我正在尝试测试以下功能:
import * as config from "./config.js";
export const state = {
recipe: {},
};
export async function loadRecipe(id) {
let result;
let data;
try {
result = await fetch(`${config.API_URL}/${id}`);
data = await result.json();
} catch (e) {
console.log(e);
}
console.log(result.status);
if (!result.status === 200) {
console.log("here");
throw new Error(`${data.message} (${result.status})`);
console.log("1here");
}
const { recipe } = data.data;
state.recipe = {
id: recipe.id,
title: recipe.title,
publisher: recipe.publisher,
sourceUrl: recipe.source_url,
image: recipe.image_url,
servings: recipe.servings,
cookingTime: recipe.cooking_time,
ingredients: recipe.ingredients,
};
}
这是我写的测试。我正在使用 jest-fetch-mock
来模拟全局获取函数。如果我注释掉第二个测试并运行它,我会得到预期的结果。现在我想测试是否输入了错误的 ID。所以我用错误的数据创建了第二个测试,并模拟了 API 的结果:
"use strict()";
import * as model from "../model.js";
import * as apiResponse from "../__fixtures__/apiResponse.js";
import * as recipes from "../__fixtures__/recipes.js";
beforeEach(() => {
fetch.resetMocks();
});
describe("Request from the api", () => {
test("Received valid data", async () => {
fetch.mockResponseOnce(
JSON.stringify(apiResponse.id_5ed6604591c37cdc054bca85)
);
const res = await model.loadRecipe("5ed6604591c37cdc054bca85");
expect(model.state.recipe).toStrictEqual(
recipes.recipe_5ed6604591c37cdc054bca85
);
expect(fetch).toHaveBeenCalledTimes(1);
});
test("Requested an invalid id", () => {
const body = apiResponse.invalid_5ed6604591c37cdc054bca85zzzzz;
const init = { status: 400, statusText: "Bad Request" };
fetch.mockResponseOnce(JSON.stringify(body), init);
expect(async () => {
await model.loadRecipe("5ed6604591c37cdc054bca85zzzzz");
}).toThrowError();
expect(fetch).toHaveBeenCalledTimes(1);
});
});
每当运行第二个测试时,我都会从 yarn 收到以下错误:
RUNS src/js/__tests__/model.test.js
node:internal/process/promises:225
triggerUncaughtException(err, true /* fromPromise */);
^
[UnhandledPromiseRejection: This error originated either by throwing inside of an async function without a catch block, or by rejecting a promise which was not handled with .catch(). The promise rejected with the reason "TypeError: Cannot destructure property 'recipe' of '((cov_24wkscmv5p(...).s[10]++) , data.data)' as it is undefined.".] {
code: 'ERR_UNHANDLED_REJECTION'
}
error Command failed with exit code 1.
info Visit https://yarnpkg.com/en/docs/cli/run for documentation about this command.
请帮助我了解导致问题的原因。
最佳答案
终于!我让它工作了。我必须添加 rejects
来捕获错误。我从这个页面得到它:https://eloquentcode.com/expect-a-function-to-throw-an-exception-in-jest
test("Requested an invalid id", () => {
const body = apiResponse.invalid_5ed6604591c37cdc054bca85zzzzz;
const init = { status: 400, statusText: "Bad Request" };
fetch.mockResponseOnce(JSON.stringify(body), init);
expect(async () => {
await model.loadRecipe("5ed6604591c37cdc054bca85zzzzz");
}).rejects.toThrowError();
expect(fetch).toHaveBeenCalledTimes(1);
});
关于javascript - 使用 Jest 为异步函数编写测试,我们在Stack Overflow上找到一个类似的问题: https://stackoverflow.com/questions/65160844/