HTTP Mock Lib

Appearance

HTTP Methods ​

Mock different HTTP methods for your endpoints.

Supported Methods ​

HTTP Mock Lib supports all standard HTTP methods:

  • GET - Retrieve data
  • POST - Create resources
  • PUT - Update/replace resources
  • PATCH - Partially update resources
  • DELETE - Remove resources
  • HEAD - Get headers only
  • TRACE - Debug/diagnostic method

API ​

whenGetOn() ​

Mock a GET request.

apex
HttpMock whenGetOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenGetOn('/api/v1/users/123')
  .body('{"id": "123", "name": "John"}')
  .statusCodeOk()
  .mock();

whenPostOn() ​

Mock a POST request.

apex
HttpMock whenPostOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenPostOn('/api/v1/users')
  .body('{"id": "456", "created": true}')
  .statusCodeCreated()
  .mock();

whenPutOn() ​

Mock a PUT request.

apex
HttpMock whenPutOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenPutOn('/api/v1/users/123')
  .body('{"id": "123", "updated": true}')
  .statusCodeOk()
  .mock();

whenPatchOn() ​

Mock a PATCH request.

apex
HttpMock whenPatchOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenPatchOn('/api/v1/users/123')
  .body('{"updated_field": "new_value"}')
  .statusCodeOk()
  .mock();

whenDeleteOn() ​

Mock a DELETE request.

apex
HttpMock whenDeleteOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenDeleteOn('/api/v1/users/123')
  .statusCodeNoContent()
  .mock();

whenHeadOn() ​

Mock a HEAD request.

apex
HttpMock whenHeadOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenHeadOn('/api/v1/users/123')
  .header('Content-Length', '1234')
  .statusCodeOk()
  .mock();

whenTraceOn() ​

Mock a TRACE request.

apex
HttpMock whenTraceOn(String endpointToMock)

Example:

apex
new HttpMock()
  .whenTraceOn('/api/v1/debug')
  .body('TRACE /api/v1/debug HTTP/1.1')
  .statusCodeOk()
  .mock();

Multiple Methods ​

You can mock multiple HTTP methods in a single test:

apex
@IsTest
static void testCrudOperations() {
  new HttpMock()
    // Create
    .whenPostOn('/api/v1/users')
      .body('{"id": "123"}')
      .statusCodeCreated()
    // Read
    .whenGetOn('/api/v1/users/123')
      .body('{"id": "123", "name": "John"}')
      .statusCodeOk()
    // Update
    .whenPutOn('/api/v1/users/123')
      .body('{"updated": true}')
      .statusCodeOk()
    // Delete
    .whenDeleteOn('/api/v1/users/123')
      .statusCodeNoContent()
    .mock();

  Test.startTest();
  // Your CRUD operations here
  Test.stopTest();
}

Endpoint Matching ​

The endpoint parameter should match the path used in your callout:

apex
// If your code does:
Http http = new Http();
HttpRequest req = new HttpRequest();
req.setEndpoint('https://api.example.com/v1/users');

// Then mock like this:
new HttpMock()
  .whenGetOn('/v1/users')  // ✅ Correct - matches path
  .mock();

// Not like this:
new HttpMock()
  .whenGetOn('https://api.example.com/v1/users')  // ❌ Wrong - includes domain
  .mock();

Best Practices ​

  1. Use Full Paths - Include API version in the path: /api/v1/users instead of /users

  2. Match HTTP Semantics - Use the correct method for the operation:

    • GET for retrieval
    • POST for creation
    • PUT for full updates
    • PATCH for partial updates
    • DELETE for removal

  3. Test All Methods - If your service uses multiple HTTP methods, test them all

  4. RESTful Patterns - Follow REST conventions in your mocks to match real APIs

See Also ​