Pass the Salesforce Developers PDII Questions and answers with CertsForce

To communicate a property change up a containment hierarchy in Lightning Web Components (LWC), the child component should dispatch a custom event with the detail of the change. The parent component listens for this event and handles it accordingly.

Option A is the correct method because it creates a new custom event with the detail property containing the new value of passthrough. This event is then dispatched, and the parent component can listen for this event to handle the updated value.

Options B, C, and D are incorrect because they either don't pass any data with the event or they don't use the detail object which is the standard way to pass data with custom events in LWC.

For the unit test to create the controller extension, the correct setup is to instantiate a new ApexPages.StandardController with the Account record and then use it to instantiate the AccountControllerExt. This sets up the controller extension with the context of the provided Account record.

Using the @testSetup annotation to define a method that creates test data before the tests run can significantly speed up test execution by reducing the setup time for each test method in the class. This method runs once before any test method in the class and can be used by all test methods.

The System.runAs() method is used in test classes to enforce record sharing. This method allows you to write test methods that change user contexts to ensure that the proper record sharing is enforced. References:

Understanding the runAs Method

Test.setCurrentPage(Page.MyTestPage) is used to set the context to a Visualforce page in tests, allowing you to simulate a page request in a test method.

To retrieve the Show_Help__c preference for the current user from a hierarchy custom setting, the getInstance() method should be used. This method retrieves the custom setting data for the user or the organization default if no user-specific setting is found.

When faced with performance issues in a Lightning Web Component (LWC) due to SOQL query load times, the optimal approach is often to improve the query's selectivity. This can be achieved by using a selective SOQL query with a custom index. Salesforce can create custom indexes to improve the performance of queries that cannot be optimized through standard indexing. When a query is selective, it can efficiently retrieve records from the database using the index, thus reducing the query execution time and speeding up the component's performance when filters are changed. The other options (returning all records, using SOSL, or client-side caching) do not directly address the root cause of the performance issue, which is the need for a more efficient database operation.

Custom metadata types are ideal for storing configuration data such as shipping rates by region. These rates can be deployed to production without additional steps and can be queried in Apex, allowing the calculations to work immediately post-deployment.

To ensure that the test class for a search functionality in Salesforce runs successfully, the developer should use the Test.setFixedSearchResults() method. This allows the test to specify the records that are returned by the search, ensuring that the search behavior is predictable and that the assertion can be properly evaluated.

Custom labels are used for translating text strings in Salesforce that need to be presented in multiple languages. They support translations and can be referenced in Aura components, Visualforce pages, and Apex code.