fix(ts-jest): fixed nullable mocks issue (#759)

closes #757 Co-authored-by: Christian Jeschke <[email protected]>
golevelup · Aug 12, 2024 · b181b8a · b181b8a
1 parent bf0f009
commit b181b8a
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diff --git a/packages/testing/ts-jest/src/mocks.spec.ts b/packages/testing/ts-jest/src/mocks.spec.ts
@@ -157,6 +157,22 @@ describe('Mocks', () => {
 
       expect(test.base).toEqual(base);
     });
+
+    it('should accept mocks returning nullables', async () => {
+      interface Test {
+        foo(): number | undefined;
+      }
+
+      const mock = createMock<Test>();
+      mock.foo.mockImplementation(() => {
+        return 0;
+      });
+      expect(mock.foo()).toEqual(0);
+      mock.foo.mockImplementation(() => {
+        return undefined;
+      });
+      expect(mock.foo()).toEqual(undefined);
+    });
   });
 
   describe('auto mocked', () => {

diff --git a/packages/testing/ts-jest/src/mocks.ts b/packages/testing/ts-jest/src/mocks.ts
@@ -30,7 +30,7 @@ const createRecursiveMockProxy = (name: string) => {
   return new Proxy(t, {
     apply: (target, thisArg, argsArray) => {
       const result = Reflect.apply(target, thisArg, argsArray);
-      if (result) {
+      if (target.getMockImplementation() || result) {
         return result;
       } else {
         if (!cache.has('__apply')) {