我被要求在我的测试中通过使用它来减少重复。each或者创建一个函数。我不确定如何去做。我在测试套件中有其他函数不期望错误。我假设我可以把下面两个重复的Assert放在一个帮助函数中，但是如果你有更好的建议，让我知道。谢谢。

expect(<jest.Mock>fetch).not.toHaveBeenCalled();
expect(e).toBeInstanceOf(TypeError);

测试文件：

it('should throw if no args were passed', async () => {
            expect.assertions(3);
            return readPricing().catch((e: Error) => {
                expect(<jest.Mock>fetch).not.toHaveBeenCalled();
                expect(e).toBeInstanceOf(TypeError);
                expect(e.message).toBe(
                    `The 'products' information is required to successfully be able to execute this request.`
                );
            });
        });

        it('should throw if no product IDs were passed', () => {
            expect.assertions(3);
            const noIdData = {
                products: [{ salesPrice: '60.00' }, { salesPrice: '80.00' }],
            };
            // @ts-expect-error
            return readPricing(noIdData).catch((e: Error) => {
                expect(<jest.Mock>fetch).not.toHaveBeenCalled();
                expect(e).toBeInstanceOf(TypeError);
                expect(e.message).toBe(`The 'productId' is required to successfully be able to execute this request.`);
            });
        });

        it('should throw if an empty array of products was passed', () => {
            expect.assertions(3);
            const noIdData = { products: [] };
            return readPricing(noIdData).catch((e: Error) => {
                expect(<jest.Mock>fetch).not.toHaveBeenCalled();
                expect(e).toBeInstanceOf(TypeError);
                expect(e.message).toBe(
                    `The 'products' information is required to successfully be able to execute this request.`
                );
            });
        });

我尝试使用它。每个，但未能成功地设置它，我不确定它是否可能与给定的输入。