What type of testing does Appian use for validating expressions?

The type of testing that Appian uses for validating expressions is specifically termed Expression Rule Testing. This process involves testing the logic and calculations found within expression rules to ensure they are working as intended. Expression rules in Appian are reusable components that execute specific calculations or logic based on input parameters.

By focusing on Expression Rule Testing, developers can validate the functionality and output of these rules in isolation from the rest of the application. This helps to confirm that the expressions return the correct results and handle edge cases effectively. Testing expressions in this way can identify errors before they propagate through the application, thereby maintaining the integrity of the overall system.

This approach differs from other types of testing mentioned in the options. For instance, Automated Functional Testing refers to broader application testing to ensure features work as expected, and Unit Testing typically focuses on testing individual units of code, not specifically targeting expression rules. Integration Testing is aimed at ensuring that different parts of the application work well together, rather than focusing on the internal logic of expression rules. Therefore, Expression Rule Testing is the most accurate description of the testing Appian uses for its expression validations.