SF-PD2 Practice Test 14 — 15 Questions

Question 1

A developer must write a test class for an Apex service that performs an HTTP callout to an external REST API. The test cannot make real callouts. Which approach should be used to simulate the callout response?

Choose an answer to begin — your selection is scored in the full session.

Accepted Answer

Implement the HttpCalloutMock interface and register it with Test.setMock().. The correct approach is to implement the HttpCalloutMock interface and register it with Test.setMock(). This allows the test to simulate the external service response without making a real callout, ensuring the test is reliable and adheres to Salesforce's testing requirements. Other options do not prevent real callouts or provide a mock response.

Answer

Use Test.startTest() and Test.stopTest() to isolate the callout.

Answer

Wrap the callout in a try-catch block and assert that no exception is thrown.

Answer

Set the endpoint URL to a static resource containing the expected response.

Question 2

A developer is writing an Apex test class for a service that calls an external REST API using a Named Credential. The test must not make real callouts, and the developer wants to verify that the correct endpoint and body are sent. Which approach should the developer use?

Accepted Answer

Implement the HttpCalloutMock interface in a test class and register it with Test.setMock(HttpCalloutMock.class, new MockImpl()).. The HttpCalloutMock interface is the designated mechanism for simulating callouts in Apex tests. By implementing it and registering an instance with Test.setMock, the developer can intercept Http.send() calls, return a controlled response, and inspect the HttpRequest to confirm the endpoint and body. This keeps the test isolated, fast, and free of external dependencies, and it aligns with Salesforce best practices for testing callout logic.

Answer

Use Test.isRunningTest() inside the service class to conditionally skip the callout and return a hardcoded response.

Answer

Wrap the callout in Test.startTest() and Test.stopTest() to prevent the callout from executing during the test.

Answer

Set the endpoint in a Custom Setting and use a test-specific value that points to a local mock server.

Question 3

A developer is optimizing a Visualforce page that displays a large list of Opportunities with related OpportunityLineItems. The page currently uses a standard controller with an `<apex:pageBlockTable>` and a SOQL query in the controller that retrieves all Opportunities and their line items. The page loads slowly and sometimes hits governor limits. Which two strategies should the developer use to improve performance? (Choose two.)

Accepted Answer

Implement pagination using `StandardSetController` to limit the number of records displayed per page.. Implementing pagination with `StandardSetController` limits the number of records loaded and displayed, reducing view state and governor limit risks. Marking non-essential controller variables as `transient` reduces view state size, which directly improves page load time. Both strategies address the core performance issues of large data sets in Visualforce.

Answer

Use `@AuraEnabled` methods to retrieve data via Lightning Data Service instead of a Visualforce controller.

Answer

Move the SOQL query to a future method to run asynchronously.

Answer

Use `SOQL` with `FOR UPDATE` to lock records and prevent concurrent updates.

Question 4

A developer has built a Lightning Web Component that calls an Apex controller method to retrieve a list of Opportunities for a given Account. The SOQL query uses an indexed field on the Opportunity object, but the query still times out for Accounts with over 100,000 related Opportunities. The developer wants to improve performance by reducing the amount of data transferred and processed. Which approach should the developer take?

Accepted Answer

Implement pagination using a custom cursor or Keyset pagination with the Id field.. Keyset pagination, also known as seek pagination, uses an indexed column (such as Id) to retrieve the next page of results without scanning previous rows. This method is highly efficient for large datasets because it avoids the performance degradation of OFFSET and limits the number of rows returned per call. By fetching only a small batch, it reduces both data transfer and processing, alleviating timeouts.

Answer

Use SOQL OFFSET to paginate through the Opportunity records in chunks.

Answer

Increase the query timeout by setting a higher value in the Apex controller.

Answer

Use a SOQL query with a FOR UPDATE clause to lock the records and speed up retrieval.

Question 5

A developer is optimizing a complex Apex transaction that processes a large number of records. The transaction currently performs multiple SOQL queries and DML operations inside loops. Which two strategies should be used to improve performance and avoid governor limit errors? (Choose two.)

Accepted Answer

Collect records in a list and perform a single DML operation after the loop instead of DML inside the loop.. The two key strategies are to move SOQL queries outside of loops and to consolidate DML operations. These practices, known as bulkification, minimize database round trips and governor limit consumption. They are essential for processing large data volumes efficiently in Apex. The other options either do not address the root cause or are not valid optimizations.

Answer

Use @future annotation on the method to run the DML asynchronously and avoid limits.

Answer

Increase the heap size by using the Limits.getHeapSize() method to monitor and adjust.

Answer

Use Database.insert with the allOrNone parameter set to false to allow partial success and continue processing.

Question 6

A developer is building a Lightning Web Component that contains an iframe hosting an external web application. The external application needs to send a message back to the Lightning Web Component when a user completes a task. Which mechanism should the developer use to receive that message securely?

Accepted Answer

Add a window message event listener in the component and validate the event origin against the expected external domain before processing the payload.. Cross-origin communication with an embedded external application is handled through the browser's postMessage API. The component adds a window message listener and validates event.origin against the trusted domain before acting on the payload. Lightning Message Service, @api properties, and polling contentWindow cannot bridge the same-origin boundary that isolates the external iframe.

Answer

Register a Lightning Message Service message channel and subscribe to it from the component; the iframe publishes to the same channel.

Answer

Use the Lightning Web Component's @api property to bind directly to a variable exposed by the iframe's document object.

Answer

Poll the iframe element's contentWindow property on an interval and read a status variable set by the external application.

Question 7

A developer is building a service class that must call an external REST endpoint and then update a related record. The external callout occasionally exceeds the allowed response time. The developer wants the update to occur only when the callout succeeds, and wants the failure path to be handled cleanly without leaving partial state. Which approach best satisfies these requirements?

Accepted Answer

Perform the callout, and if it succeeds, perform the DML update; wrap the callout in a try-catch and handle the exception before any DML executes.. The platform forbids making a callout after DML has occurred in the same transaction, so the callout must complete first. Handling the callout in a try-catch and performing the update only after a successful response ensures no partial state exists when the external service times out or errors. The other approaches either violate the callout-after-DML restriction, rely on unreliable rollback behavior, or move the work to an asynchronous context that cannot meet the conditional synchronous requirement.

Answer

Perform the DML update first, then make the callout, so the record is saved even if the external system is slow to respond.

Answer

Wrap the callout and the DML update together inside a single try-catch, relying on the transaction rollback to undo the update if the callout fails.

Answer

Use a future method to perform both the callout and the DML update, since future methods run asynchronously and avoid callout-after-DML errors.

Question 8

A developer deploys metadata to a production org using the Salesforce CLI. The deployment succeeds, but a post-deployment validation script that relies on a newly created custom setting record fails because the record is missing. The developer confirms the custom setting metadata was included in the package. What is the most likely explanation?

Accepted Answer

Custom setting records are not deployable through Metadata API, so they must be inserted with Apex or the data loader after deployment.. Custom setting records are treated as data rather than metadata, so a deployment that includes the custom setting definition does not carry its records. The post-deploy script fails because it queries a record that was never inserted into production. The developer must load the record separately after the metadata deployment completes, typically through Anonymous Apex or the data loader.

Answer

The deployment ran with the --dry-run flag, which validates but does not commit custom setting records to the target org.

Answer

Custom setting records deploy only when the org has the Custom Settings license enabled on the target user's profile.

Answer

The post-deployment script ran before the custom setting metadata finished indexing, so the record existed but was not yet queryable.

Question 9

A developer is building a Lightning Web Component that must navigate the user to a new record's detail page after a successful Apex DML operation. Which module should the developer use to perform the navigation?

Accepted Answer

import { NavigationMixin } from 'lightning/navigation';. Lightning Web Components navigate using NavigationMixin from the lightning/navigation module. After a successful DML operation, the component can use NavigationMixin.Navigate with a standard__recordPage page reference to redirect the user. Other options either reference non-existent modules, bypass the Lightning navigation framework with a full page reload, or rely on custom events that are not part of the platform navigation API.

Answer

import { navigate } from 'lightning/platformNavigation';

Answer

Use the window.location.assign method with a relative URL.

Answer

Dispatch a custom event named 'navigate' that the parent component handles.

Question 10

A developer is building a custom REST API using Apex. The API must return a response with a specific HTTP status code and a JSON body that includes custom error details. Which approach should be used to construct the response?

Accepted Answer

Use RestContext.response to set the status code and body. To return a custom HTTP status code and a JSON body from an Apex REST method, you must use RestContext.response. This object provides access to the response and allows setting the statusCode and responseBody properties. Returning a Map or throwing an exception does not give control over the status code or the ability to include structured error details.

Answer

Use ApexPages.currentPage().getParameters() to set response details

Answer

Throw an ApexException with a custom message

Answer

Return a Map<String, Object> from the method

Question 11

A developer needs to display a read-only, formatted phone number on a Lightning record page. The value comes from a field on the record and should render consistently with Salesforce's standard phone formatting. Which base component should be used?

Accepted Answer

lightning-formatted-phone. lightning-formatted-phone is the base component specifically designed to render phone numbers with standard formatting and a clickable tel link. Other formatted components target different data types, and lightning-output-field depends on a record form context. For a standalone, consistently formatted phone display, the phone-specific component is the correct choice.

Answer

lightning-output-field

Answer

lightning-formatted-number

Answer

lightning-formatted-text

Question 12

A developer is building an Apex trigger on a high-volume custom object that must update a related child record whenever a parent record's Status__c changes. The trigger runs for both single-record UI edits and bulk API loads of 200 records. The developer wants to avoid a per-record SOQL query inside the trigger loop. Which approach is the most performant and scalable?

Accepted Answer

Move the child query outside the loop and use a Map keyed by the parent Id, then iterate the trigger records against that Map.. Collecting the related children in a single query before the loop and indexing them by parent Id in a Map eliminates per-record SOQL, keeping the trigger within governor limits and bulk-safe. This pattern is the standard bulkification technique for parent-to-child updates and scales correctly for both single-record and 200-record API transactions.

Answer

Rely on a formula field on the child that references the parent's Status__c so no query is required in the trigger.

Answer

Use Database.query() inside the loop with a dynamically built WHERE clause for each parent record.

Answer

Add a SOQL query inside the loop that filters on the current record's Id to fetch the matching child.

Question 13

A developer is creating a Lightning Web Component that needs to display a toast message when a record is saved successfully. The developer imports ShowToastEvent from lightning/platformShowToastEvent. Which code correctly dispatches a success toast with the title 'Saved' and message 'Record saved successfully'?

Accepted Answer

this.dispatchEvent(new ShowToastEvent({ title: 'Saved', message: 'Record saved successfully', variant: 'success' }));. The correct code creates a new ShowToastEvent with an object containing title, message, and variant set to 'success', then dispatches it using this.dispatchEvent. This displays a success toast. The other options either use incorrect syntax, omit the variant, or attempt to call a non-existent static method.

Answer

ShowToastEvent.dispatch(this, { title: 'Saved', message: 'Record saved successfully', variant: 'success' });

Answer

this.dispatchEvent(new ShowToastEvent({ title: 'Saved', message: 'Record saved successfully' }));

Answer

this.dispatchEvent(new ShowToastEvent('Saved', 'Record saved successfully', 'success'));

Question 14

A developer is writing a unit test for a service class that performs a callout to an external REST endpoint. The test needs to verify that the class correctly parses a JSON response and updates a record. Which approach should the developer take to simulate the callout response in the test?

Accepted Answer

Implement the HttpCalloutMock interface and use Test.setMock(HttpCalloutMock.class, new MyMock());. The correct approach is to implement the HttpCalloutMock interface and register it with Test.setMock. This is the standard Salesforce pattern for simulating callouts in unit tests. It allows the developer to return a controlled response, ensuring the test focuses on the parsing and update logic without making real HTTP requests. The other options either do not simulate callouts or require undesirable changes to production code.

Answer

Use the @TestVisible annotation to inject a mock response into the service class.

Answer

Use Test.startTest() and Test.stopTest() around the callout to simulate the response.

Answer

Replace the callout with a hardcoded response using a static variable in the service class.

Question 15

A developer is designing a solution to process large volumes of incoming JSON data from an external system. The data must be transformed and loaded into multiple related custom objects. The processing must handle up to 1 million records per day and be resilient to failures. Which combination of features should the developer use to meet these requirements?

Accepted Answer

Use a Scheduled Apex job that invokes a Batch Apex class to process the data, with Database.Stateful to maintain state across batches.. Batch Apex is the optimal solution for processing large data volumes. It breaks the data into chunks, respects governor limits, and can maintain state with Database.Stateful. Scheduling the batch ensures daily processing. Other options either have scalability limits (Queueable, Flow) or are not designed for bulk data (Platform Events). The developer should also consider using Database.AllowsCallouts if needed.

Answer

Use Platform Events to publish each record and an Apex trigger to process them asynchronously.

Answer

Use a Flow with a Loop element to process each record and an Apex Action to perform DML operations.

Answer

Use a Queueable Apex job that chains itself to process records in chunks, with a final job to update related objects.