improve-test-coverage

To fix missing unit test coverage, you diagnose uncovered paths using the project's coverage tooling, then add targeted tests, mock external dependencies, or refactor untestable code to close the gaps.

Test coverage drops when new code paths lack tests, and you restore it by analyzing coverage reports to identify exact missing branches and adding unit tests or mocks to meet existing thresholds.

To make untestable code testable for unit testing, you refactor the logic to isolate external dependencies and then apply mocking to exercise error branches and pure logic independently.

Yes, you need detailed coverage reports to diagnose missing error paths and branches, because they locate the weakest files and uncovered paths using the project's own coverage tooling.

Yes, you can scope coverage analysis and remediation to a specific file or package, and the process preserves existing coverage thresholds while working toward meeting or exceeding them.

Use mocking to improve test coverage when external dependencies block unit testing, and use refactoring when code structure is fundamentally untestable and prevents pure logic or error branch execution.