comprehensive test coverage

Ensure tests cover not only the happy path but also edge cases, error scenarios, and complete workflows. Many code reviews reveal gaps where only basic functionality is tested while important edge cases, exception handling, and integration scenarios are missing.

Key areas to address:

Add missing test scenarios: When implementing new functionality, include tests for all supported operations and variations. For example, if adding support for --to-earliest, also add tests for --to-latest and --to-datetime.

Cover edge cases and error conditions: Test boundary conditions, empty inputs, invalid parameters, and exception scenarios. Include tests for when external dependencies fail or return unexpected results.

Test complete workflows: Rather than testing individual components in isolation, add integration-style tests that verify end-to-end functionality works correctly.

Use randomized testing for consistency: For complex logic, consider adding tests that run multiple iterations with random inputs to ensure consistent behavior across different scenarios.

Verify exception handling: When code can throw exceptions, test both the success and failure paths to ensure proper error handling and recovery.

Example of comprehensive coverage:

@Test
public void testAlterShareGroupToLatestSuccess() {
    // Test the happy path
}

@Test  
public void testAlterShareGroupWithInvalidInput() {
    // Test error scenarios
}

@Test
public void testAlterShareGroupEndToEndWorkflow() {
    // Test complete integration workflow
}

@Test
public void testAlterShareGroupRandomizedInputs() {
    // Test with varied random inputs for consistency
}

This approach catches bugs early, improves code reliability, and provides confidence that the implementation handles real-world usage patterns correctly.