Update @salesforce/apex/* imports to return jest.fn()

packages/@lwc/jest-preset/README.md

@@ -110,6 +110,36 @@ Then, create a new test file in `__tests__` that follows the naming convention `
 
 Now you can write and run the Jest tests!
 
+#### @Salesforce/apex/ Method Mocks
+
+Imports of `@Salesforce/apex/*` automatically resolve to `jest.fn()`, these can be optionally overwritten.
+
+```js
+import apexMethod from '@Salesforce/apex/apexClass.apexMethod';
+
+it('test apex cal', async () => {
+    apexMethod.mockResolvedValue({ foo: 'bar' });
+});
+```
+
+Optional set function for method manually
+
+```js
+import apexMethod from '@Salesforce/apex/apexClass.apexMethod';
+
+jest.mock(
+    '@salesforce/apex/apexClass.apexMethod',
+    () => ({
+        default: jest.fn(),
+    }),
+    { virtual: true },
+);
+
+it('test apex callout', async () => {
+    apexMethod.mockResolvedValue({ foo: 'bar' });
+});
+```
+
 ### Custom matchers
 
 This package contains convenience functions to help test web components, including Lightning Web Components.

packages/@lwc/jest-transformer/src/transforms/__tests__/apex-continuation-scoped-import.test.js

@@ -13,14 +13,13 @@ describe('@salesforce/apexContinuation import', () => {
         import myMethod from '@salesforce/apexContinuation/FooController.fooMethod';
     `,
         `
+        import { jest } from '@jest/globals';
         let myMethod;
 
         try {
           myMethod = require("@salesforce/apexContinuation/FooController.fooMethod").default;
         } catch (e) {
-          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || function myMethod() {
-            return Promise.resolve();
-          };
+          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || jest.fn(Promise.resolve());
 
           myMethod = global.__lwcJestMock_myMethod;
         }
@@ -35,14 +34,13 @@ describe('@salesforce/apexContinuation import', () => {
     `,
         `
         import { otherNamed } from './something-valid';
+        import { jest } from '@jest/globals';
         let myMethod;
 
         try {
           myMethod = require("@salesforce/apexContinuation/FooController.fooMethod").default;
         } catch (e) {
-          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || function myMethod() {
-            return Promise.resolve();
-          };
+          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || jest.fn(Promise.resolve());
 
           myMethod = global.__lwcJestMock_myMethod;
         }

packages/@lwc/jest-transformer/src/transforms/__tests__/apex-scoped-import.test.js

@@ -13,14 +13,13 @@ describe('@salesforce/apex import', () => {
         import myMethod from '@salesforce/apex/FooController.fooMethod';
     `,
         `
+        import { jest } from '@jest/globals';
         let myMethod;
 
         try {
           myMethod = require("@salesforce/apex/FooController.fooMethod").default;
         } catch (e) {
-          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || function myMethod() {
-            return Promise.resolve();
-          };
+          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || jest.fn(Promise.resolve());
 
           myMethod = global.__lwcJestMock_myMethod;
         }
@@ -35,14 +34,13 @@ describe('@salesforce/apex import', () => {
     `,
         `
         import { otherNamed } from './something-valid';
+        import { jest } from '@jest/globals';
         let myMethod;
 
         try {
           myMethod = require("@salesforce/apex/FooController.fooMethod").default;
         } catch (e) {
-          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || function myMethod() {
-            return Promise.resolve();
-          };
+          global.__lwcJestMock_myMethod = global.__lwcJestMock_myMethod || jest.fn(Promise.resolve());
 
           myMethod = global.__lwcJestMock_myMethod;
         }

packages/@lwc/jest-transformer/src/transforms/utils.js

@@ -71,11 +71,12 @@ function stringScopedImportTransform(t, path, importIdentifier, fallbackData) {
  * shared.
  */
 const resolvedPromiseTemplate = babelTemplate(`
+    import { jest } from '@jest/globals';
     let RESOURCE_NAME;
     try {
         RESOURCE_NAME = require(IMPORT_SOURCE).default;
     } catch (e) {
-        global.MOCK_NAME = global.MOCK_NAME || function RESOURCE_NAME() { return Promise.resolve(); };
+        global.MOCK_NAME = global.MOCK_NAME || jest.fn(Promise.resolve());
         RESOURCE_NAME = global.MOCK_NAME;
     }
 `);

test/src/modules/transformer/apex/__tests__/apex.test.js

@@ -7,8 +7,13 @@
 import { ApexMethod, refreshApex, getSObjectValue } from '../apex';
 
 describe('@salesforce/apex/<class>', () => {
-    it('exports a default method returning a promise', () => {
-        expect(ApexMethod()).resolves.toEqual(undefined);
+    it('exports a default method returning a promise', async () => {
+        expect(ApexMethod).not.toHaveBeenCalled();
+
+        ApexMethod.mockResolvedValue('bar');
+        const result = await ApexMethod('foo');
+        expect(ApexMethod).toHaveBeenCalledWith('foo');
+        expect(result).toBe('bar');
     });
 });
 
@@ -18,9 +23,9 @@ describe('@salesforce/apex', () => {
     });
 
     it('exports getSObjectValue method returning a jest.fn()', () => {
-        expect(getSObjectValue).not.toBeCalled();
+        expect(getSObjectValue).not.toHaveBeenCalled();
 
         getSObjectValue('foo');
-        expect(getSObjectValue).toBeCalledWith('foo');
+        expect(getSObjectValue).toHaveBeenCalledWith('foo');
     });
 });