Add an example for mocking non-default module export class (#9883)

CHANGELOG.md

@@ -19,6 +19,8 @@
 
 ### Chore & Maintenance
 
+- `[docs]` Add an example for mocking non-default export class
+
 ### Performance
 
 - `[jest-resolve]` Update `resolve` to a version using native `realpath`, which is faster than the default JS implementation ([#9872](https://github.com/facebook/jest/pull/9872))

docs/Es6ClassMocks.md

@@ -262,6 +262,22 @@ jest.mock('./sound-player', () => {
 
 This will let us inspect usage of our mocked class, using `SoundPlayer.mock.calls`: `expect(SoundPlayer).toHaveBeenCalled();` or near-equivalent: `expect(SoundPlayer.mock.calls.length).toEqual(1);`
 
+### Mocking non default class exports
+
+If the class is **not** the default export from the module then you need to return an object with the key that is the same as the class export name.
+
+```javascript
+import {SoundPlayer} from './sound-player';
+jest.mock('./sound-player', () => {
+  // Works and lets you check for constructor calls:
+  return {
+    SoundPlayer: jest.fn().mockImplementation(() => {
+      return {playSoundFile: () => {}};
+    }),
+  };
+});
+```
+
 ### Spying on methods of our class
 
 Our mocked class will need to provide any member functions (`playSoundFile` in the example) that will be called during our tests, or else we'll get an error for calling a function that doesn't exist. But we'll probably want to also spy on calls to those methods, to ensure that they were called with the expected parameters.