Tips for Increasing the Apex Code and Coverage for all Lines in Salesforce

 To increase the code coverage and understanding why certain lines of code remain uncovered during unit tests, here are the highlights scenarios where specific code paths, such as those within loops, conditionals, exception handlers, or batch processes, are not executed during tests, leading to incomplete coverage.

Key Insights and Best Practices

1. Understanding Code Coverage Calculation:

   • Code coverage measures the percentage of executable lines of code executed during tests.

   • Only executable lines are counted; comments, blank lines, and certain statements like System.debug() are excluded.​

2. Writing Effective Unit Tests:

   • Focus on testing the logic and behavior of the code by designing input data that ensures all code paths are executed.

   • Use assertions to verify that the code behaves as expected.​

3. Common Scenarios Affecting Coverage:

   • Control Structures: Ensure that both branches of if/else statements are tested by providing different inputs.

   • Loops: Populate collections to ensure loops iterate and execute their bodies.

   • Exception Handlers: Simulate exceptions in tests to cover catch blocks.

   • Batch Apex: Use Test.startTest() and Test.stopTest() to execute batch jobs within tests.​

4. Improving Coverage:

   • Write unit tests for uncovered code paths.

   • Refactor complex code to simplify testing.

   • Use tools like Test.startTest() and Test.stopTest() to manage governor limits and asynchronous operations.​

To increase code coverage and ensure all lines are tested:​

• Design Comprehensive Unit Tests: Create tests that cover all possible code paths, including different branches of conditionals and iterations of loops.

• Use Assertions: Verify that the code behaves as expected under various conditions.

• Simulate Exceptions: Test exception handling by simulating errors in your tests.

• Manage Asynchronous Operations: Use Test.startTest() and Test.stopTest() to handle asynchronous operations and governor limits effectively.​

By following these practices, you can achieve higher code coverage and ensure your Salesforce applications are robust and reliable.​