up

Author: Goaman

tests/derived.test.ts

@@ -27,16 +27,22 @@ describe("derived", () => {
 
   test("derived updates when dependencies change", async () => {
     const state = reactive({ a: 1, b: 2 });
-    const d = derived(() => state.a * state.b);
-    const spy = jest.fn();
-    effect(() => spy(d()));
-    expectSpy(spy, 1, [2]);
+
+    const spyDerived = jest.fn(() => state.a * state.b);
+    const d = derived(spyDerived);
+    const spyEffect = jest.fn(() => d());
+    effect(spyEffect);
+
+    expectSpy(spyEffect, 1, []);
+    expectSpy(spyDerived, 1, [], 2);
     state.a = 3;
     await waitScheduler();
-    expectSpy(spy, 2, [6]);
+    expectSpy(spyEffect, 2, []);
+    expectSpy(spyDerived, 2, [], 6);
     state.b = 4;
     await waitScheduler();
-    expectSpy(spy, 3, [12]);
+    expectSpy(spyEffect, 3, []);
+    expectSpy(spyDerived, 3, [], 12);
   });
 
   test("derived does not update when unrelated property changes", async () => {

tests/helpers.ts

@@ -219,9 +219,16 @@ export async function editInput(input: HTMLInputElement | HTMLTextAreaElement, v
   return nextTick();
 }
 
-export function expectSpy(spy: jest.Mock, callTime: number, args: any[]): void {
+const noReturnValue = Symbol();
+export function expectSpy(
+  spy: jest.Mock,
+  callTime: number,
+  args: any[],
+  returnValue: any = noReturnValue
+): void {
   expect(spy).toHaveBeenCalledTimes(callTime);
   expect(spy).lastCalledWith(...args);
+  !noReturnValue && expect(spy).toHaveReturnedWith(returnValue);
 }
 
 afterEach(() => {