jacoco/jacoco
Jacoco
JaCoCo is a Java code coverage tool and bytecode instrumenter that measures which parts of source code are executed during tests. It functions as a runtime agent to monitor application execution on the fly or as a library for offline bytecode instrumentation, allowing it to capture execution data in environments where runtime agents are restricted.
The project distinguishes itself by providing both dynamic and static instrumentation paths to track execution. It includes a runtime agent for on-the-fly monitoring and the ability to modify compiled class files before execution. It further enables the retrieval of execution metrics from running processes via remote network connections without interrupting the active application.
The system calculates quantitative coverage metrics across instructions, branches, lines, methods, and classes, alongside cyclomatic complexity measurements. It provides capabilities for merging data from multiple test runs, enforcing coverage thresholds within CI/CD quality gates, and generating reports that map executed bytecode back to source code. Visual integration is available for displaying these results directly within code editors.
The tool integrates with build automation systems and command line interfaces to automate data collection and report generation.
