HTTP Mock Lib

Appearance

Response Body ​

Configure the response body for your mocked HTTP calls.

Overview ​

HTTP Mock Lib supports three types of response bodies:

  • String - Raw string data
  • Object - Apex objects (automatically serialized to JSON)
  • Blob - Binary data

API ​

body(String) ​

Set a string response body.

apex
HttpMock body(String body)

Example:

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

body(Object) ​

Set an object response body. The object will be JSON-serialized automatically.

apex
HttpMock body(Object body)

Example:

apex
Map<String, Object> response = new Map<String, Object>{
  'id' => '123',
  'name' => 'John Doe',
  'email' => 'john@example.com'
};

new HttpMock()
  .whenGetOn('/api/users/123')
  .body(response)
  .statusCodeOk()
  .mock();

body(Blob) ​

Set a binary response body.

apex
HttpMock body(Blob body)

Example:

apex
Blob pdfData = Blob.valueOf('PDF content here');

new HttpMock()
  .whenGetOn('/api/documents/123')
  .body(pdfData)
  .contentTypePdf()
  .statusCodeOk()
  .mock();

Examples ​

JSON String Response ​

apex
new HttpMock()
  .whenGetOn('/api/v1/token')
  .body('{"access_token": "abc123", "expires_in": 3600}')
  .contentTypeJson()
  .statusCodeOk()
  .mock();

Map Response ​

apex
Map<String, String> tokenResponse = new Map<String, String>{
  'access_token' => 'abc123',
  'expires_in' => '3600'
};

new HttpMock()
  .whenGetOn('/api/v1/token')
  .body(tokenResponse)
  .statusCodeOk()
  .mock();

List Response ​

apex
List<Map<String, String>> users = new List<Map<String, String>>{
  new Map<String, String>{ 'id' => '1', 'name' => 'Alice' },
  new Map<String, String>{ 'id' => '2', 'name' => 'Bob' }
};

new HttpMock()
  .whenGetOn('/api/users')
  .body(users)
  .statusCodeOk()
  .mock();

Custom Class Response ​

apex
public class UserResponse {
  public String id;
  public String name;
  public String email;
}

UserResponse user = new UserResponse();
user.id = '123';
user.name = 'John Doe';
user.email = 'john@example.com';

new HttpMock()
  .whenGetOn('/api/users/123')
  .body(user)
  .statusCodeOk()
  .mock();

XML Response ​

apex
String xmlResponse = '<?xml version="1.0"?>' +
  '<user>' +
    '<id>123</id>' +
    '<name>John Doe</name>' +
  '</user>';

new HttpMock()
  .whenGetOn('/api/users/123')
  .body(xmlResponse)
  .contentTypeXml()
  .statusCodeOk()
  .mock();

Empty Response ​

For responses with no body (like DELETE operations):

apex
new HttpMock()
  .whenDeleteOn('/api/users/123')
  .statusCodeNoContent()
  .mock();
// No .body() call needed

Binary Response (PDF) ​

apex
Blob pdfContent = generatePdfContent();

new HttpMock()
  .whenGetOn('/api/reports/monthly.pdf')
  .body(pdfContent)
  .contentTypePdf()
  .header('Content-Disposition', 'attachment; filename="report.pdf"')
  .statusCodeOk()
  .mock();

Object Serialization ​

When using body(Object), HTTP Mock Lib uses JSON.serialize() to convert your object:

apex
// This code:
new HttpMock()
  .body(new Map<String, String>{ 'key' => 'value' })
  .mock();

// Is equivalent to:
new HttpMock()
  .body('{"key":"value"}')
  .mock();

Default Behavior ​

If you don't call .body(), the response body will be an empty string:

apex
new HttpMock()
  .whenGetOn('/api/ping')
  .statusCodeOk()
  .mock();
// Response body: ""

Best Practices ​

  1. Use Objects for Complex Data - For complex responses, use Maps or custom classes instead of building JSON strings

  2. Match Real Responses - Use response formats that match your actual API

  3. Set Appropriate Content-Type - Always set the correct content type for your response body

  4. Validate JSON - If using string bodies, ensure your JSON is valid

  5. Test Edge Cases - Mock empty responses, large responses, and malformed responses

Common Patterns ​

Paginated Response ​

apex
Map<String, Object> paginatedResponse = new Map<String, Object>{
  'data' => new List<Map<String, String>>{
    new Map<String, String>{ 'id' => '1' },
    new Map<String, String>{ 'id' => '2' }
  },
  'page' => 1,
  'total_pages' => 5,
  'total_count' => 50
};

new HttpMock()
  .whenGetOn('/api/users?page=1')
  .body(paginatedResponse)
  .statusCodeOk()
  .mock();

Error Response ​

apex
Map<String, Object> errorResponse = new Map<String, Object>{
  'error' => new Map<String, String>{
    'code' => 'INVALID_REQUEST',
    'message' => 'Email is required'
  }
};

new HttpMock()
  .whenPostOn('/api/users')
  .body(errorResponse)
  .statusCodeBadRequest()
  .mock();

See Also ​