Ex.: expose coverage thresholds and coverage data on reports, allow to build custom metrics. Serialize data in a readable format.
• provide a report where all metrics, thresholds and sourcelines are stored. New reports in different formats can be created from it without need to access the code again.
• decouple from Ant and provide a DSL to set parameters, run code instrumentation and provide programatic access to results
• provide means to add new metrics
• provide means to support multiple JVM languages

Do we break compatibility?

We want to keep this code backwards compatible. Original xml and html reports were not removed and old ant tasks can still be used. From the DSL we currently use another xml report format, and inclusion/exclusion ant-like patterns (ex.: "**/A.class") are not properly handled.

Arguments args =
    	         new Arguments().setBaseDirectory(origClassesDir.getAbsolutePath())
			.setDataFile("cobertura.ser")
			.setDestinationFile(intrumentedCodeDestDir.getAbsolutePath())
			.setEncoding("UTF-8");
Cobertura cobertura = new Cobertura(args).instrumentCode();
//run tests
cobertura.report().export(new XmlReportFormatStrategy());

When using Cobertura, we

• compile code to get .class files;
• instrument code; touch the bytecode, so that each accessed line is reported;
• run tests using instrumented bytecode which will hit ProjectData to store coverage data;
• aggregate collected data according to the JVM language it belongs to, since a source file may be translated to multiple .class files at non-Java JVM languages. We use an IReportBuilderStrategy implementations for this. Aggregated data is presented in a GenericReport object. This contains all coverage metrics and all source files lines. This way, once built, we no longer require source code to produce different reports.
• expose aggregated data from a GenericReport in different formats by implementing an IReportFormatStrategy interface.

Compile the code and run tests are requirements, not Cobertura's responsibility.

New metrics can be defined implementing ICustomMetric interface.

• we benefit from git and Maven tools.
• a DSL was created. Arguments can be set and results can accessed programatically.
• code instrumentation, tests and report building phases were decoupled. User is no longer forced to run tests twice. Just needs to run code instrumentation, then run the tests, and build coverage reports after that.
• project data information can be aggregated to build reports for other JVM languages
• an interface (ICustomMetric) for custom metrics was created. Implementations are loaded by reflection and automatically display on reports.
• a GenericReport is created.
• xml, html and threshold violations report strategies were implemented.
• for xml reports we use SimpleXML
• for html reports we introduced jatl

• review parameters Cobertura accepts. See how to deal with classes inclusion/exclusion when receiving Ant like patterns (ex.: "**/A.class")
• allow to assign a name to a project (currently a hash is calculated, based on project files)
• handle war/jar/ear files instrumentation
• create IReportBuilderStrategy implementations for other JVM languages

Contributions are welcome! You should be able to start working on this after cloning the repo and importing the Maven project to your IDE. You'll find the pom.xml file at cobertura_git/cobertura

See Cobertura "COPYRIGHT" file

Cobertura is free software. Most of it is licensed under the GNU GPL, and you can redistribute it and/or modify it under the terms of the GNU General Public License as published by the Free Software Foundation; either version 2 of the License, or (at your option) any later version. Please review the file COPYING included in this distribution for further details.

Parts of Cobertura are licensed under the Apache Software License, Version 1.1.

Cobertura is distributed in the hope that it will be useful, but WITHOUT ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License for more details.