Test Coverage

Definitions

1. A metric — typically expressed as a percentage — that measures how much of a codebase's lines, branches, functions, or statements are exercised by the test suite. Tools like Istanbul/nyc, JaCoCo, and coverage.py instrument code to track which paths are hit during test execution.

   In plain English: A measurement of how much of the code is actually tested, usually shown as a percentage.

   Example: "Our test coverage is 87% by line but only 62% by branch — we're missing a lot of error-handling paths."

Related Terms

• Unit Test
• Integration Test
• Code Coverage
• Flaky Test
• Regression Test
• Suite
• Test Runner
• Test Suite
• Visual Regression Test
• Automated Testing
• Code Testing Culture
• Testing Standard