Top 15 Code Coverage Tools

Code coverage measures the percentage of code that an automated test can cover. It simply checks which statement of a code has executed at the test run time, and which statement can’t. It’s a type of white-box testing.

A code coverage tool gathers information about the running test, analyzes them, and generates coverage reports. In this way, it increases the code quality and reliability.

What are Code Coverage tools?

A code coverage tool is used for code coverage measurement. 

The code coverage testing tools help remove critical and unidentified bugs from the early stage of development – unit testing. Also, it removes the dead and repetitive codes from software. They provide developers with insights into which parts of their code are covered by test cases and which parts are not. The main purpose of code coverage tools is to help assess the effectiveness of the testing 

In this way, they improve the health, standard of your code and increase productivity. Thus they increase customer satisfaction. That’s why you need these tools.

How do Code Coverage tools work?

Code coverage tools typically work by instrumenting the code or by analyzing the code and its execution. They collect data and generate reports that show the percentage of code that was executed during the tests.

• First, you have to run and execute your tests. Then these tools calculate the percentage of your executed codes of the tests. 
• Then they generate the coverage report. 
• If you have different types of tests like unit, integration, and end-to-end tests, then they create the report for all test types and combine them into a single file.

What are the different types of code coverage?

• Function coverage: It’s the number of functions that have been called.
• Statement coverage: The number of the statements in a program you have executed.
• Branch coverage: The number of branches you execute from the control structure (if-else, while, do while, etc.)
• Condition coverage: The number of Boolean expressions you test in your code.
• Line coverage: The number of lines you test in your source code.

Top 15 Code Coverage tools in 2023 (Pros, Cons, Features)

1. JaCoCo

JaCoCo (Java Code Coverage) is an open-source code coverage free tool for Java applications. It provides detailed information about the code coverage achieved during testing, allowing developers to assess the effectiveness of their tests and identify improvement areas. 

Pros:

• Measures various code coverage metrics, including line coverage, branch coverage, instruction coverage, and cyclomatic complexity.
• Allows developers to configure coverage exclusions for specific classes, methods, or code blocks.
• Support testing for Java 7 and 8
• Integrates well with popular build systems and frameworks such as Ant, Maven, Gradle, and Eclipse

Cons: 

• No built-in, debug option for class compilation, and support for framework.

Features: Run unit test, provide visual report, integrates with different IDEs

Use case: Integration test, unit test

2. Cobertura

It’s the best code coverage tool for Java and integrates with Maven and Ant. It widely adopted by Java developers due to its simplicity, comprehensive reporting, and seamless integration with popular build systems and testing frameworks.

Pros: 

• Supports code coverage without source code.
• Integrates with testing frameworks, such as JUnit and TestNG, to collect coverage data during test execution
• Provides reports in HTML and XML format.
• Tracks historical coverage data, allowing developers to compare coverage trends over time.

Cons: 

• No built-in, debug option for class compilation, and support for framework.

Features: Of-line instrumentation, source code metrics, data management, report filtering, build tool integration, etc.

Use case: Unit test in Java

3. Clover

Clover is an open-source tool for Java and Groovy from Atlassian. It includes different IDE connectors and libraries. Clover is known for its  advanced analysis features, such as detecting complexity hotspots, identifying code duplication, and measuring cyclomatic complexity.

Pros

• Highly configurable HTML report, test optimization, distributed per-test coverage, automatic integration feature.
• Clover supports collaborative features, allowing teams to share and compare coverage data across different environments and configurations
• Supports various programming languages, making it suitable for projects with mixed-language environments.
•  It offers rich visualization and filtering options to analyze the coverage data.

Cons

• Need additional settings for some cases and build requirements for integration. 

Feature: Source code metrics, coverage metrics, etc.

Use case: Continuous integration, testing with JUnit, TestNG, and Spoke

4. SonarQube

It can’t measure the code coverage directly. SonarQube provides a centralized dashboard for measuring and managing code quality across multiple programming languages.

Pros:

• Integrates with code coverage tools, such as JaCoCo and Cobertura
• Integrates with various build systems, CI/CD pipelines, and version control systems, allowing for seamless integration into the development workflow. I
• Increase productivity and identify code redundancy
• Resize your application, remove code complexity, and help to understand.

Cons

• Expensive code maintenance and comparatively difficult administration management user interface.
• Comes with a set of predefined rules and quality gates that define the expected code quality standards. It

Features: Generic test data, test coverage format, test execution report, analysis with SonarScanner.

Use case: supports a wide range of programming languages, including Java, C/C++, C#, JavaScript, Python, PHP, and more. 

5. Jenkins

Jenkins is a code coverage open-source tool. Its aim is to provide a continuous integration so that you can deliver your software in a consistent manner. It’s written in Java.

Pros:

• You can know the test result of every commit without any delay.
• It can automate a test script after any modification on commit.
• Developers can focus only on the changed feature. There is no need to review the entire source code

Cons: None

 Features:

• Platform independent.
• Easy installation process and good community support.
• 1000+ plug-ins.

Use case: Integration testing

Integrate BrowserStack Automate with Jenkins

6. Xcode

This software develops apps for Apple platforms like iPhone, iPad, Apple TV, and watch. Xcode seamlessly integrates with testing frameworks such as XCTest for unit testing and XCUITest for UI testing. It simplifies the process of measuring code coverage within the Xcode IDE itself. 

Pros:

• Supports profiling and heap management.
• Measures the coverage achieved by unit tests and UI tests written in languages such as Swift and Objective-C
• Displays the coverage information alongside test results, making it easy to analyze coverage alongside test outcomes.
• Provide a large developer community and customers.

Cons:

• Create apps for only Apple OS.
• Supports an outdated programming language Objective C.

Features:

• It’s a complete package for developing, compiling, testing, and submitting an app on the Apple store.
• It provides a simulator, profiling tools, 3D compositions, build system, Swift package, and more.

Use case: Apple script

7. JUnit

JUnit itself is not a code coverage tool. There are several code coverage tools such as JaCoCo, Cobertura, and Emma that can be used in conjunction with JUnit to measure the coverage of your Java code. 

It  can be used for executing reparative automation tests. It uses both the traditional and latest methods for executing test scripts.

Pros:

• Can efficiently find bugs in the early stages of development.
• Integrate with other development tools – Maven, Eclipse.
• Create code coverage metrics to identify a missing test script.

Cons

• Utilizing advanced features and techniques in JUnit may require additional knowledge and expertise.
• Follows a hierarchical structure of test classes and methods, which can sometimes become complex to manage and navigate. 

Features:

• Provide Test Case class, annotations, and assertions.
• Provide test driven methodology, test suite and test fixtures.

Use case: Unit testing, regression testing, performance testing, cross-browser testing, etc.

8. Gradle

Gradle is not a code coverage tool but a build automation software. It can be used in conjunction with code coverage plugins or tools to generate code coverage reports as part of the build process. These plugins integrate with Gradle to instrument the code, track its execution during tests, and generate coverage reports based on the collected data. 

It supports different languages like Java, Scala, Groovy, etc. Also, supports building, testing, and deployment for multiple platforms. 

Pros: 

• Can resolve all the issues of other build tools and give a high-speed performance.
• It can customize multiple projects with multiple technologies.

Cons:

• Gradle’s code coverage plugins often require additional configuration and setup which can be complex

Features:

• Support multi-project build
• Also, support ANT build project and Maven repositories
• Provide build scan and incremental builds.

Use case: Build scripts – build.gradle

9. JTest

It’s one of the code quality coverage tools for Java applications. It maintains Agile methodologies to develop and test your code.

Pros:

• Maintain code coverage target and smart test execution.
• Can find high-priority vulnerabilities and recommend fixing them.
• Validate your code’s reliability and security with the static analysis.

Features:

• Real-time CI/CD pipeline, testing feedback, code coverage and quality checking.
• Support JUnit test creation
• Check compliance for CWE, OWASP, etc.

Use case: Unit testing, security testing, test impact analysis, etc.

10. Visual Studio Code

It’s a free code editor, compiler, and one of the code coverage analysis tools that supports different languages – C#, visual basics, etc. It’s developed by Microsoft and supports the .NET framework. 

While VS Code itself does not include a built-in code coverage tool, there are extensions like Coverage Gutters available that can provide code coverage functionality.

Pros:

• Cross-platform, different language, multi-project, extensions, Git support, and more. 
• Allows to merge and export code coverage results

Features: In-built multi-language support, intelli-sense, repository, hierarchy structure, improvement instructions, etc.

Use case: Unit test, cross-browser testing, Selenium automation.

11. Emma

Emma is an open-source, free, code coverage tool for Java. It supports different coverage criteria, such as statement coverage, branch coverage, and method coverage.

Pros: 

• It’s a purely Java based, so, it doesn’t have any external library dependency.
• You don’t need to access to the source code
• Individual class file instrumentation is possible.

Features: Offline and on-fly instrumentation, different coverage type, etc.

Use case: Unit and regression testing

12. Istanbul

Istanbul is a code coverage tool for JavaScript. You can use it for JavaScript instrumentation. It helps to track the statement, line, branch, and function of code coverage

Pros:

• Support most of the popular JS testing frameworks.
• Generate a report adding a simple coverage flag.

Features: Babel plug-in, NYC command line interface, HTML output, etc.

Use case: Unit test, functional test

13. Coveralls

It’s a free, open source tool that works with CI server. It integrates with popular version control systems (VCS) such as Git and supports various programming languages and test frameworks. It can be used for projects written in languages like Python, Ruby, JavaScript, Java, and more

Pros: Free for public repos, good code coverage, and easy integration.

Features: Repos coverage statistics, repos overview, individual file coverage repos.

Use case: CI in Ruby

14. SonarCloud

It’s one of the code coverage analysis tools that provide cloud-based quality and security service for your codes.

Pros: Fast and scalable, strong code analysis, strong static code analysis.

Features:  

• 23 languages coverage including T-SQL, PLSQL.
• Provides thousands of rules to track critical bugs.

Use case: Cloud CI integration with Travis, Azure DevOps, etc.

15. OpenClover

OpenClover is a code coverage tool for Java and Groovy. It provides a robust instrumentation for code. It shows the skipped tests for a code and finds out the most risky area.

Pros: 

• Reduce test execution time
• Provide code coverage for individual test execution
• It helps to focus you on the important part of a code

Features: 

• Two types of code coverage – global and pre-test, 20+ built-in code metrics
• HTML current report, HTML historical report, tool and test framework integration, etc.

Use case: Unit tests

Code coverage tools based on Programming language

Criteria for selecting a code coverage tool

• Ease of use: An ideal code coverage tool is easy to handle. The tool doesn’t generate extra or complicated tasks at time of testing.
• Pricing: You should choose the free or low price tool for the test coverage based upon your budget. 
• Feature: You need to choose a tool having these features – instrumentation, coverage metrics, source code metrics, data management, historical reporting, CI server integrations, different language support, etc.
• Functionality: You can choose a tool that provides 80% code coverage. It’s the standard value of coverage.
• Reporting: A best coverage tool generates a clear report about which part of the code becomes tested and which part needs more testing. So, it helps the testers to identify the outstanding test cases. Also, it removes the redundant tests.

Which code coverage tool should you choose? 

• It’s important to evaluate your specific needs, such as programming language, integration capabilities, and desired coverage metrics, when choosing a code coverage tool. 
• You can choose a coverage tool based upon the programming language you’re using. 
•  If you choose to have straight forward reporting, choose Istanbul or may prefer HTML reports from Clover, OpenClover, etc.

Wrap Up

Once you’ve understood  the different types of code coverage tools, you can opt for BrowserStack that supports integration with different test coverage tools like – Junit, Jenkins, Gradle, CI/CD and more.

 With BrowserStack Test Management, never miss a beat on your testing activities. Get a high-level overview or drilled-down details of your test cases and test runs.

FAQs

1. Which is a code coverage tool?

A code coverage tool helps you to measure the amount of test cases successfully tested in a source code.

2. What are the 5 code coverage methods?

The 5 code coverage methods are- statement coverage, decision coverage, function coverage, line coverage, and condition coverage.