According to statistics, 80% of bugs originate in the early stages of development, but 90% only surface in a live environment. Most of these bugs occur in parts of the code that were never executed in any test case.
For most teams, test coverage is still just a statistic—a number read at the end of the report. In reality, it is one of the most critical quality indicators, clearly showing which parts of the system are safe and where the risks lie.
Why Running Tests Isn't Enough
During a development cycle, many modules are modified, new features are added, and some may become obsolete. Without accurate coverage data, the team has no visibility into the testing blind spots.
TestNavigator offers real help here: it measures test coverage at the bytecode level, precisely identifying which code pieces were executed during tests and which were not. The system immediately visualizes problematic areas through HeatMap and Code View modes, making it easy for developers and testers to pinpoint the modules, classes, or methods with the lowest coverage.
What Was Invisible Becomes Visible
The TestNavigator Code View page goes beyond simple charts; it operates at the code level. It makes it possible to see, line by line, which parts of the code were executed during tests and which were not.
This enables teams to strategically enhance their test suites by assigning new test cases to uncovered code areas, thereby gradually increasing reliability and reducing the occurrence of bugs.
The visual representation also aids immediate decision-making. For example, if the HeatMap turns deep red after introducing a new module, that indicates insufficient testing attention was given to the changes. This allows intervention during development—long before bug reports start appearing.
Data-Driven Testing Decisions
Traditionally, testers rely on intuition to decide which test cases to re-run. TestNavigator, however, leans on data:
- shows test coverage percentages for the entire system or even a single class,
- identifies code that has been modified but not yet tested,
- prioritizes test cases to ensure the most critical ones aren’t overlooked,
- and provides detailed statistics on the type of test cases contributing to increased coverage.
The software distinguishes between unchanged, modified, and newly written code, helping developers see exactly how much of their latest changes have actually been tested.
Test Coverage Is More Than Just a Number
Coverage metrics aren't ends in themselves. TestNavigator's analysis directly influences test case design and project risk management.
Identifying untested code helps eliminate redundant test runs and enables the team to focus on truly critical parts. This is especially important in large systems with thousands of test cases in a regression cycle, where time and resources are limited.
Thus, the tool doesn’t just measure—it also prioritizes, providing both developers and test managers a transparent overview of which areas require urgent attention.
Test Smarter
Software bugs often show up where least expected. The solution isn’t generating more test cases—but executing optimized testing. Identifying untested code segments is one of the most important steps in a modern development process.
TestNavigator not only shows what you've tested—but also highlights what you haven’t. That knowledge allows the development of truly reliable, scalable, and secure systems.
Based on Shaiful Chowdhury’s 2024 study