Branch coverage
Branch coverage is a test coverage metric measuring the proportion of a program’s control-flow branches executed by tests.
Unit Testing Principles, Practices, and Patterns
Branch coverage is a test coverage measure indicating which conditional branches in code are executed by tests.
- How it is used
- Uses executed conditional paths to assess test-suite completeness while warning against treating coverage as a quality score.
- How deep it goes
- Defines the ratio, demonstrates two paths, and explains limits involving assertions, external libraries, and imposed thresholds.
- Examples
- Uses an IsStringLong method, a short-string test, a two-path graph, and a 50% branch-coverage result.
- What you can do after
- Evaluate test-suite completeness, investigate low coverage, and balance coverage benefits against maintenance costs.
Read how Unit Testing Principles, Practices, and Patterns explains branch coverage →
100 Java Mistakes and How to Avoid Them
Branch coverage is the fraction of control-flow branches exercised by a test suite.
- How it is used
- Uses test reports to reveal unexercised control-flow alternatives that line or instruction coverage can conceal.
- How deep it goes
- Explains missing branches through an infinite-loop example and testing guidance, but stops short of coverage-tool configuration.
- Examples
- Uses a hasPercentD loop with inputs such as "%%%%" and "%%d%%%d" to illustrate branch-sensitive tests.
- What you can do after
- Diagnose/debug with it by locating untested loop branches and adding tests for zero, single, and repeated iterations.
Read how 100 Java Mistakes and How to Avoid Them explains branch coverage →
Practices of the Python Pro
Branch coverage is a test coverage metric measuring which branches of a program's control flow have been executed by tests.
- How it is used
- Guides tests toward exercising alternative execution paths and exposing overlooked edge cases.
- How deep it goes
- Defines execution-path coverage and its limitation, then points to tooling without developing measurement internals.
- Examples
- Uses a Python function with type checking, a loop, a length condition, an early return, and a fallback return.
- What you can do after
- Apply it via the Coverage package to inspect branch coverage metrics for tests.
Read how Practices of the Python Pro explains branch coverage →
Related concepts
- code coveragekind of · Code coverage measures the extent to which a test suite exercises a program’s code elements, execution paths, or behaviors.
- conditional logicuses · Conditional logic is a programming technique that selects execution paths, actions, or result values according to evaluated conditions.
- accuracycontrasts with · Accuracy is the degree to which an output, prediction, or measurement agrees with a correct or reference outcome under a specified criterion.
- evaluation suitemeasured by · An evaluation suite is an organized collection of tests, cases, or tasks used to assess a system against specified behaviors or criteria.
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