Sometimes, we want to properly make mock throw an error in Jest.
In this article, we’ll look at how to properly make mock throw an error in Jest.
How to properly make mock throw an error in Jest?
To properly make mock throw an error in Jest, we call the mockImplementation method and throw an error in the callback we call the method with.
For instance, we write
it("should throw error if email not found", async () => {
callMethod
.mockImplementation(() => {
throw new Error("User not found [403]");
})
.mockName("callMethod");
const query = FORGOT_PASSWORD_MUTATION;
const params = { email: "user@example.com" };
const result = await simulateQuery({ query, params });
console.log(result);
expect(callMethod()).rejects.toMatch("User not found [403]");
});
to call callMethod.mockImplementation with a callback that throws and error.
Then we use
expect(callMethod()).rejects.toMatch("error");
to check the callMethod throws an error with the given content.
Conclusion
To properly make mock throw an error in Jest, we call the mockImplementation method and throw an error in the callback we call the method with.
